Tag Archives: steel trusses

Helping a Student with His Post Frame Thesis

Post frame buildings are becoming more relevant as a design solution for residential construction. I recently was contacted to assist a student and will let him tell his story:

mr owl tootsie roll pop“My name is George xxxxxx, I am currently a thesis student at Auburn University’s Rural Studio, located in Hale County, Alabama. I am looking into pole barn // post frame construction as a method for quickly building strong homes. Hansen seems like it has more experience in this methodology than most in the nation, where most contractors are afraid of diverging from traditional stick-frame construction. I am particularly interested in the structuring of your residential homes (the retirement home in Decatur is beautiful), and your opinion on steel vs. wood roof framing. If there is an expert who would be willing to spend some minutes this week answering a few of my questions it would be greatly appreciated! Also, if you have more questions about the Rural Studio I would be happy to answer them to the best of my ability.”


Being all about education and post frame, my answer was to the affirmative and here are George’s questions and their answers:

“We have seen a lot of other builders using steel trusses for both residential and commercial applications, however, your portfolio shows a large number of projects using wood trusses spaced significantly further than the typical 2′-4′ you see in stick frame. 

 

  • 1. When do you make the decision to go wood over steel?
  • 2. In relation to residential projects, is one more advantageous than the other in terms of detailing, cost or time?
  • 3, What kinds of applications do you use the 12’+ spacing, is it something you would employ for a small home? 
  • 4. What are your typical dimensions of wood posts?
  • 5. What are your standard dimensions between posts?
  • 6. Do you use girts or studwalls in the framing of residential post frame construction?
  • 7. Does using girts provide greater lateral stability?
  • 8. Why, in your opinion, has residential construction been dominated by stick frame construction, while post frame is a viable alternative?”

 

Mike the Pole Barn Guru responds:

1) We use wood over steel trusses 100% of the time.

2) Prefabricated wood roof trusses are highly engineered products subject to intensive quality control standards. Every truss is fabricated from engineer sealed drawings with design wind and snow loads specific to the jobsite upon where trusses will be used. Each manufacturer must keep a log of all trusses produced and any deviation from sealed drawings (higher grades of lumber used, larger pressed steel connector plates, etc.). Every truss must be stamped with appropriate information about it as well as the fabricator’s name and location. Prefabricated metal connector plated wood trusses are also subjected to random quarterly inspections from a third party provider – and one does not want to ever fail an inspection. Most steel trusses used for post frame construction are not engineered, not fabricated by certified welders and face none of these quality control standards wood trusses are required to have. For these reasons, most of them get used in jurisdictions with either no permits required, or no structural plan checks or field inspections.

Even with today’s record high lumber prices, prefabricated metal connector plated wood trusses still compare favorably in investment to steel trusses. Wood trusses are not conductors of heat and cold, as are steel trusses, meaning they do not need to be thermally isolated from climate controlled areas as steel trusses should be. Wood trusses are very user friendly in attachment of other wood framing members.

3) More often than not a 12 foot on center column spacing is most economical in use of materials and labor. Our Instant Pricing system allows for rapid checking of various column spacings in order to determine a most efficient spacing for any given set of loading conditions. Wider truss spacing means fewer column holes to dig and less worry about trying to place openings (doors and windows) to avoid column locations.

4) In solid sawn columns 4×6 (3-1/2″ x 5-1/2″), 6×6 (5-1/2″ x 5-1/2″) and 6×8 (5-1/2″ x 7-1/2″). In glulaminated columns 3 ply 2×6 (4-1/8″ x 5-3/8″). 4 ply 2×6 (5-1/2″ x 5-3/8″) and 3 ply 2×8 (4-1/8″ x 7-1/8″) are most common.

5) With 12′ on center columns and 6×6 columns space between columns would be 11′ 6-1/2″ as an example.

6) We use bookshelf style inset girts (https://www.hansenpolebuildings.com/2011/09/commercial-girts-what-are-they/) for most applications as they require no additional framing in order to be drywall ready. They happen to lend themselves to a better finished drywall surface than studwalls (https://www.hansenpolebuildings.com/2019/09/11-reasons-post-frame-commercial-girted-walls-are-best-for-drywall/).

7) Lateral stability of any framed structure (stick or post) comes from shear strength of siding – whether wood sheathing such as OSB or plywood, T1-11 or steel.

8) Stick frame has been around longer and Building Codes (especially IRC – International Residential Code) have embraced stick frame by providing a ‘cook book’ for it. Post frame construction just happens to be more economical in terms of foundation costs, use less wood, have fewer thermal transfer points, can easily be built DIY and can be customized far more economically than stick frame.

More than anything, lack of familiarity (by buying public, lenders, building officials and contractors) with post frame as a viable alternative to stick frame. Our team at Hansen Pole Buildings is doing our best to provide educational resources to all interested parties to make a change.

Miracle Truss Concerns

One of the great things about being the Pole Barn Guru is helping people who have construction challenges of all sorts – even those who do not have post frame buildings.

Here is a recent one:

Hi Pole Barn Guru, and thanks for your informative website and blog. I’m using email rather than the website question portal so I can include pictures. I’m a contractor, but my normal specialty is finish carpentry. I wouldn’t normally take on a pole building job, but this one is for my father so I’m helping him build it to try to save some money.

We’ve acquired a 51 x 120 ft building package made by Miracle Truss, a company which is apparently out of business, hence the lack of manufacturer support. The building was purchased years ago by a businessman who never put it up and finally decided to donate it to a church for a write-off. Long story short it eventually made its way to us, still palletized as new, for an incredible savings. So off the bat I’ll apologize for not buying a product from you, as we already have one. But I’m hoping I can use your expertise and perhaps do business in the future.

In case you’re unfamiliar with Miracle Truss, their design uses open-web steel trusses with owner-provided wood purlins and girts. Clips are welded to trusses to receive wood members. The design gives the strength and span benefits of metal with some of the economy of locally sourced lumber. It seems like a good design, but we’re still only in the planning & groundwork stages. The package includes Metal Sales siding and roofing.

My question relates to the use of “splash planks” on a metal-sided building. I know the purpose of the splash or skirt board in typical construction, but I’m doubting its necessity in this particular design. As you can see in the attached pictures, their plans call for a treated 2×6 splash plank which is used as the outside form board when pouring footings, with anchor bolts pre-installed, and then simply left in place and attached to the sill purlin. This places the outside plane of the wall 1-1/2″ outside of the concrete footing. There’s nothing wrong with this design of course, I just wonder if it’s necessary. I’m considering eliminating the permanent mud board, removing the concrete forms and using the sill (bottom) purlin to attach both the flashing and sheet. The last picture is a quick drawing of what I have in mind.

This means I would have to form my foundation 1-1/2″ outside of the stock plans, but save me 340 LF of AWW 2×6. Any thoughts on eliminating the outside splash board?

I’m also trying to decide the dimensions of my footings. Each post will sit over a buried Sonotube pier with a Bigfoot base, which will bear the weight of the building. The footing is really just a concrete”tie beam” and provides a sill for the walls, without really bearing anything. The total thickness of the wall is 17.5″ at the posts (our posts are W12″ I-beam, plus 5.5″ girt.), but only 5.5″ in between posts. I could form a continuous 17.5″ footing over the top of the Sonotubes (my original plan), or form an offset 8″ w footing to match the outside of the wall. I also am not sure how to choose footing thickness, since it’s not bearing. No guidelines are given for foundation in the package instructions, since climate makes a big difference. We are in southern Alaska, our code frost depth is 4 ft, which is where the tubes will sit. But I’m not sure what the footings should be. Any comments?

Thanks again for any advice you can give. I really appreciate the resources you offer. KADIN in KENAI

Dear Kadin:

Thank you for your kind words. We strive to be informative and entertaining.

IMPORTANT DISCLAIMER: The response below is only in regards to the now defunct Miracle Truss which produced the building package you now own. The Miracle Truss brand name is now held by Spider Steel Buildings, LLC. The current Miracle Truss was formed in 2015 and has no connection with the prior company or its products. According to their attorney, Kevin R. Coan of Hinshaw & Culbertson LLP, the current Miracle Truss can and does provide the lumber package as part of its services. Find out more about the new Miracle Truss at https://miracletruss.com/.

My objections to the defunct Miracle Truss system has always been how does one go about finishing the inside of the building with the steel frames in the way and (very important to most) the having to source one’s own lumber which can end up in a sticker shock situation.

Your Miracle Truss building’s outside 2×6 splash plank is there for a reason, and should be used. The bottom of it is the point at which level grade is on the exterior of your building. If it is not present the steel base trim will probably end up in contact with the ground outside of your building – which will result in premature deterioration as it slowly rusts away.

As to your footings, the best advice I can give would be to contract with a registered professional engineer in your area who can do an analysis of the forces upon your building, wind load, snow load, seismic, exposure, et. al. Also the engineer will need to take into account the bearing capacity of the soils at your site.

Good luck and let me know how it all turns out!
Mike the Pole Barn Guru

How to Install Steel Screws on a Roof

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: How much does a cupola weight? Wondering if I would need a crane to lift it onto the roof. Thanks VANQUISHING IN VANCOUVER

DEAR VANQUISHING: The cupolas we typically provide are going to be more than manageable by hand, for most people. On my own building (which is very large), I have a 48 inch square cupola (also very large).  The universal base (which is installed first, by itself) weighs 29 pounds. In my own case, I have a cupola with glass sides, so it is slightly lighter, weighing in at 35 pounds. The louvered model weighs 60 pounds. The cupola roof, weighs 55 pounds and weathervane 13. Our most commonly supplied cupola is 24 inches square. Its universal base weighs 29 pounds, the louvered sides 18 pounds, roof 10 pounds and weathervane 5 pounds.

Mike the Pole Barn Guru

DEAR POLE BARN GURU: I’m constructing a pole barn using steel roof trusses with 2×6 roof purlins. The lumber is not very straight and my screws are missing about 10% of time. Not knowing what else to do, I have currently just left them in place. What is the right move for so many missed screws?

Thank you! GRINDING IN GATESVILLE

DEAR GRINDING: Some background for those who are not familiar with the construction of your type of building….

Although we do not utilize steel trusses for our buildings, there is nothing wrong with a steel truss which has been properly fabricated from drawings provided by a RDP (Registered Design Professional – architect or engineer).

Typically steel trusses have clips or angles welded onto them, to accept the roof purlins – which are installed on edge. If the columns are set plumb and the clips are al at the same locations from truss to truss, then a good share of the battle has been won before beginning.

To avoid roof leaks from misses there are some steps to take:

First – make sure the roof plane which is to be sheeted is square and the eave line is straight.

Second – To maintain straight screw lines and avoid roof leaks, stack roof steel in a pile, mark screw locations (we’ve found a “dry erase white board” marker works well) and pre-drill steel sheets with a lesser diameter drill bit than the screws. For best results, drill no more than four sheets at a time. Be sure to use a soft cloth to wipe off the steel shavings that develop from putting in the holes with a drill and wipe off the marker lines before installing the panels.

Third – Distance from roof framing edge to first roof steel sheet edge is to be consistent from top to bottom. If NOT and your end wall is not properly aligned, straighten before roof steel can be properly applied.

Fourth – Keep panels from stretching or compressing in width as they are installed. Panels cover 36” from major rib center on one panel side to major rib center at other side of panel. Measure each panel as installing or pre-mark building frame (or underlying insulation) every 36” to check panel width.

As roof steel panels were predrilled, if screws miss a purlin, remove the screws which missed purlins, plus screws within three or four feet of each side of miss (along the same purlin). From inside of the building, have someone push the offending purlin either “uphill” or “downhill” until screw(s) can be driven through each hole into that purlin.

If a “random miss” occurs, the repair is to have someone hold a wood block underneath hole and drive a screw through hole into block. This is the manufacturer’s only approved repair for a missed screw.

Do NOT, under any circumstance, attempt to fix a missed screw hole with caulking. It will be a temporary fix at best and you will end up with leaks over time.

If the panels were not predrilled, you could have some issues which just cannot be fixed and the only solution may be to replace the roof steel and try it all again.

Good Luck!

Mike the Pole Barn Guru

Dear Pole Barn Guru: Wood or Steel Trusses?

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: Should I go with wood, or 12 or 14 gauge steel trusses? DELIBERATING DEE

DEAR DELIBERATING: I came from the prefabricated wood roof truss industry, having spent nearly two decades either having built them myself, been a designer, managing or owning roof truss manufacturing plants.

 In my experience I learned prefabricated wood trusses are amazing products. Not only can they be utilized for a myriad of different application, they also are a highly engineered product. Every component of a wood roof truss is put through a rigorous computer analysis, which verifies all members are capable (when properly installed and braced) to be able to withstand not only the snow loads to which they will be subjected, but also wind loads. The entire process is remarkably complex, involving the most up-to-date research available. Because of this, wood roof trusses just do not experience failures, within the parameters of the design loads.

 Besides all of this, pre-fabricated roof truss manufacturers are required, by the Building Codes, to be inspected quarterly by an independent firm for quality control. These inspections are done without any advance notice – the inspector just shows up unannounced. The truss company must supply the engineer sealed drawings for every truss the inspector wants to review. No engineering and the trusses must be destroyed. The inspectors are so thorough, they even take a micrometer to the steel roof truss plates, to confirm they are the correct thickness! The size and grade of every piece of wood in the truss is verified to meet or exceed what is specified on the drawings, and all of the joints between the wood members are checked to make sure they are tight. Even the placement of the steel plates must match what is shown on the drawings.

 The inspector also looks to make sure completed trusses are adequately stored to prevent deterioration of the wood members and to prevent damage to the truss plates.

 In other words, the inspections are rigorous.

 When I owned my first business, in Oregon, we hired a very nice gentleman to be a pole building sales person for us. Originally from Arkansas, Stan’s father built light gauge steel truss frames for “pole” buildings (in their case, the entire structural framework was made of steel, so they actually were not pole buildings – but rather light gauge steel frame buildings).

 Stan discussed with me his interest in building the same type of frames and distributing them in the Pacific Northwest. While I didn’t see this as a fit for our particular niche (we were pole buildings only), I did give Stan my blessings to head out on his own and start his own business.

 Apparently things were a little different where Stan was from – the steel truss frames there were made of steel angle iron for the top and bottom chords, and rebar was welded in between for the internal webbing. Engineering was never a requirement, Stan’s daddy just built them using seat-of-the pants – with the assumption if they worked in the past, then they would work in the future.

 The Pacific Northwest was not quite the same as Arkansas, as Stan quickly found out. In order to acquire building permits (required on most uildings in the West), Building Departments required engineer sealed drawings for the steel truss frames. Having to engineer the trusses resulted in upgrades to the designs – no more rebar for truss webs, they had to use angle iron there as well. Plus, it required certified welders having to do the fabrication. These requirements added exponentially to the cost of the frames, and made them have to play by rules similar to the prefabricated wood roof truss industry.

Stan long ago sold his interest in the company he founded, but it continues to fill a place in the market. The buildings are generally 15-20% more than post frame construction.

 As to the choice of trusses, most people are very comfortable working with wood as wood tends to be very forgiving. Attaching wood roof purlins to a steel framework is not as easy or straightforward as wood to wood.

 Part of the answer to your question is – what is it going to cost? In order to get a direct comparison, make sure the proposed light gauge steel trusses being quoted come with wet sealed (not photo copied) structural drawings. The drawings should also include the requirements for bracing. Steel trusses normally take diagonal steel struts from the bottom chord of the truss, up to the roof purlins, to prevent buckling of the trusses in the weak direction. The bracing, as well as any connectors should be included in the price. Detailed instructions should be provided so the trusses are adequately attached to the columns, and for installation of the bracing.

DEAR POLE BARN GURU: Do you have someone to install your buildings? TEXAS JEFF

DEAR TEXAS: Hansen Pole Buildings is a supplier of pole building kit packages only.

 You do not need to hire a contractor to build your pole building. Our buildings are designed for the do-it-yourself person. Most of our clients do their own construction. We believe our drawings and industry-leading Construction Guide are clear enough to make the task relatively simple, even for the first-time builder. Keep in mind this is a material kit, not a completely pre-fabricated structure. Assembly, including measuring and cutting, will be required. You will be required to have (or borrow or rent) various hand tools. If you are not comfortable with putting up your own building, a contractor should be available at a reasonable price. We have found the average person who can read and understand English can, and will, build a better building for him or herself than most contractors. Why? Because it’s YOUR building and you will take the time and care to do it “right”.                                                                                  

We are clearly not contractors in any sense of the word. We do not construct, build or repair buildings (or portions of buildings) anywhere for anyone. Should you need a builder, we DO have a list of builders for nearly anywhere in the country. Please call our office to receive a builder referral.

 Keep in mind, a referral is not an endorsement on Hansen Pole Buildings part of the particular builder’s skills or lack thereof, As none of them work directly for us, we can’t guarantee the quality of their work, We DO have a “one strike and you’re out” rule for our referral list. Simply, if we receive even one verifiable and legitimate negative complaint about any particular builder, we will no longer give out their name to our clients. While this is not a fail-safe method, it does afford some degree of protection, it is always a good idea to speak with other customers the builder has done work for in the past, to get an idea of the builder’s professionalism.