Tag Archives: Pole Building Design

NEW Hansen Pole Buildings’ Ceiling Joists

NEW Hansen Pole Buildings’ Ceiling Joists

Because Hansen Pole Buildings provides true double trusses to eliminate possibilities of a single truss failing due to loads beyond design (read more about double trusses here: https://www.hansenpolebuildings.com/2018/09/true-double-trusses/), for ceiling applications, joists must be placed between roof truss bottom chords.

For those of you who question reliability of widely spaced double trusses, please see: https://www.hansenpolebuildings.com/2011/06/pole-barn-truss-spacing/

Installing a ceilingWhen buildings have no endwall overhangs, all roof trusses are placed with bottom chords at same height. Ceiling joists can be placed with bottom of joists and bottom of trusses at same height and connected with joist hangers.

However when end overhangs are present those roof purlins in end bays cantilever over truss on each end. While this makes for very sturdy overhangs, it does present a potential challenge – as top of end trusses are now lower than tops of interior double trusses by thickness of roof purlins.

Not an issue, until ceiling joists are present (or may be installed at a future date). Hansen Pole Buildings has solved this, by increasing heel (end of truss) height of interior double trusses to compensate for purlin thickness over ends. In a nutshell – these are raised heel trusses.

For an overview of raised heel trusses: https://www.hansenpolebuildings.com/2012/07/raised-heel-trusses/.

We have even made it easy to quickly identify lumber to be used as ceiling joists – one end will arrive spray painted BLUE. If you (or your erector) need to trim a board, please trim unpainted end, as this makes it easy for you (if you hired a builder) or an inspector, to quickly identify wood as being properly utilized!

Call 1.866.200.9657 TODAY to participate in “The Ultimate Post-Frame Building Experience”.

And, don’t forget to watch for our next article!

10 Important Things to Consider When Building a Pole Barn

10 Important Things to Consider When Building a Pole Barn

By Andi Croft.

Andi Croft is a freelance writer whose main interests are topics related to home design, business, technology, and travel. This is brought about by her passion about going around the world, meeting people from all walks of life, and bringing along with her the latest tech to enhance her adventures.

Within the construction domain, the magnetic appeal of pole barns remains potent, presenting a versatile and economically sound solution for diverse requirements ranging from agricultural storage to workshops.

Yet, the expedition from conceptualization to realization demands meticulous planning and thoughtful consideration of numerous pivotal factors.

This useful guide ventures into the exploration of ten critical elements to consider when building a pole barn.

1. Smart Pole Barn Planning

The genesis of any successful project lies in thoughtful planning. Before installing the first post, envision the purpose of your pole barn. Is it a haven for livestock, a storage facility, or perhaps a workspace?

Define your needs and consider future expansion possibilities. Strategic planning ensures your pole barn meets current requirements and adapts seamlessly to evolving needs.

Consider the pole barn’s layout, optimizing space use and ensuring efficient workflow. Whether incorporating additional storage lofts or allocating specific zones for different functions, a well-thought-out plan serves as the architectural blueprint for success.

2. Site Assessment and Conditions

Undertaking a comprehensive site assessment is akin to laying the foundation for success. Examine soil quality, drainage patterns, and topography to determine the most suitable location for your pole barn.

Factors include sunlight exposure and prevailing winds, as these elements play a pivotal role in the long-term functionality and durability of the structure.

Conduct a soil percolation test to assess drainage capabilities, preventing potential flooding or soil erosion. Evaluate the land’s natural features, ensuring that the chosen site maximizes energy efficiency through proper orientation and utilization of natural light.

3. Hiring Professional Builders

Crafting a pole barn necessitates a blend of artistry and precision. Currently (and for the foreseeable future) there is a nationwide shortage of building erectors. Many high quality erectors are booked out well into 2024 (some even 2025). We would strongly encourage you to consider erecting your own building shell. Otherwise, engage seasoned professionals who specialize in pole barn construction.

Building from fully engineered, site specific plans ensures the structure adheres to industry standards and local building codes. A proficient team expedites the construction process and minimizes the likelihood of costly errors.

Examine the credentials of potential builders, seeking out references and examples of past projects. If an erector tells you they can begin quickly it is generally either a big red flag, or there is a chance you are being price gouged. ALWAYS THOROUGHLY VET ANY CONTRACTOR https://www.hansenpolebuildings.com/2018/04/vetting-building-contractor/. Ask about their technologies – construction software, project collaboration tools, estimation, submittals, etc.

4. Understanding Zoning Rules and Regulations

Navigating the labyrinth of zoning rules and regulations is paramount to a hassle-free building process. Before breaking ground, acquaint yourself with local ordinances governing setbacks, height restrictions, and land use.

Compliance with these regulations expedites permitting and safeguards your investment against potential legal ramifications. Consult with local authorities or zoning officials to clarify any ambiguities and ensure your pole barn project aligns with community guidelines. https://www.hansenpolebuildings.com/2013/01/planning-department-3/

Failure to adhere to zoning regulations can lead to costly delays and legal complications, underscoring the importance of due diligence in this project phase.

5. Materials Selection

The choice of materials significantly influences your pole barn’s longevity and aesthetic appeal. Explore options for posts, trusses, and roofing materials, considering factors like climate, intended use, and budget constraints.

Opting for durable and weather-resistant materials ensures that your pole barn weathers the test of time while requiring minimal maintenance. Consider the environmental impact of materials, exploring sustainable options that align with your values and long-term goals.

The selection of high-quality materials enhances the pole barn’s structural integrity and contributes to its overall visual appeal and resilience against the elements.

6. Engineering and Design

The engineering and design phase is the architectural heartbeat of your pole barn. Collaborate with professionals to create a blueprint that seamlessly integrates functionality with aesthetics.

Precision in structural design enhances the visual appeal and guarantees the pole barn’s structural integrity, especially in regions prone to extreme weather conditions.

Consider the incorporation of advanced design software and technology to create 3D models, allowing for a more immersive understanding of the final product.

Engage in open communication with the design team, ensuring the finalized plans align with your vision while adhering to safety and regulatory standards.

7. Foundation and Anchoring Methods

The foundation is the bedrock of any construction project, and pole barns are no exception. Evaluate various foundation options and choose one that aligns with your specific needs.

Selecting an appropriate foundation from traditional concrete pads to modern alternatives like helical anchors ensures stability and longevity. Consider the soil composition and load-bearing requirements when determining the foundation type.

Engage with structural engineers to assess the most suitable anchoring methods, considering soil stability and potential seismic activity. A robust foundation supports the structure and safeguards against settling structural issues over time.

8. Effective Insulation is the Key

Beyond structural considerations, the comfort and utility of your pole barn hinge on effective insulation. Depending on the purpose of your structure, explore insulation options that regulate temperature and minimize energy costs.

Incorporating proper insulation not only enhances the livability of the space but also contributes to long-term cost savings. Evaluate insulation materials based on their R-value, ensuring they meet or exceed local building codes for energy efficiency.

Consider factors such as moisture resistance and fire-retardant properties to enhance the safety and durability of the insulation. A well-insulated pole barn creates a comfortable environment year-round, making it conducive for various uses.

9. Construction Time Frame

Time is a critical factor in any construction endeavor. Establish a realistic timeline, considering weather conditions and potential setbacks.

A well-planned construction schedule streamlines the process and allows for contingencies, ensuring that your pole barn is completed within the stipulated timeframe. Factor in seasonal considerations understanding how weather patterns may impact construction timelines.

Regular communication with the construction team facilitates proactive problem-solving and promptly addresses unforeseen challenges, preventing unnecessary delays.

10. Budget and Cost Management

Finances are the backbone of any project, and meticulous budgeting is non-negotiable. Factor in all expenses, from materials and labor to unforeseen contingencies.

A detailed budget prevents financial surprises and facilitates informed decision-making throughout the construction journey.

Create a comprehensive budget that includes a buffer for unexpected expenses, ensuring that you have the financial flexibility to address unforeseen challenges without compromising the quality of the project.

Regularly review and update the budget as the project progresses, keeping a keen eye on cost management to prevent budget overruns.

Conclusion

In the symphony of construction, building a pole barn requires a harmonious blend of foresight, expertise, and meticulous execution. From planning your pole barn construction to the finishing touches, each step plays a crucial role in shaping a structure that stands the test of time.

By considering the ten pivotal aspects outlined in this guide, you pave the way for a pole barn that meets your immediate needs and becomes a lasting testament to the artistry and precision of thoughtful construction.

Remember, the investment in careful planning and execution is not just in a structure; it’s in the creation of a functional and enduring space tailored to your specific needs and aspirations.

Evolution of The Pole Barn Guru and his Building Philosophy

Today we’d like to revisit the “Evolution of The Pole Barn Guru and his Building Philosophy”

In my early years, tremendous quality was not necessarily the strong point. It was the ability to offer a very reasonably priced building and deliver it quickly. My buildings were pretty much the same as everyone else I competed against. Business grew and I started being able to hire employees. Jim Betonte left the steel roofing and siding industry and began a construction business which offered labor to people who wanted our building kits erected. In the mid-80’s M & W joined the National Frame Builders Association (NFBA) and started to become better educated on the “post frame” industry on the whole.

The real deal changer – in October 1985 I met Frank Woeste. Frank was an Agricultural Engineering professor at Virginia Tech and what he knew about pole buildings was staggering. In exchange for me traveling to Blacksburg, Virginia to teach one of his classes for a day, Frank gave me my first engineering design software for pole buildings and the printout of the programs in a computer program called “Basic”.

Frank motivated me to want to make better buildings and to know why it is they worked the way they did from an engineering standpoint. From

his program printout, I taught myself Basic programming and wrote more complex and varied programs than the ones which just calculated post, girt and purlin sizes.

My buildings gradually changed – steel stopped being fastened with ringshanked nails in 1982, using first galvanized, then later color matched screws. Green lumber was replaced by kiln dried lumber, much of it (especially larger sizes such as 2×6 and 2×8 with machine stress rated lumber). Utility graded skirt boards and 4×6 columns were upgraded to #2 and better. Pressure treated timbers were treated for structural in ground use, rather than “or refusal” (basically, in many cases, just coated with treating chemicals by the treatment plants).

By 1987 I had joined the American Society of Agricultural Engineers (ASAE) and the International Conference of Building Officials (ICBO). At the time, ICBO was writing the Uniform Building Code, which was adopted throughout much of the United States. The late 80’s were heady times for the ASAE as the structures committee I was a member of, was developing and putting into practice many of the standards now utilized for modern pole building structural design.

Frank Woeste and Don Bender (now a professor at Washington State University in Pullman), began holding commercial post frame design classes, which I first took as a student, and later assisted with. Often, the example buildings for the class were structures of mine.

While I owned M&W we received recognition from the State of Oregon for our donation of a building to earthquake ravaged Irkutsk, USSR. We were featured in newspapers such as the Capitol Press and magazines such as Frame Building Professional. We were also named as one of the 50 largest users of steel roofing and siding in the United States for the decade of the 1980’s. We were even featured on the morning national television program in South Korea!

In 1989, I was elected to a 3 year term on the board of directors for the National Frame Builders Association. To the best of my knowledge, I was the first board member from west of the Mississippi River.

After some 6600 building kits sold in 13 western states, Canada, Mexico and Saipan, I sold M & W Building Supply to Jim Betonte in 1990 and moved back to Spokane. My brother Mark had worked in sales for me at M & W and in 1991 he returned to Spokane as well. We formed Momb Building Systems and began constructing buildings in the Spokane area. Mark left the business in 1992 to return to school and the name was changed to Momb Steel Buildings. Business thrived and in 1993 Apex Roof Truss was begun to produce trusses and provide the lumber packages for our buildings.

Besides Washington, I became a registered contractor in Oregon, Idaho and Montana. At the height of business, we had as many as 35 crews building in six states. In one single county alone, we built over 200 buildings in a single year.

Mike The Pole Barn Guru Featured in Frame Building Professional Magazine

Further improvements to pole building design were made. In the early 90’s we added trims which were not regularly used along the I-5 corridor.  Base trim to keep rodents out, J Channel at tops of walls, overhead door jamb trim, trims on fascias and varges with overhangs, eavelight trims with sidelight panels) all of which made for a far more attractive finished product. The first big structural change was to notch the trusses into the columns to provide direct bearing, instead of attaching them to each side of the columns. Later, we physically doubled up the trusses nailing them face-to-face, instead of blocked apart. At the same time we went to joist hanging all roof purlins between the trusses, instead of placing them lapped over the top of the truss pairs.

This now allowed for the roof panels to be predrilled before installation, which kept all screw lines straight and greatly eliminated the potential for leaks.

At an Alumax testing facility east of Los Angeles, we constructed a full scale roof to test the shear strength of steel panels. Our testing resulted in some surprises. Initially we felt the weak link would be the framing under the steel. We were totally in error and surprised at the results.  Our assembly was done to match industry standards and included fastening the steel to the roof purlins using #10 x 1” screws every nine inches. As we placed horizontal loads into the roof, before ripples even appeared in the steel, the screw started to pull out of the framing. The pull out problem was solved by using 1-1/2” long screws.

The next problem was the steel began to slot beneath the screw grommets. The solution was to use larger diameter screws in the high stress areas (at the eave and ridge) and to place screws in this area on each side of each high rib, rather than along one side only. Only after all of the screw issues were solved, were we finally able to test the steel to failure.  The results showed some fairly significant values. The results of this test are published in the NFBA Post Frame Building Design Manual  https://bse.wisc.edu/bohnhoff/Publications/Copyrighted/NFBA_Design_Manual.pdf See Table 6.1 (assemblies 13 and 14).

After the test was completed, the Alumax design engineer, Merle Townsend designed a screw specifically to solve the weaknesses demonstrated by the test. Labeled as the “diaphragm” screw (https://lelandindustries.com/productpdfs/page%2001.pdf) this 1-1/2” part features a larger diameter shank than standard screws. A side benefit of this screw is that the larger diameter helps prevent the screw heads from twisting off during installation.

To this day, these screws remain a stable part of my building design, and have rarely (if at all) has this great improvement been equaled by any other pole building company.

Stay tuned for the final episode of “From Cradle to now…Mike the Pole Barn Guru” as he expands from four states…to fifty!

 

Scary Pole Barn Design

Scary Design

A one-time potential Hansen Pole Buildings’ client, who is a friend of mine on Facebook, didn’t invest in one of our engineered post frame buildings. Most likely it was due to price – people so easily believe they have gotten a great deal, when instead they set themselves up for nothing but potential grief.

He proudly posted the photo above on Facebook of the progress of his new building.

Disclaimer – in case you, gentle reader, were unsure – his new building is NOT a Hansen Pole Building.

I will let you in on a secret which truly frightens me about this building…….

loft floor framingIf a load approaching what the loft should be designed to support is placed upon it, I venture to wager it will fail. Do not stand underneath it, by any means.

As near as I can tell from the photo, the columns which support the second floor are spaced roughly 12 feet on center. It appears the floor joists are 2×12 spaced 16 inches on center and each end of the joists are supported by what seems to be another 2×12.

Building design and construction are only as good as the weakest link.

The building is in the deep south, so we will go with the premise the lumber being used is Southern Pine.

The floor joists are not a problem – they would easily support double the normal design floor live load of 40 pounds per square foot (for residential loading). The problem comes from the beams which support them at each end.

Here is the formula for design of the beams:

(Live plus dead loads) X ½ the distance to the next beam X Beam span^2  /  8 X 31.6406 (the Section Modulus of a 2×12) X Fb (for 2×12 Southern Pine 750) X 1.15 (Cr – repetitive member increase)

(40 + 10) X (72”) X 12’^2 / 8 X 31.6406 X 750 X 1.15 = 2.37 when it has to be less than or equal to one to work.

The floor, as built, is overstressed by 237%!! Or – think of it this way, it will only support 42% of what it should support by the BuildingCode!!

In either case, it is frightening.

Don’t construct (or have constructed for you) any post frame (pole) building which has not been designed by a Registered Design Professional (RDP – architect or engineer). To do so is scary pole barn design and nothing short of playing Russian Roulette.

5 Reasons to Add a Loft to Your Pole Building

Hansen Pole LoftIt’s not uncommon to construct a loft in a pole building – after all, construction is so affordable that you’re going to be left with excess funds that you can pour right back into your investment. They take up almost no space and can sometimes even add space to an existing interior. If you’re on the fence about putting in a pole barn loft, consider the following.

1. It Looks Amazing

With a little elbow grease and a few inspiring ideas, you can create new and exciting atmospheres in your pole barn. Loft areas retain the wide open feeling characteristic of the pole building while adding an aesthetic touch that is completely customizable.

Construct a loft, then whitewash the walls and ceiling to expand the already impressive dimensions of your pole barn. Even a pole barn loft with wall support disappears into your surroundings when you treat the interior with a color that blends well in any light.

Alternatively, you can create a western look by installing distressed metallic railings alongside natural, worn, and treated wood on your loft. Accent it with secondhand or recycled furniture to cultivate an air of a time long ago.

The possibilities truly don’t end. Adding a loft in your pole building gives you the freedom to revolutionize your barn’s aesthetic quickly and easily without overhauling the entire building.

2. It Utilizes Vertical Space

Pole buildings are famously tall, which means that the ceilings can be imposing. All that extra space rarely goes to good use. It may be liberating to keep the space wide open, but if you want to maximize the potential of your pole building, you’ll want to take advantage of the wide open areas left by the unique roofing structure.

Fortunately, you can build up as high as you want. Supports for pole buildings run mostly along the frame, so you also have a large open area well below the ceiling to place staircases and ladders. That means there’s no limit to the height of your pole barn’s loft. You can even layer or bunk your loft so that you have multiple levels – just make sure your building is able to support the extra weight.

3. It Increases Storage

When there’s no more room for your stuff downstairs, move everything upstairs! A loft is like an oversized shelf – you can place things underneath it and stack them to the top, and you can place things on it safely and easily.

Even better, you can double the stairs or ladder you place to get to your loft as extra storage. Build more shelving into your stairs or underneath your ladder to expand your small storage options so there’s more room above and below your loft to put the big stuff, including furniture and appliances.

4. It’s Versatile

Even if your pole barn isn’t your house, you can still transform the extra space above into useful areas. Here are some ideas for your pole barn loft:

  • Sitting area – Place some comfy furniture and a coffee table to create a social space for coffee or casual meetings.
  • Home Office – Free your workspace at home by transforming your loft with desks, chairs, and drawers.
  • Library – Install extra shelving up top to store your vast collection of literature and reference books.
  • Craft Room – Bring in long, wide tables for crafting and build cubbies to protect your crafting materials.
  • Study – Arrange long couches and luxurious chairs to create a space for concentration and learning.
  • Game Room – Get a foosball or pool table with a bit of bar seating for game time with friends.
  • Lounge – Install a small bar with a few comfortable seats to create your own lounge area.
  • Gym – Equip your pole barn loft with workout machines and free weights so you never have to buy another gym membership.
  • Utility – Set up your washer and dryer or build a workshop in your extra ceiling space.

5. It’s Easy to Build

You can use the support from your pole barn or place your loft on its own supports, but building a loft isn’t as tough as it sounds. It’s not very time consuming and only requires a small amount of raw materials to put together. Your small investment in time and resources will increase the utility and value of your pole building many times, and you’ll enjoy having a beautiful, useful, and customizable space where there was only emptiness before.

You Can Lead a Horse to Water…Pole Building Garage

Several years ago, when Hansen Pole Buildings was a fledgling company, I worked with a client in Goldendale, Washington assisting him in designing what (in his eyes) would be his ideal dream building.

My mission has always been to deliver the “Ultimate Post Frame Building Experience™”, which is greatly helped by clients who are open minded and willing to listen to why their idea might not be the most practical.

steel-garageThis particular client needed a four car garage – simple enough sounding. In his mind the building would be 36 feet wide and 48 feet long, certainly plenty large enough to park four vehicles in.

However it was HOW he wanted to park the four vehicles which posed a challenge!

His idea was to have two overhead doors, which would be 16 feet wide. Two cars can and will fit through a 16 foot wide overhead door, provided one is careful.

In this particular case – the client wanted to place the two overhead doors side-by-side on the same 36 foot endwall.

I explained why this might prove to be a challenge, drive in car number one on the far right, park and exit the driver’s side door. Repeat with cars number two and three, moving progressively to the right with each car.

Now, drive car number four in and hope there is a sunroof, as there is no room left to swing the driver’s side door open without hitting the wall!

I also tried to express how important having ‘wall room’ is – as a place to hang things on, or lean things against. If your garage is anything like mine, every available inch of wall gets used!

Well, I did make a noble effort, however my pleadings feel upon deaf ears.

The client wanted his building, his way.

About a year after the client had completed the assembly of his building kit, I got a call from him. He loves his new building and confessed I was absolutely correct in both of the things I cautioned him about.

In reality, he would have ended up a far happier camper with a building 40 to even 45 feet in width. This would have allowed him to comfortably park his four cars, be able to swing open doors without door dings and have given him the wall space for stuff!

One of my favorite sayings goes like this…” You can lead a horse to water… but you can’t make him drink.”

Local Lumberyard Quote

Local Lumberyard + Pole Barns = Scary

Yes, the title looks to be a simple math equation. The problem with math equations is, not very many people can actually do them – at least not when they fly a desk at the local lumber dealer.

Case in point –XYZ Lumberyard with multiple state locations. (name withheld to protect the innocent).

Earlier this year, they quoted a pole barn kit package to one of our clients – 60 feet wide by 96 feet long with a 16 foot eave height. Their price was a lot lower than what one of our Hansen Pole Buildings Designers had arrived at. The client forwarded to us the quote from the local lumber supplier so we could do a comparison.

Lumber OffloadingXYZ Lumberyard’s design solution was to place a column every 10 feet with single trusses five foot on center in between the columns on “truss carriers” (basically headers). I put the same information into our state-of-the-art post frame design software and came up with sidewall columns as 6×8 Southern Pine, stressed to 60.5% of capacity.

Interestingly XYZ Lumberyard was counting on 5×5 columns to carry the loads. The 6×8 calculated by our design program happens to be 339% stronger against bending than a 5×5.

The end result, at the building’s design wind load of 90 mph (miles per hour), the XYZ building’s columns would have been overstressed by 205%!! Effectively they were designed for a 62 mph wind speed.

This building was designed using the 2009 IBC (International Building Code), where the absolute minimum design wind speed anywhere in the United States is 85 mph. There is no way the XYZ Lumberyard building will meet Code and no RDP (Registered Design Professional – engineer or architect) worth his or her salt would ever put their seal on the plans.

When it comes down to it, the XYZ design (which frankly was nothing more than a list of pieces) is downright criminal – on the basis of the under designed columns alone.

Truss carriers, XYZ Lumberyard proposed two 2×12 Southern Pine as carriers. Luckily, the roof could very well collapse before the 5×5 columns, as the carriers are overstressed by 167%. Instead of being able to carry the 20 psf (pounds per square foot) roof load they should be able to handle, these headers would have been overstressed at just over one-half of the design load.

It would have been a race to see which happen to take the building down first – the wind or the snow!

As I have said more than once, when one sells on price alone, there is always someone else willing to sacrifice quality to get to a lower price.

Or, perhaps ignorance is bliss and they are very, very happy!

It Can’t Be a Pole Barn!

If Ignorance is Bliss…..

Then these folks are truly happy.

From a July 21, 2015 article in the Salina (KS) Journal by Tim Horan, “City approves exterior plaza for field house”…….

Salina Mayor Jon Blanchard said he wants the appearance of the field house to be unique.

“It is going to be a building designed for the downtown environment that it is in,” he said. “It can’t be a pole barn. That block needs to be done in a fashion that it looks good. If we’re planning to build a pole barn, I’m wanting out of doing the building.”

(The full article can be read here: https://www.salina.com/news/city-approves-exterior-plaza-for-field-house/article_1fe85791-6e3c-5275-9f83-51fb94255243.html)

Commercial Pole BarnWhat the good (yet uniformed) mayor is missing is a “pole barn” (more properly referred to as a post frame building) can look just like any other building.

The term “post frame” comes from the major structural supports for the building being wood columns (or posts) typically embedded into the ground (although they can be bracket mounted to concrete, or similar, foundations). The “post frame” becomes the structural skeleton of the building.

No different than any other structural system – whether stick framed (stud walls), steel frame, block, etc., the exterior of a post frame building may be sided and roofed with any materials. Any materials can be T1-11, board and batten, vinyl – wood or cement siding, stucco, log look, masonry….need I say more? The difference – post frame construction happens to be the most cost effective permanent structural system for low rise buildings (generally up to 50 foot tall walls or three stories).

This particular project in Salina is budgeted at $9 million for a 69,000 square foot building, or just over $130 per square foot. From my somewhere beyond 17,000 post frame buildings of experience, is money that could have been saved had a more open minded approach been taken towards a structural design solution.

Regardless of the end use – post frame construction should be a consideration to be examined for any low rise structure.

New Post-Frame Building Design Manual

Post-Frame Building Design Manual

Back in 2000 the then National Frame Builders Association (now National Frame Building Association – NFBA www.nfba.org) published the ground breaking first edition of the Post-Frame Building Design Manual.

In the foreword, then NFBA President James T. Knight so aptly wrote:

“The movement of the post-frame building into the commercial marketplace has obviously necessitated compliance with building codes. Although agricultural buildings were exempt from building codes in many areas of the United States, this was not true when buildings were built in developed areas or where public access would occur. Since the design was not understood by building officials, and since no approved and recognized design procedure had previously existed, the suitability of the post-frame structure has often been questioned.

Today, the post-frame design concept is well developed. It has, for many years, been the subject of countless research studies and analysis conducted by qualified individuals at the university level and in the private sector. This Post-Frame Design Manual, for the first time, sets forth in one document, the post-frame design criteria that is today backed up by sound and widely accepted engineering practice.”

For those with an interest, the first edition can be viewed free online at: https://www.scribd.com/doc/29750872/Post-Frame-Building-Design-Manual

At the time of its publication, the United States was governed by three differing building codes – since then codes have been unified as the IBC (International Building Code). Now in its sixth edition (a new version is published every three years), the IBC has made many changes in the way Registered Design Professionals (engineers and architects) approach structural design solutions for wind, snow and seismic forces.

Post Frame Design ManualThe NFBA has risen to the occasion with the recent introduction of the new Post-Frame Building Design Manual! The second edition of the manual—and the first new edition since 2000—is the ultimate tool for post-frame design. Eight chapters, 200 pages, and hundreds of photos, diagrams, illustrations and design tables cover everything you need to know about designing with post frame.

The Post-Frame Building Design Manual, second edition, is a must-have for anyone who works with — or is considering working with — post-frame construction.

Hansen Pole Buildings has been honored by inclusion of one of our buildings on the cover of the new manual. In fact, it is in the center of the three completed buildings pictured!

Download YOUR copy now:

https://apps.nfba.org/Store/ProductDetails.aspx?productId=344022

SIPS

SIPs (Structural Insulated Panels)

I like cool stuff. I’m never right at the front of the line for new bright shiny things – but I am close enough to check out the first few and see if the bugs are out or not.

SIPs, in my humble opinion, are pretty cool stuff. I’ve never been asked specifically by a client to design a post frame (pole) building with SIPs for the roof and walls, but I can see it coming soon as SIPs appear to be gaining in popularity.

SIP PanelWhat are SIPs?

From www.sips.org: “Structural insulated panels (SIPs) are a high performance building system for residential and light commercial construction. The panels consist of an insulating foam core sandwiched between two structural facings, typically oriented strand board (OSB).  SIPs are manufactured under factory controlled conditions and can be fabricated to fit nearly any building design. The result is a building system that is extremely strong, energy efficient and cost effective. Building with SIPs will save you time, money and labor.”

Here, in the very near future, I will be discussing the applications with the director of www.SIPSchool.org.

I will share with my readers what I learn, pretty much as I learn it. Hopefully with some practical applications.

In my ideal dream world, a post frame (pole) building skeleton (columns and trusses) would be erected, then large SIP panels would be attached to them. For best economy length multiples of 12’ would be used, so 24 foot long panels could be placed lengthwise on the building.

The lowest wall panels could be fabricated from pressure preservative treated plywood and embedded into the ground, as needed, to meet heat loss requirements.

My “new bright shiny things” are rarely the least expensive solution, but I can’t say I’ve regretted them – especially not in my own personal buildings. I’ve done some work for myself which had to be remodeled later, as the buildings were repurposed and I hadn’t given enough thought to what future uses might be.

I am looking forward to being educated, and if SIPs turn out to be what I think they might be – the post frame/SIPs combination could become very, very popular.

Let’s Talk Building Diaphragms

New Pole BuildingWhen it comes to pole buildings, a diaphragm is a structural assembly – including the timber framing (truss chords and purlins), structural sheathing (e.g. plywood, metal cladding), fasteners and fastening patterns – capable of transferring in-plane shear forces through the cladding and framing members.

Diaphragm action is the lateral resistance to racking of the building provided by the roof and wall coverings. The design relies upon the roof to act as a deep beam supported by the endwalls. This deep beam supports the tops of the sidewall columns when they are laterally loaded by wind pressure.

When a pole building is designed using diaphragm design the strength and stiffness of the system are utilized to transfer applied horizontal loads to the ground. The system includes the roof trusses, sidewall columns, endwalls, shear connectors, chord splices and ground anchorages.

The term diaphragm is usually applied to roofs, ceilings and floors. A shear wall, is just a vertical diaphragm. Shear walls supply support for the roof and floor diaphragms transmitting forces into the foundation. A diaphragm structure results when a series of diaphragms are properly tied together to form a unit. Diaphragms and shear walls used for the lateral design of a building for a box system.

(Find helpful reading on the “box” here: https://www.hansenpolebuildings.com/blog/2011/12/lateral-wind-loads/)

The under design of any one of these (and other) crucial elements can result in the applied loads being unable to adequately transfer along the load path to the ground. Too great of a load with inadequate resistance can result in tragic results.

Designed and constructed correctly, the principles of diaphragm design result in smaller sized columns and lesser embedment requirements (think less digging and less concrete).

My friend, Dr. Kifle Gebremedhin of Cornell University, did extensive and advanced full-scale testing on a pole (post-frame) building, over a period of 16 years. His results showed post-frame buildings to be much stiffer than designers had previously believed – in other words, the design procedures being used underestimate the capacity of the buildings!

Proper design of a diaphragm system is not something the average lumberyard employee or building contractor is capable of understanding, with even a lesser chance of it being able to be done correctly.

Need a pole barn, pole or post-frame building? Rely upon experts who understand diaphragm design – the savings in materials and labor will easily outweigh the investment in paying for the expertise!

Single Slope Pole Barn

When the Requests Are Interesting

My encouragement to potential clients is to share with us your troubles and your goals – and let us structurally design for you the best solution which is a marriage between wants, needs, budget and available space.

Finding happiness in a new building, is much akin to success at finding the person to become the “ideal” spouse. If one goes into either situation with too much advice from well-meaning friends and lots of preconceived notions as to what they think they want, chances are the satisfaction level with the experience is going to be less than it could or should be.

Here is an actual recent request:

Single Slope Pole Barn“I will be building a single slope (roof and 3 sides covered with corrugated steel) pole barn similar to one of your designs online.  My ideal design is 20 by 30 with 1 foot roof overhang.  The structure consists of (3) 20 x 10 bays.  High side to be 12 feet and low side to be 10 feet with bay entry at high side.  I will only consider steel posts (8) for the vertical pole construction.  For the roofing material please include 2 each opaque roof sheathing for each bay (natural lighting).  Design to include high wind (50 mph) with 18″ snow load.  Please provide a detailed bill of material including foundation (30 to 36 inch footing depth (no slab) with bid.  I will be requesting engineered drawings.  The shipping destination is xxxxx zip code so please include shipping total and tax in bid.

I look forward to receiving your bid and perhaps purchasing your product.”

Obviously, this person felt they had their solution pretty well figured out…..

Except they neglected to do any research, which would have saved them from having to write out their wants and click submit!

Here is my take on their request:

Single slope buildings are rarely the best practical design solution. https://www.hansenpolebuildings.com/blog/2014/11/single-slope-roof/

With the building sloping only two feet across 20 feet, the 1.2/12 roof slope is not going to be conducive to moving weather off (rain or snow) and is so flat the steel warranty will be void.

Here is where the two of us are most certainly not a fit: “I will only consider steel posts (8) for the vertical pole construction.” As we don’t use columns other than wood, the specifying only considering the use of steel posts, eliminates us (as well as many others) from possibly being suppliers. The use of only eight “posts” means the 20 foot walls are going to have to span from corner column to corner column – while this might not be an issue in all steel construction, wood wall girts will be hard pressed to meet this criteria.

It also means trusses or rafters which must clearspan the 20 from wall-to-wall, which could significantly affect both project cost, as well as the interior clear (vertical) height.

For the roofing material please include 2 each opaque roof sheathing for each bay (natural lighting).” This request, especially given the near flat roof slope, is probably dooming the finished product to at least roof leaks, if not worse.

Read more about roof skylights here: https://www.hansenpolebuildings.com/blog/2014/09/skylights-2/

This client has not done his homework, as 50 mph (miles per hour) is not a high wind speed when the minimum Building Code requirement anywhere in the United States is 85 mph.

More on wind speeds here:

https://www.hansenpolebuildings.com/blog/2012/04/wind-speed/

The 18 inch snow load is not going to be what his Building Official has in mind either: https://www.hansenpolebuildings.com/blog/2013/11/design-criteria-3/

And, of course, no true pole building kit package supplier worth their salt is going to hand out a materials’ list prior to a client ordering. Why not? Read this: https://www.hansenpolebuildings.com/blog/2012/03/materials-list/

While we do include delivery to the site as part of our quotes, sales taxes are typically a different situation altogether as noted here:

https://www.hansenpolebuildings.com/blog/2013/06/pole-buildings-internet-sales-tax/

Perhaps the requirement of engineer sealed drawings will help to steer this client closer to what might be a more practical and affordable design solution while still getting his ultimate goal – a single slope roof design.

Kitty Hawk

My loyal readers know I grew up flying small planes (read more about my adventures at https://www.hansenpolebuildings.com/blog/2013/09/hangar-n3407s/).

Growing up in a flying household meant the Wright Brothers were highly revered. I’d always wondered why it is two brothers from Dayton, Ohio ended up making history at Kitty Hawk, North Carolina.

I had my first experience visiting the Outer Banks this past May. It didn’t take me but driving a few blocks down the main drag to figure out why the Wright’s came to Kitty Hawk to fly – they must have loved cheap souvenir T shirts and putt-putt golf!

Seriously, Wilbur and Orville came to Kitty Hawk due to the regular breezes and soft sandy landing surfaces.

beach houseBesides the shirts and miniature golf, there was one characteristic I noticed about many of the houses built along the Grand Banks – they are mostly built on top of platforms which are eight to ten feet off the ground and supported by pressure preservative treated wood columns embedded into the ground.

As I drove through the Kitty Hawk area, I was getting pretty “jazzed” about the whole concept – these are pole buildings!

My new found excitement was dashed, when I found one under construction and saw the treated columns did not extend above the platform.

I had to stop and talk to the builders (and snap a few photos). Asking them about the posts not being the height of the walls and all they could tell me was, “it wasn’t allowed”.

Clearly I was not satisfied with this answer, so I ventured on to the warehouse of all construction knowledge – the Pro Desk at the Kitty Hawk Home Depot. The Pro Associates there at the counter gave me the very same answer, Code would not allow columns to go past the platform.

The entire experience left me with a bad taste in my mouth. I was just not able to let this one sit, so after mulling it around for several months, it was time to go on the offensive!

I posed this question to the three Building Permit issuing jurisdictions in the Kitty Hawk area:

“I was a visitor to your area earlier this year. I noticed homes being built which were platforms on top of pressure preservative treated columns. I stopped to talk to one of the contractors and remarked how (in my simple head) it would be seemingly easier and more structurally sound for the treated columns to be extended all the way up to the roof line, rather than having a hinge point created at the platform. I was told it was “not allowed” by the Building Department. Somehow this response did not seem right, so I am inquiring to see if there exists, in your jurisdiction, some amendment to the Codes which would preclude the use of continuous columns.

 Thank you very much for your time and consideration, it is greatly appreciated.”

 All three responding nearly immediately! Here are their answers:

Buddy Shelton, Chief Building Inspector, Dare County: “IT’S NOT AN ISSUE IN THE BUILDING CODE.”

Matthew Lowcher, Chief Building Inspector, Town of Kill Devil Hills: “The type of construction method you speak about would be allowed. It just is not a typical type of construction in our area. Engineered sealed plans may be required for such a structure. The Building Code enforced in the State of NC is the NC State Building Code, which is the ICC with NC Amendments. I hope this answered your question.”

Dennis L. Speight, Building Inspector, The Town of Kitty Hawk: “I know of no code requirement, state or local, that prevents using continuous length piles.”

 My biggest takeaway from this experience is – perception and reality are not always the same thing. Both the builder I spoke with, and the supplier, were thoroughly convinced the method I suggested would not be allowed by the Code!

Orville and Wilbur made things happen which people said could not be done either!

Wind Speed & Pole Barns

Wind Happens…

…even close to home (or home of Hansen Pole Buildings anyhow) in Roberts County, SD!

Pole Barn DamageFriday, October 11, at 5:25 p.m. a tornado touched down about 10 miles northeast of Dumont, (just across the border into MN) in a soybean field. As the tornado moved to the northwest, it struck a barn which suffered significant structural damage. The steel siding from the barn was found over 50 yards away, with one piece speared eight inches into the ground and stuck standing upright!

The damage was consistent with an EF-1 tornado with estimated wind speeds from 95 to 105 mph (miles per hour).

Under the 2009 and earlier versions of the IBC (International Building Code) the design wind speeds for Minnesota, North and South Dakota are 90 mph (miles per hour). Obviously this tornado did not read the Code books, and ramped up right past the design speed.

In looking at the damage to the barn in question, my educated guess would be this building was not designed to any particular wind loading. It appears to be more of a “throw it together and see if it works” type design.

Most people do not have a real good feel for how design loads are determined. For structures with a low risk to human life in the event of failure (Occupancy Category I), the design loads are such as the building will be loaded BEYOND them, on average, once every 25 years. For homes, or similar occupancies, once every 50 years (Occupancy Category II).

This does not mean the critical event will occur against a barn once every 25 years, it means there is a 4% probability of it happening, in any given year. It could happen two years in a row, or not for 100 years. Probability works like this.

In the event owning the last building standing is important, it is a simple matter to increase the Occupancy Category, and usually with little or no cost. Want to really “beef” things up? Category III would put the building in the same risk class with structures which represent a substantial hazard to life in the event of failure (most schools fall in this arena).

Or, really go for it with Category IV, which includes essential facilities such as hospitals.

Another way to achieve a greater degree of safety, is to design with faster wind speeds, or greater snow loads. Check out all of these options, they may prove to be less expensive than you thought!

Dear Guru: Can I Get Snow Breaks From You?

Welcome to Ask the Pole Barn Guru – where you can ask questions about building topics, with answers posted on Mondays.  With many questions to answer, please be patient to watch for yours to come up on a future Monday segment.  If you want a quick answer, please be sure to answer with a “reply-able” email address.

Email all questions to: PoleBarnGuru@HansenPoleBuildings.com

DEAR POLE BARN GURU: I put gutters and downspouts on my barn this summer and now am dealing with ice sheets damming up against the gutter, and am concerned that the ice/snow backing up may bend the gutter or worse rip the gutter off the fascia. Can you tell me the solution? I see some metal roofs with plastic/metal/??? strips or triangular pieces at the lower end of the roofing sheets, and I assume these are ice breaks of some sort. Can I get these things locally, can I get them ordered through you, or through ABC Steel? How do they work, how are they attached, and do they compromise the roof water shedding? NOT ONLY IN OHIO

DEAR ONLY: 22 years ago I moved into my current home. It has a 7/12 roof slope and a steel roof. Sliding snow ripped the gutters off the very first winter, so I learned the hard way.

Snow breaks – we can provide steel snow breaks for your building (the steel company sells only wholesale, not direct to the public). They are pieces of steel trim, which attach to the roof steel with stitch screws at every high rib. On a building such as yours, we’d suggest going with two runs on each side – one at the first purlin line up from the eave and another 1/2 way up the roof. In your case this would total 14 pieces 10’6″ in length and 400 stitch screws. This product will not impede water running off your roof.

DEAR POLE BARN GURU: Trying to evade having my taxes doubled. Main goal…I want living space on top for underachieved kids. How about totally open bottom area garage doors on both ends. Or just a car port. Simple open living area on top. A small bath, two small bedrooms, open kitchen open living area. If it’s over 800sq. ft. taxes double. Any ideas on a plan and cost? KERRY IN PONTIAC

DEAR KERRY: As you did not leave an email address or any other way to contact you, we’d have to work in broad generalities. I would encourage you to discuss your desires with one of the expert Building Designers at Hansen Pole Buildings.

 I’ve never been a huge fan of design based upon evading taxes, etc. It won’t matter how much you are able to save in taxes, if your new building does not meet with your needs.

 Your lower area could be just an open carport, basically supporting the living space on stilts. This is very popular in the south where low lying lands are frequently flooded due to hurricanes.

 As we do not design for non-structural interior walls, you would have the total flexibility to place rooms as you best see fit. Your overall size limitation would allow you to do something like 20’x40’, 24’x33’, 26’x30’ or 28’ square. I’d suggest you play around some with possible room sizes….and give us a call at your earliest convenience.  99% of the time you will get a price while you are on the phone with a Building Designer.

Parallel Chord Scissor Trusses

As always, I enjoy finding real life solutions to client’s challenges.

One of the Building Designers, Rick, of Hansen Pole Buildings posed this to me today:

“Another thing came up yesterday, got a guy that wants everything, and is on a cost crunch, nothing new there, but one item that he wants is parallel chord scissor trusses.  He intends to put up a building for storage on the lower level and build office space in the second level.  Apparently he has had these in a house that he once built.” 

Yes, this can be done.

In a parallel chord truss, the top and bottom chords of the truss follow the same slope. The most frequent application of parallel chord trusses is for headers above wide span openings in building sidewalls. Provided enough depth is available, this allows for a design solution which is frequently more affordable than headers made of glu-laminated members, or LVLs (laminated veneer lumber).  Another use is for commercial buildings with a very low roof slope.

As a scissors truss, the slope of the top chord again follows the slope of the bottom chord, with both chords having a peak at the center of the truss.

There are some limitations.

As with most roof trusses, there exists a limitation on what can be manufactured and shipped down the highway. In the case of wider spans, or steeper roof slopes, the truss can be divided in half at the center; however this results in the need for an engineered field splice, which can add to the expense. To keep costs down, it is best for the overall truss height to be no greater than 12 feet.

Trusses also have to have a thickness. In low or no snow load areas, the trusses will be about an inch deep, for every foot of truss span, with a minimum thickness of about two feet. This thickness results in a loss of clear height at the eave of the building, which is going to reduce the headroom or useable space along the sides of the space.

In many cases, especially as in the example above with a second floor area, it may be more affordable to utilize a pole and raftered solution.

The pole and rafter building would have interior columns set in a grid, to support the lower (loft) floor. The columns extend through the floor and up to the rafters. This gives the same resultant as the parallel chord scissors truss, while taking up less thickness. The tradeoff is, the upper level will have columns in it.

An example would be a 36 foot square building, which (in the pole and raftered case) would typically have four interior columns placed on a 12 foot grid.

Don’t get me wrong.  I am in total support of scissor trusses.  My step-son put them in his Mother-in-law apartment in the upper story of his garage, which made for a much roomier feeling apartment.  It also afforded putting a ceiling fan up higher and out of the way of having fan blades accidentally cutting through someone’s hair.

My caution is to weigh the advantages with the cost, and then go with whatever is going to make you happiest in the long run.

Nailed-Up Glulam Columns

Glulam Columns

Recently one of the clients of Hansen Pole Buildings asked us to compare our building, to one being quoted by another supplier.

One of the “features” of the other providers building was building glulam columns which were built out of three 2×6’s which were both glued and nailed.

Whilst our client believed these to be a true glu-laminated column (and the other supplier promoted them as such), this is not at all the case.

These particular columns are constructed with pressure preservative treated lowers, finger jointed on to a non-treated upper. So far, so good – the finger joint is far superior to columns which are butt end spliced either with no reinforcement, or with a steel plate at the splice. A successful finger joint is the most difficult part of the glulam column process, and these people have it down.

The manufacturer then spreads construction adhesive on the faces of each ply and uses a through fastener (stainless steel wire) to keep the plies together.

Therein lies, “the rub”. In concept the construction adhesive reduces the potential “slip” between the plies, making the column stiffer in the weak axis.

The reality is, construction adhesive is still only construction adhesive, and the potential for slippage between the members still exists.

In a true glu-laminated column, after laminating lowers to uppers with the same finger jointing process, each ply is face sanded. Fully water-resistant phenol-resorcinol adhesive is then applied, and the assembly is pressed together and cured in a temperature controlled environment.

The finished glulam column truly becomes a solid piece of timber. It resists warp, twist and cup far better than the construction adhesive and mechanically fastened column (as there is no potential for movement between the plies) and it is less flexible in the weak (skinny) direction as it is impossible to have between ply slippage.

I realize many consumers would not know the difference, but in my experience – a little research and a few “hard questions” gets the answers you may need to make your final decision.  My beef here is the company probably doesn’t know the difference, and is purporting them to be something….they are not.

Timbers and Steel Connectors

Many of you are by now familiar with Jim, one of the senior Building Designers at Hansen Pole Buildings. Jim is great – he has an investigative mind, so poses many marvelous questions to me, many of which are incorporated into this blog.

Today Jim asked me what I knew about a particular building system which utilizes rough sawn timbers, along with 3/16 inch thick steel connectors.

Visiting their website, I was quite impressed with the claim of, “Since 1983 xxxxx has helped
hundreds build a living, working, or storage space using rough cut lumber and xxxxx steel joinery. This alternative to trusses and conventional pole building methods, saves material, labor, equipment and money. Everyone can now build a perfect Pole Barn, Garage or Home of their very own home
!”

And what a great list of benefits: “Eliminate trusses, makes room for a second floor, uses rough-cut 6″x6″ lumber or wood members, eliminates treated wood saving the environment, frames can be PULLED upright without a crane, frames DO NOT sit in concrete to eventually rot, frame assembly done on the ground, allows for lower eaves and higher door openings”.

On the face of everything, my first thought was – this is too good to be true! Perhaps this is a system we (Hansen Pole Buildings), should be offering to our clients.

Timbers & Steel

Timbers & Steel

When something appears to be too good to be true, there are times it is. So, out come the research caps, as we dig through the available information to determine if this is even a viable system.

A 2009 press release from the manufacturer of this particular series of products touts them as being “approved for stick-post building by the 2006 International Building Code”. In order to be approved, the product would have an ICC (International Code Council) approval number. I know we at Hansen Pole Buildings utilize numerous products in our building systems which have ICC-ES approval numbers. Luckily, ICC has provided the ability to search for approvals, and none were to be found from this particular manufacturer. Perhaps this is merely an oversight.

In the FAQs on the company website I found, “What if my code calls for 130 mph wind-loading? Can I use xxxxx? A. YES, with modifications. Our generic engineering to 80 mph is satisfactory for the vast majority of building applications, but where severe conditions exist those buildings we recommend you engage a professional engineer.”

Most consumers are unaware the minimum Building Code design wind speed in the United States is 85 miles per hour (mph) and most of the country is 90 mph or greater!

Far too many permit issuing jurisdictions do not require engineered plans to acquire building permits. Some do absolutely no plan reviews or inspections! This particular product may have a “home” for use in those areas. In areas of the country which do require more stringent plan reviews, the idea of the consumer having to hire their own engineer to prove a manufactured product is adequate for the intended use, just does not sit well with me.

Now I am not condemning this product, or ones similar to it. They may very well be the greatest thing since sliced bread – personally, without more verification being provided, I’d be inclined to avoid this one.  If you have better information than I found on it…be sure to let me know.  I am always willing to listen, and learn.

Hurl Your…Concrete Cookies

I know none of us has ever experienced this condition, but we all know of someone who has had the hurling issue, often after a period of personal discussion with some of the friends of George Thorogood.

In this instance, I’m not thinking either of the example above, or the tasty oatmeal raisin cookies my grandma made for us when we were kids. I am making specific reference to the pre-cast chunks of concrete usually four to six inches in thickness and 12 to 18 inches in diameter which are sold or provided for footings in pole buildings.

The basic concept is to throw concrete cookies in the bottom of the augered holes and place the building columns directly upon them. The general idea is for the cookies to support the weight of the building, to prevent settling.

My recommendation – RUN, DO NOT WALK, away from this as a design solution.

Why?

They are a failure looking for a place to happen.

Let’s look at what a footing is supposed to do. The dead weight of the building PLUS all imposed live loads must be distributed to the soils beneath the building. Sounds pretty simple, eh?

Concrete Cookie

Concrete Cookie

To begin with, the International Building Codes require concrete footings to be a minimum of six inches in thickness. This eliminates immediately any concrete cookies which are less than this thickness (most of them).

Examine a fairly small example – a 30’ wide building with columns spaced every eight feet. The actual weight of the building (dead load) will vary greatly depending upon the materials used. Steel roofing and siding will be lighter than shingles and wood sidings. For the sake of this example, we will use a fairly light 10 psf (pounds per square foot) building weight. The Code specifies a minimum roof live load of 20 psf. This means each footing must carry the weight of one-half of the width (15 feet) times the column spacing (8 feet) times 30 psf. Doing the math, 3600 pounds.

In many parts of the country soil bearing pressures are as little as 1500 or even 1000 psf. Basically – the easier it is to dig, the lower the capacity of the soil to support a vertical load.

For every foot of depth below grade, the soil capacity is increased by 20%. Other than with 1000 psf soils, for every foot of width over one foot, the capacity also gets a 20% increase.

With 1500 psf soil, and the bottom of the footing four feet below grade, a 12 inch footing will support 2700 pounds per square foot.

A 12 inch diameter footing covers 0.785 square feet, a 16 inch 1.4, 18 inch 1.77, 24 inch 3.14.

The 16 inch footing would support exactly the 3600 pounds from the example above. However – lots of places in the country have snow loads (which the footings must support) and many buildings are wider than 30 feet, or have columns placed over eight feet apart.

Trying a 40 foot span, with a 40 psf roof snow load, same eight foot column spacing, would mean resisting an 8000 pound load! With 1500 psf soils, even a two foot diameter footing would be inadequate.

In most cases, the use of concrete cookies as footing pads proves to be both inadequate and a waste of good money. To insure a building won’t settle, (from inadequate footings), look for a plan produced by a registered design professional who is proficient in post frame building design. He/She will have the history and training to design your building to withstand the loads…which begins with the foundation.

Pole Barn Truss Spacing Rerun

Happy 4th of July!

On holidays, I take a day to relax, and “re-run” some of my most highly read blogs.  From over a year ago, today’s subject has been viewed close to 8,000 times.  Yes, that’s 8 thousand. So here you go, for what I consider one of the hottest topics in pole building design: Pole Barn Truss Spacing

What do you mean they aren’t 2 feet apart?

Back in the day (early 1990’s) I was on the National Frame Builders Association (NFBA) Board of Directors. One of my fellow board members from the Midwest wanted to take a peek at how pole barns were constructed in the West, so I invited him out for a tour.

After spending a day looking at several of our building projects, his comment to me was, “The inspectors in our area would never let a pole building be constructed with roof trusses placed every 12 feet”.

Twenty years later, I beg to differ. Hansen Buildings has buildings in each of the 50 states and all of them have roof trusses on what my board member friend would describe as being “widely spaced”.

Framed Pole Barn

Modern truss design is highly computerized. Enter the span of the truss, bay spacing and load conditions and the engineering programs will design a truss spacing which will meet the design criteria. The lumber and steel plates the trusses are constructed from, have no idea how far apart they are going to be placed.  They are inanimate! Yet, somewhere in the deep, dark reaches of history, lies the theory wood trusses must be spaced no more than 24” on center, or maybe 48”, or perhaps even eight or ten feet? The reality is, there is no magic number.

While H. Howard Doane is credited with being the innovator of the modern pole barn, it was his Agricultural Service farm manager, Bernon Perkins, who is credited with refining the evolution of the modern pole building to a long-lasting structure.  It was Perkins who pioneered roof purlins being placed on edge. With this design change, roof trusses could be placed 12 feet apart, making it possible for roofs to support the loads to which they would be subjected.

I’ve had roof truss manufacturers try to convince me it is impossible to place wood trusses at spacings of over every 4 feet. Their defense is, “Our engineers will not allow us to”. The manufacturers of the steel roof truss plates (also referred to as gussets or Gang-nails), provide the engineering design for pre-fabricated wood trusses. Their programs will allow for trusses to be placed on 12 foot or even 16 foot centers, and their engineers will place their engineer’s seal on the drawings to verify.

The practicality, cost effectiveness and ease of construction of pole buildings is based upon efficient use of the fewest amount of materials, to do the most work, within safe engineering design. Hundreds of thousands of pole barns are in use today with truss spacing every 12 feet, or even more. They stand as a tribute to the ingenuity of modern pole building design.

 

The Late Steve Jobs on Design

“Design is not just what it looks like and feels like. Design is how it works.” – Steve Jobs

When it comes to creating breakthrough products and services, corporate innovators can be great at designing ideas because in many ways, the creation process is the more exciting part of innovation.

But a lot of hard work is required to figure out how the “ideas” or “design” should work, and this means devoting time and resources to guarantee its success.

If it looks simple…, easy…, someone has invested a tremendous amount of time talent and energy to get it there. The devil is ALWAYS in the details, and the simpler the design, the more complex the design process.

Pole buildings were originally a breakthrough product, having been developed as farm buildings during the material rationing days of World War II. The concept was simple – enclosed the greatest amount of space, with the least amount of material which will structurally carry the loads.

The simple garage, shop or barn alongside the road, is not all so simple. In the case of the current Hansen Pole Buildings, over two decades of work has gone into writing our proprietary software used to design your new building. A “hard copy” of the calculations for even a simple building can result in a stack of paper approaching 200 pages!

How thoroughly are members (framing pieces) checked? Every direction possible for climactic forces (such as wind, rain and snow) and seismic forces, as well as construction loads and the weight of the building itself.  Our engineering program runs all the mathematical calculations as if these forces are applied to every piece of the building.  It then chooses the appropriate lumber and parts to put them together (ledgerloks, bolts, LSTA straps, nails etc.) to ensure every building is designed to not only meet, but exceed stated code requirements.

Going a step further, we often engage in “live” testing. Rather than assuming values, there is nothing better than “tested proof”.  A few years ago we tested a full sized roof in a laboratory – we wanted to find the shear strength of the roof steel, a value used to calculate the performance of the building in resisting horizontal loads. In order to test the steel, the screws had to hold the steel securely. However, the “industry standard” screw failed miserably to hold the steel panels in place for the test. The project engineer then designed for our use a special “diaphragm” screw, which successfully held the steel, and did not become the weak link of the test. The results of our testing are published in the National Frame Building Association’s (NFBA) Post-Frame Building Design Manual. This is the same screw we use in all our buildings.

Invest in good design, elegant design, simple design… it takes longer but you will have a winner in the end!

Building Design: Best Client Line Ever

Sometimes a client will put forth a statement which says more than anything I could ever write.

Bob, one of the Hansen Pole Buildings Building Designers, was talking on the phone with one of his clients this morning. Bob shared this with me:

“Competitor was trying to tell my client that more posts and trusses are better than our system.  Client wasn’t buying it and told the guy “Listen Pal, I’m not looking for the best price per pound, I’m looking for the best design.””

For the most part, I have never looked upon myself as being a great innovator, when it comes to pole buildings. But, I have always felt I was blessed with the ability to look at how others do their structural building designs and do an impartial analysis of them.

The buildings Hansen Buildings provides today, barely resemble the ones I first designed and sold back in 1980 at Lucas Plywood and Lumber in Salem, OR.

By looking at what other people do which is good, then trying to make those things better (and incorporate those improvements), my firm belief is we have created the best possible value for the dollars invested by our clients.

In the case of the quote above – certainly we could design to place posts at any spacing desired. In most instances, spaced every 12 feet turns out to be the most efficient from engineering vs. cost standpoint. The side benefit is there will be fewer holes to dig. Unless one would happen to be part gopher, most are like me – we hate digging holes. With a passion. In many cases, the “more posts” are smaller in size or lower strength posts…..in which case, what was the point?

More trusses do not a stronger building make. Having spent what seems now like a past life either building, selling, designing or owning in the prefabricated roof truss industry, I do know just a little bit about it. Whether a truss is placed every 24 inches or a pair of them is placed every 12 feet, the trusses are designed for the given snow and wind loads – at the spacing they will be placed at. Connections are an issue, most building failures come from connection failures. The more individual trusses, the more individual truss to bearing support locations, the more the probability of one of those connections being under designed or improperly installed (either of which could result in a catastrophic failure).

At the end of the day, it is truly about the best building design, not the best price per pound.

Verifying Design Wind Speed

A client from Florida and I have been discussing wind speeds. The data we show in our system for his county was for the design wind speed to be 120 mph.

Now where do we get our data? In many cases, direct from Building Departments. In other cases, we use the wind speed maps published in Chapter 16 of the International Building Codes, or the maps from ASCE (American Society of Civil Engineers) 7. The Metal Building Manufacturers Association (MBMA) also lists design wind speeds, by county.

This particular client had also gotten a quote on an all steel building, and they used a design wind speed of 138 mph. At these speeds 18 mph can make a significant difference in structural design.

Now I know 18 mph does not sound like much, but in the formula to convert from miles per hour, to pounds per square foot of load, the wind speed is squared! While 138 is only 15% faster, the effective load placed on the building is over 32% more. Huge difference.

I asked the client if he had discussed the design wind load with his Building Department. He had, and his Building Department did have a solution which I was unfamiliar with. I like learning new things. I learn new “stuff” every day.

His Building Official had him go to: https://www.atcouncil.org/windspeed/ which finds the design wind speed for any given latitude and longitude in the country. What if you do not know the latitude and longitude? On the same website is information on how to look it up! Technology is so great when it works.  Many thanks to this Building Official for this new “tool” I can add to my internet reference toolbox.

When Building Departments establish design criteria, those are the “minimum” design loads. When it comes to wind, I would recommend everyone use the link above to check their own actual design wind speeds. In the event the speed shown happens to be greater than your Building Department’s requirements, we would strongly recommend using the higher speed.

Many times it costs very little to increase the wind resisting ability of your new pole building. As more buildings fail due to wind, than any other cause, this is not a place to be penny wise and pound foolish.

Lateral Wind Loads: The Shoebox

Here is an easy home activity, which will give you an idea of how buildings work.

Find a discarded shoe box; remove the top and any contents. Now turn upside down on a countertop. With one hand, push gently downward on the inverted box, enough so as to limit the ability of the sides to easily slide across the countertop. Now push on one of the long sides of the box. The box remains stable.

This is how buildings work to resist lateral wind loads when they have few or no openings.

Now, cut one of the ends out of the box. Repeat the steps above and notice how the box will collapse either when pushing downward (if too much force is used), or from pushing sideways (doesn’t take much).

Buildings work much like unibody cars or airplanes – the “skin” is what is doing the work. Think about how well you imagine a plane would fly, if you were to remove a portion of the skin!

Yes, I am going somewhere with all of this……

You are going to construct a new pole building. Being an astute shopper, you’ve checked with your local lumber yards and browsed the ‘net before settling on the building which works best for you. Included with the complete pole building kits are plans which are designed specifically for your needs. All of the climactic loadings are correct to your local code requirements (snow, wind and seismic). Every door has been placed on the plans, with the appropriate framework to ensure stability.

After a cursory review, your local Building Department issues a building permit, so you can begin construction.

Now, the fun begins – you decide to make some changes – adding a door, or maybe just an extra opening for access. No big problem, right? After all, there is plenty of material!

Problems….problems….problems….just putting a “hole” in one of the walls in the form of a finished opening, can change your building from acting as a fully enclosed building, to acting as a partially enclosed building. This can result in lateral wind loads being placed against members and connections which are 1/3rd or more greater than what the building was designed to withstand.

Not good.

OK, so the hole gets covered by a door. Problem solved? Maybe, maybe not – doors do not transfer lateral wind loads from the roof to the ground the way solid walls do. Remember our shoe box with the end removed? If too much wall is removed, your building will behave just like the shoe box did…and go flat.

There is a happy ending….when you invest in a new building, make sure to plan in advance to include all of the doors and openings you will need not only now, but into the future. If doors are added later, consult with the original provider, so they can provide updated structural engineering which will incorporate the changes.

Building Design: The Greatest Buildings Never Built

My mother used to have a saying, (watching my brother and I bandy about with many a sharp object), “it’s all fun until someone gets their eye poked out”.  In her stern voice, she was simply trying to make things safe for my bro’ and me.

You might have a totally sweet concept for your ideal dream pole building. An architect can design for you the most amazing project on paper, but some of the best ideas simply cannot be built. Every design must take into consideration elements, such as construction variables, materials, load weights, building codes, and cost which are necessary to bring paper drawings to life. In a Wall Street Journal article, some of the most amazing architects throughout history have designed buildings which were stricken with issues which made it impossible to construct their vision. See Wall Street Journal article at:

From Building Design to Reality

Even with today’s sophisticated programs, there are many designs with a fair amount of issues which create havoc when trying to move from a brilliant concept to the structural design stage.

With software programs, such as Hansen Buildings Instant Pricing, the pole building industry is able to bridge the gap between your vision and building reality. This proprietary program anticipates and solves issues during the pole building design stage, thereby reducing and eliminating headaches in the construction stage.  In 1956, if Frank Lloyd Wright had designed an electronic, 3D model of his proposed mile-high skyscraper, he would have been able to resolve its issues.  His challenges included the space and load bearing requirements to occupy a 528-story elevator system. With the proper software (and lots of money), Wright may have seen his vision come to life.

Construction software programs can not only design whole pole buildings, but they also allow for specific design of the most complex areas on any structure, such as roof trusses. If a roof fails, the whole building can fail, thereby making the roof truss one of the most important elements in the design process. Most design professionals agree elements such as roof trusses should be designed only by an experienced truss designer. Having the necessary experience, truss designers can take into consideration geometric volume (roof cavity) and the ability of truss components to perform given the building requirements.

Regardless if you’re designing a roof truss, a pole barn or a mile-high skyscraper, the vision and structural design requirements must harmoniously coexist before the first piece of material is cut.

Often I am challenged by folks wanting to design a pole building which may have possibly been done before, but not with the same design loads and dimensions.  And sometimes, I am put to the test to design a “pole barn” which looks nothing like any pole building you or I have ever seen before.  I rely upon solid calculations, design loads and a software system which can test them out for me.  If it isn’t solid and I can prove it on paper, I don’t want to see it built.  Just like my Mother taught me, “safety first”.

Pole Building Design: Do It Right

Pole Building Design: Do It Right

Stressed Pole Building

Logs as poles won't cut it

Old Pole Barn

Unfit Pole Barn Construction

The photos above and quote below are an actual posting on a discussion website I belong to:

“i got this late 60’s 102’x56′ pole barn/shelter.

The poles are set 11’center squire.

The purlins(nailed with 3 spikes each end)to the poles.
rafters are 2×6,4′ apart,then 1×8 boards across and metal roofing on top.
The highest part is 16′ feet high and runs the full 102’lenght. the roof there spans 22′ between the poles.(look at the dinky construction of the rafters)

I got between 1 and 2.5′ of snow on it now,i wonder how much it’ll hold before it’ll come south No deflection of rafters or purlins detected yet

My humble opinion was to donate the building to the local fire department, so it could be used for firefighting practice.

In discussions back and forth with the building owner, it turns out he has the snow manually removed from the roof of this building every single winter. Frankly, I am amazed the building will stand up under its own weight.

Buildings such as this one are why I am an advocate for every building having to have a building permit, and engineered plans having to be submitted in order to acquire a permit. This has nothing to do with me believing governments should restrict what an individual can do with one’s own property.  It is about the mandate of Building Departments to protect against potential loss of life from unsafe structures.

Just to give a broad overview of some of the potential structural issues with this building….

The “posts” are obviously just logs.  As such, they are untreated and have undergone no real “inspection” for structural defects.   Any wood in contact with the ground should be appropriately pressure preservative treated.  It would be nice if it was also graded according to acceptable grading standards.

To give the benefit of the doubt, we will assume the lumber used is all #2 Southern Yellow Pine (SYP) as it has the highest strength values of domestic softwoods available on a retail level.

The 2×12’s (“purlins”) which span 11’ and support rafters spanning 11’ are “only” about 30% overstressed, using a minimal snow load of 20 pounds per square foot. The three spikes at each end had better be big ones, as they need to support in excess of 1400 pounds of load (I’ll keep using the same above minimal snow load).

The 2×6 rafters spanning 11’ and four foot on center are more than 50% overstressed. (This just makes my heart beat faster!)

And the 22’ span which the building owner says, “look at the dinky construction of the rafters” is nothing short of frightening.  (Ok, I am never going near this building, much less into it.)

My real point, in all of this, is you have one chance to have a new building done right or wrong. “Saving” money, only to create a potential failure which could injure or kill you, or a loved one, or destroy the valuables which the building is meant to protect, is just not worth it. Make the choice to do it right.

Contact a reputable pole building kit supplier, where they do pole buildings every day, all the time.  Shop around and do comparisons on pole building design so you know you are getting what you paid for, and at a decent price. But more than anything, ask lots of questions so you know they are not “cheaping out”.  After all, it’s your building.  Your money.  And it darn well better be…your safety.

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Green Buildings: The Economics of Building with Wood

Green Buildings: The Economics of Building with Wood

Pole Buildings are a great green building solution

Anyone can equip a building with a few energy efficient features and call their product “green”, but a true move to sustainability in low rise buildings means improving the building process itself. In an industry as fragmented as construction, doing so demands a major investment in time, energy and capital. Every facet of the design and materials delivery process must be integrated, considered and evolved in order to truly “go green”. It is not like you can just have a builder pick up his cell phone and order up a fully integrated maintainable building system.

Or can they? For nearly ten years Hansen Buildings has been earning a reputation for sustainable construction solutions.

Speed is a huge factor, as for building owners time is money. The time and energy it takes for an individual or builder to design a building, source the materials and get them delivered to site is tremendous.

The process all begins in source code. Literally hundreds of thousands of lines of computer programming allow every last component in a Hansen Pole Building to be checked for structural accuracy as well as cost efficiency. Over twenty years of development have gone into a system which is being constantly upgraded and refined to produce the most efficient design solutions, with the least amount of waste.

Each structure is completely and accurately modeled using Computer Aided Drafting (CAD). Hansen Building’s Designers and engineers analyze all of the structural components and systems – from the architectural concept through the structural designs.

Materials are selected from the most trusted sources and suppliers, using Sustainable Forest Initiative Certified Sources when available. Modern pole building design is an environmentally sensitive alternative to traditional construction methods.

Hansen Buildings is not just a solution for single story structures. We’ve designed and delivered materials for buildings as tall as 44 feet and with three stories, and have the technology available for even taller!

Few can deny the ecological benefits of building with wood structural components. Wood outperforms steel and concrete because it requires less energy in production, produces fewer greenhouse gas emissions, releases fewer pollutants into the air and water and generates less solid waste.

Analysis indicates constructing a wood framed pole building with equal structural features costs considerably less than a concrete or steel framed building. Those savings, combined with the significant materials management and times savings of the Hansen Buildings process yields a winning combination for building owners seeking an economical alternative to other construction options.  Green buildings are definitely the wave of the future!

Even something as “big” as a pole building, you can definitely…”go green”!

To receive more pole building tips and advice subscribe to the pole barn guru blog!

More High Wind News – Pole Buildings Can Withstand Strong Winds

Forces of wind on a buildingPole buildings can be easily designed to withstand hurricane and tornado wind loads. The article below is from www.technewsdaily.com May 26,2011 and speaks to housing design under high winds.

 

 

 

Redesigned Roofs Withstand High Wind Events

The tornado that stormed through Joplin, Mo., on May 22 shredded an estimated 8,000 buildings and stranded desperate families that now must decide whether to rebuild or find a new home. For those choosing to rebuild, Rima Taher, an expert on wind-resistant structures, has a bit of advice: don’t do it the old way.

“You wonder why we keep doing the same things, making the same buildings,” Taher told Innovation News Daily.

By analyzing debris from hurricanes, Taher has come up with a set of guidelines for building new homes in areas prone to extreme weather.

“There are similar problems. So, what usually works for tornadoes would work for hurricanes,” Taher said.

When wind hits, the roof provides the most critical defense. But during a hurricane or a tornado, the roof is often the first to go. Taher found that increasing the number of slopes on a roof improves the aerodynamics of the structure and greatly reduces the amount of pressure exerted on it. She recommended building a roof with at least four slopes, rather than a traditional gable roof that has only two.

As wind swirls around a house, it can push on the roof from both the inside and outside. Taher suggested installing a moveable flap close to the seam of the roof. During hurricanes and tornadoes, the flap would open, stabilizing the air pressure. In hot weather, the flap would provide ventilation.

 

Taher also recommended spending a bit of extra money on hurricane clips that attach the roof more firmly to the walls than nails or staples alone.

Researchers at the Center for Building Science and Technology in France tested the recommendations by placing wooden models in a wind tunnel and used the results to design a “cyclonic home” that has twice the wind resistance a traditional home.

Moreover, most of the suggestions are simple to execute and well worth the investment.

“A lot of the things we suggest don’t really cost a lot of money. The expense is really minimal compared to the benefits,” Taher said.

Applying modern technology to pole building design, the roof trusses are directly connected to the columns, which are embedded in the ground. Rather than even depending upon light gauge “hurricane” clips for wind uplift resistance, seven gauge steel plates, attached with 5/8 inch diameter through bolts can create a positive anchorage between the roof and the walls. Low cost ventilated ridge caps help to equalize internal and external pressures, to relieve some of the uplift forces. Pole buildings can also be easily designed with roof systems having gables or hips in multiple directions to improve aerodynamics.

Hansen Buildings provides custom designs, including multiple gables, hips or other features to increase wind uplift resistance.  Alternate designs, using T’s, L’s, gables and just about any design you can think of is possible.  My feeling is, if a pole building can be structurally designed to meet code, we will find a way to produce the pole building kit!

Evolution of The Pole Barn Guru and his Building Philosophy

In my early years, tremendous quality was not necessarily the strong point. It was the ability to offer a very reasonably priced building and deliver it quickly. My buildings were pretty much the same as everyone else I competed against. Business grew and I started being able to hire employees. Jim Betonte left the steel roofing and siding industry and began a construction business which offered labor to people who wanted our building kits erected. In the mid-80’s M & W joined the National Frame Builders Association (NFBA) and started to become better educated on the “post frame” industry on the whole.

The real deal changer – in October 1985 I met Frank Woeste. Frank was an Agricultural Engineering professor at Virginia Tech and what he knew about pole buildings was staggering. In exchange for me traveling to Blacksburg, Virginia to teach one of his classes for a day, Frank gave me my first engineering design software for pole buildings and the printout of the programs in a computer program called “Basic”.

Frank motivated me to want to make better buildings and to know why it is they worked the way they did from an engineering standpoint. From

his program printout, I taught myself Basic programming and wrote more complex and varied programs than the ones which just calculated post, girt and purlin sizes.

My buildings gradually changed – steel stopped being fastened with ringshanked nails in 1982, using first galvanized, then later color matched screws. Green lumber was replaced by kiln dried lumber, much of it (especially larger sizes such as 2×6 and 2×8 with machine stress rated lumber). Utility graded skirt boards and 4×6 columns were upgraded to #2 and better. Pressure treated timbers were treated for structural in ground use, rather than “or refusal” (basically, in many cases, just coated with treating chemicals by the treatment plants).

By 1987 I had joined the American Society of Agricultural Engineers (ASAE) and the International Conference of Building Officials (ICBO). At the time, ICBO was writing the Uniform Building Code, which was adopted throughout much of the United States. The late 80’s were heady times for the ASAE as the structures committee I was a member of, was developing and putting into practice many of the standards now utilized for modern pole building structural design.

Frank Woeste and Don Bender (now a professor at Washington State University in Pullman), began holding commercial post frame design classes, which I first took as a student, and later assisted with. Often, the example buildings for the class were structures of mine.

While I owned M&W we received recognition from the State of Oregon for our donation of a building to earthquake ravaged Irkutsk, USSR. We were featured in newspapers such as the Capitol Press and magazines such as Frame Building Professional. We were also named as one of the 50 largest users of steel roofing and siding in the United States for the decade of the 1980’s. We were even featured on the morning national television program in South Korea!

In 1989, I was elected to a 3 year term on the board of directors for the National Frame Builders Association. To the best of my knowledge, I was the first board member from west of the Mississippi River.

After some 6600 building kits sold in 13 western states, Canada, Mexico and Saipan, I sold M & W Building Supply to Jim Betonte in 1990 and moved back to Spokane. My brother Mark had worked in sales for me at M & W and in 1991 he returned to Spokane as well. We formed Momb Building Systems and began constructing buildings in the Spokane area. Mark left the business in 1992 to return to school and the name was changed to Momb Steel Buildings. Business thrived and in 1993 Apex Roof Truss was begun to produce trusses and provide the lumber packages for our buildings.

Besides Washington, I became a registered contractor in Oregon, Idaho and Montana. At the height of business, we had as many as 35 crews building in six states. In one single county alone, we built over 200 buildings in a single year.

Mike The Pole Barn Guru Featured in Frame Building Professional Magazine

Further improvements to pole building design were made. In the early 90’s we added trims which were not regularly used along the I-5 corridor.  Base trim to keep rodents out, J Channel at tops of walls, overhead door jamb trim, trims on fascias and varges with overhangs, eavelight trims with sidelight panels) all of which made for a far more attractive finished product. The first big structural change was to notch the trusses into the columns to provide direct bearing, instead of attaching them to each side of the columns. Later, we physically doubled up the trusses nailing them face-to-face, instead of blocked apart. At the same time we went to joist hanging all roof purlins between the trusses, instead of placing them lapped over the top of the truss pairs.

This now allowed for the roof panels to be predrilled before installation, which kept all screw lines straight and greatly eliminated the potential for leaks.

At an Alumax testing facility east of Los Angeles, we constructed a full scale roof to test the shear strength of steel panels. Our testing resulted in some surprises. Initially we felt the weak link would be the framing under the steel. We were totally in error and surprised at the results.  Our assembly was done to match industry standards and included fastening the steel to the roof purlins using #10 x 1” screws every nine inches. As we placed horizontal loads into the roof, before ripples even appeared in the steel, the screw started to pull out of the framing. The pull out problem was solved by using 1-1/2” long screws.

The next problem was the steel began to slot beneath the screw grommets. The solution was to use larger diameter screws in the high stress areas (at the eave and ridge) and to place screws in this area on each side of each high rib, rather than along one side only. Only after all of the screw issues were solved, were we finally able to test the steel to failure.  The results showed some fairly significant values. The results of this test are published in the NFBA Post Frame Building Design Manual  https://bse.wisc.edu/bohnhoff/Publications/Copyrighted/NFBA_Design_Manual.pdf See Table 6.1 (assemblies 13 and 14).

After the test was completed, the Alumax design engineer, Merle Townsend designed a screw specifically to solve the weaknesses demonstrated by the test. Labeled as the “diaphragm” screw (https://lelandindustries.com/productpdfs/page%2001.pdf) this 1-1/2” part features a larger diameter shank than standard screws. A side benefit of this screw is that the larger diameter helps prevent the screw heads from twisting off during installation.

To this day, these screws remain a stable part of my building design, and have rarely (if at all) has this great improvement been equaled by any other pole building company.

Stay tuned for the final episode of “From Cradle to now…Mike the Pole Barn Guru” as he expands from four states…to fifty!