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Tornado Safety, Garage Additions, and Utilities in Post Frame

Following the severe weather of this morning (Monday June 29th) across the Dakotas, we thought a repost of the question about the safety of post frame in a tornado would be appropriate.

This week the Pole Barn Guru answers reader questions about the safety of a pole barn in the event of a tornado, whether a new post frame garage can be added to an existing home, and the standards to run utility wires and pipes through posts.

DEAR POLE BARN GURU: How safe are pole barn houses in tornadoes? BRENDA in CHATTANOOGA

DEAR BRENDA: Fully engineered post frame (pole barn) houses are as safe and sturdy as their design wind speeds. We can have your building engineered to resist wind speeds up to and in excess of 200 miles per hour (basically encompassing EF4 events). In weighing out risk/reward – a Hansen Pole Buildings’ Designer can price for you incrementally starting at your jurisdiction’s mandated design wind speeds. This allows you to determine what you are willing and able to invest.

DEAR POLE BARN GURU: Is it possible to design a 2 car garage to attach directly to the side of my house with matching vinyl siding? AMY in CLEVELAND

DEAR AMY: Yes it would be possible. We would need to have information on (dimensions and location of attachment) and photos of your house as well as what brand and color your vinyl siding is.

DEAR POLE BARN GURU: Good morning sir, I am building a shop/house and have a question about running wire and pex water lines through the posts I have read your threads about this yet still not 100%. I do not have the gap between the metal and the posts like you spoke of so drilling the posts seems like the easiest way for me to accomplish the routing of the wire. So what is the right answer, can i drill the posts or not per code?? Thanks SAM in KENNEWICK

DEAR SAM: Think of a hole being drilled through as being an “open knot”. Lumber grading rules refer to these as being “Unsound or Loose Knots and Holes” due to any cause. Most structural framing – like wall girts and roof purlins or posts and timbers are graded as Number 2.
For practical purposes, a hole up to just less than ¼ of board face being drilled through will be within grade in #2 lumber. Example: 5-1/2” face of a 6×6 a hole up to 1-1/4” may be drilled through, as often as every two feet. Allowable hole sizes are reduced and spacing increased for higher grades of lumber.

This entry was posted in Building Styles and Designs, Constructing a Pole Building, Pole Building How To Guides, Pole Barn Planning, Pole Barn Structure, Pole Building Siding, Vinyl Siding, Columns, Pole Barn Questions, Post Frame Home, Pole Barn Design and tagged post frame addition, tornado safety, EF4 wind, water lines, post frame wiring, post frame water pipes, wind speed, alternative siding on July 1, 2026 by Rick Ochs.

Who is Responsible for Verifying Design Loads?

Who is Responsible for Verifying Design Loads by Contract?

Disclaimer – this and subsequent articles on this subject are not intended to be legal advice, merely an example for discussions between you and your legal advisor.

Please keep in mind, many of these terms are applicable towards post frame building kits and would require edits for cases where a builder is providing erection services or materials and labor.

DESIGN LOADS/CONDITIONS: Plan, drafting, engineering or calculation changes needed due to Purchaser’s failure to adequately confirm criteria in this section, or Purchaser’s desire to change building dimensions or features, will result in a minimum $xxx charge.

It is solely upon Purchaser to verify with Purchaser’s Planning and/or Building Departments, or any other appropriate government, or non-governmental agencies, the ability to construct purchased building(s) at location anticipated, as well as to apply for and obtain any needed permits. All due diligence to comply with any architectural or aesthetic covenants must be done by Purchaser, and Purchaser agrees to absorb any costs associated with compliance.

Purchaser acknowledges verification/confirmation/acceptance of all Building Code, Plan and Design Criteria included on Instant Invoice. Information Purchaser has verified includes, but is not limited to: Applicable Building Code version, Occupancy Category, Ground (Pg) and Flat Roof (Pf) Snow Loads, Roof Snow Exposure Factor (Ce), Thermal Factor (Ct), Wind Speed (vult or 3 second gust) and Wind Exposure, Allowable Foundation Pressure, Seismic Zone and Maximum Frost Depth, as well as obtaining for Seller any unusual code interpretations or amendments.

Seller’s designs are all per specified Building Code and include the use of NDS Table 2.3.2 Load Duration Factors (Cd) as well as ASCE 7, Eq. 7-2 for slippery surfaces. Seller’s designs rely solely upon occupancy category and structural criteria for and at specified job site address only, which have been provided and/or verified by Purchaser.

It is Purchaser’s and only Purchaser’s responsibility to ascertain the design loads utilized in this Agreement meet or exceed the actual dead loads imposed on the structure and the live loads imposed by the local building code or historical climactic records. Purchaser understands Seller and/or third party engineer(s) or agents will NOT be contacting anyone to confirm.

Dead loads specified on engineered roof truss drawings include the weight of the roof truss. Roof trusses are NOT designed to support ANY hanging loads or ceiling loads other than those specified as special truss loads in the Agreement. In the case of design roof truss bottom chord loads of less than five (5) psf (pounds per square foot) the bottom chord dead load may be sufficient only to cover the truss weight itself and may not allow for any additional load to be added to the bottom chord.

Roof truss top chord design loads of 5 psf (or less) are not adequate for roofing other than light gauge steel.

Seller recommends use of A1V (aluminum/single air cell/vinyl) radiant reflective barrier, an Integral Condensation Control (I.C.C. – Dripstop, Condenstop or similar), solid sheathing (with appropriate underlayment) or Purchaser applied 2″ or thicker closed cell spray foam insulation to help control roof condensation.

In no case is Seller liable for any condensation issues. An I.C.C., when ordered, is manufacturer applied to roof steel panels only. Seller makes no representation of any R or U value for any insulation or insulation products supplied. In the event Purchaser opts to utilize snow loads, wind loads, wind exposure factors, seismic loads or ventilation of less than those recommended by Seller, or soil bearing capacities greater than those recommended by Seller, Seller and third party engineer(s) are totally absolved of any and all structural responsibility.

Any windows and/or doors provided by Seller are NOT wind-rated, unless specifically noted as such.

Any possible design responsibility for this building is null and void should any structural materials and/or construction be substituted, replaced, depart, deviate, or are otherwise altered from the Seller’s original building kit they belong to, including structural materials from suppliers not authorized in writing by Seller’s owner, or if building is constructed at an address other than as specified on plans.

This entry was posted in Pole Barn Design, Building Department, Pole Barn Planning, Professional Engineer and tagged thermal factor, flat roof snowload, seismic zone, engineering changes, design criteria, calculation changes, design loads, roof snow exposure factor, wind exposure, allowable Foundation, ground snow load, maximum frost depth, occupancy category, wind speed on June 10, 2025 by Rick Ochs.

a BONUS PBG for Monday, May 27th — Store Front Windows, Tornados, and Texas

a BONUS PBG for Monday, May 27th — Store Front Windows, Tornados, and Texas

DEAR POLE BARN GURU: I have a customer who is going to have 2×8 and 4×8 store front windows. These window frames need to be as close to the ground as possible. How do I need to build the bottom of the frame for these windows? Thanks JOHN

DEAR JOHN: You could cut out 2x pressure preservative treated splash plank to 1-1/2″ above top of slab (top of pressure treated bottom plate) and rest windows directly on top of bottom plate. This would place windows 1-1/2″ above top of slab.

DEAR POLE BARN GURU: It is tornado season again in mid-America and it reminds me to inquire about how best to be survive when up to 150MPH winds hit my ‘prospective’ post-frame house with on-grade slab. What sort of ‘solution’ does the Guru recommend for the SW corner of the house? Here in Zone 6, traditional houses have a concrete basement and include at least a section of reinforced concrete to provide a ‘safe zone.’ Newer houses built on a slab include a reinforced concrete ‘cave’ inside the house which may also be a utilities room. Thanks for any insights you must have since you also know about tornadoes hitting close to home. BRIAN in LE ROY

DEAR BRIAN: A couple of considerations – first, we can engineer your post-frame home to design wind speeds of 150, 170 or even 200 mph. In most instances, especially with single story buildings, added investments are minimal. Second, there are numerous affordable prefab units (easiest found with a Google search) easily incorporated into any structure.

DEAR POLE BARN GURU: Do you build in the state of Texas. DOUGLAS in MIDLAND

Dear Douglas: Thank you for your interest in a new Hansen Pole Building. While we have provided a plethora of fully engineered post-frame buildings to our clients in Texas, we are not building contractors in any state. Our clients have most built DIY, or hired an erector.

This entry was posted in Building Drainage, Budget, Professional Engineer, Pole Barn Questions, Pole Barn Design, Pole Barn Homes, Building Department, Post Frame Home, Pole Barn Planning, Barndominium, Pole Barn Structure, Windows and tagged Windows, window height, wind speed, tornado, texas, tornado safety, post frame window opening on May 27, 2024 by Rick Ochs.

San Diego County, Wind Speeds, and Wet Set Column Brackets

This Wednesday the Pole Barn Guru answers reader questions about whether or not Hansen has sold a building in San Diego County, CA, a building with a design wind speed of 150mph, and a recommendation for use of PermaColumn wet set brackets.

DEAR POLE BARN GURU: Have you sold pole barns in San Diego County, CA? KEN in RAMONA

DEAR KEN: It is a challenge to find any county in America without a Hansen Pole Building (or several) in it. We have provided close to two hundred fully engineered post frame buildings to our clients in California – including in San Diego County.

DEAR POLE BARN GURU: Hello, Our codes recently changed to 150 mph plus for wind load and I want to build a post frame home. Do you have engineering to satisfy that for any pole barn kit/trusses/etc that you may offer for sale? I’ve attached a file and have the spacing showing in red squares as 10 ft-10 ft-8 ft-10ft-10ft. Thanks. JEFF in MARIANN

DEAR JEFF: Thank you for your interest in a new Hansen Pole Building. We are able to engineer for design wind speeds in excess of 200 mph. One of our Building Designers will be reaching out to you shortly, or call 1.866.200.9657 for immediate assistance.

DEAR POLE BARN GURU: Hello Mr. Mike. I have attached our plans and had a couple questions. What do you think about perma column brackets for this type of build? What do you think about our plans in general? Any issues? We are building in south Georgia. Thank you so much. JASON & ERIN in THOMASVILLE

DEAR JASON & ERIN: Your plans did not arrive as an attachment, so I am unable to speak to them. If your concern is with properly pressure preservative columns prematurely decaying when embedded in ground, then Permacolumn Sturdi-Wall Plus brackets are indeed your best design solution. Unlike other, cheaper, brackets, these actually will resist moment (bending) forces and have ICC-ESR approvals as being Building Code conforming. For extended reading on Sturdi-Wall Plus brackets: https://www.hansenpolebuildings.com/2019/05/sturdi-wall-plus-concrete-brackets/

Please forward your building plans, site address and best contact number to Caleb@HansenPoleBuildings.com, as our team can evaluate them for practicality as well as providing a firm price quote.

This entry was posted in Concrete, Footings, floorplans, Professional Engineer, Columns, Pole Barn Questions, Pole Barn Design, Pole Building How To Guides, Pole Barn holes, Pole Barn Planning, Barndominium and tagged permacolumn, wind loads, San Diego County, Engineered buildings, wind speed, Post brackets, wet set brackets, hansen locations on February 28, 2024 by admin.

Termite Barriers and Wind Speed, Hidden Fasteners, and Truss Modifications

This week the Pole Barn Guru tackles reader questions about termites that can destroy treated lumber in an area wind 80mph winds, if one can install a roof with hidden fasteners over trusses or if it needs an underlayment, and the possibility of modifying a truss chord in order to accommodate a overhead door operator.

DEAR POLE BARN GURU: We have terrible subterranean termites that can destroy treated lumber. We also live in an area that sees 80 mph winds in the winter. Are your pole barns strong enough to withstand these things? DAN in FRAZIER PARK

DEAR DAN: Every Hansen Pole Building is fully engineered to meet or exceed your jurisdiction’s minimum design wind speed requirements (in Ventura county Vult = 100 mph). When wind is a client concern, we always recommend designing to higher than minimum design wind speeds. In many instances, added investments are minimal. Most important is designing to correct wind exposure for your particular site. Most other providers sell Exposure B rated buildings, when many sites are actually Exposure C. For extended reading on wind exposure, please read: https://www.hansenpolebuildings.com/2022/06/wind-exposure-and-confusion-part-iii/ While our buildings come with any pressure preservative treated wood at or above Building Code requirements. Regardless of structural building system in areas prone to subterranean termites treat prepared soil with a termiticide barrier at a rate of one gallon of chemical solution per every 10 square feet.

DEAR POLE BARN GURU: I want hidden fastener steel roof, do I need to sheath the roof or can I install over trusses. Also, how far apart are your trusses for residential pole barn homes? JAY in MILWAUKEE

DEAR JAY: Hidden fastener steel should only be installed over solid sheathing as it has no shear value to be able to transfer wind loads from roof to endwalls. https://www.hansenpolebuildings.com/2015/08/standing-seam-steel/

In most instances, our fully engineered post-frame barndominiums are designed with a pair of trusses directly aligned with columns every 12 feet.

DEAR POLE BARN GURU: Would it be possible to install a 1/8- 1/4 ‘’ steel plate C-shaped with a “tail” extending from back side to tie a bottom chord and king post together and then cut out a 6’’ section to allow for a garage door opener install. GABE in SIMCOE

DEAR GABE: Maybe, however no truss should ever be cut or modified unless done with an engineer certified repair. https://www.hansenpolebuildings.com/2016/07/cutting-trusses/

This entry was posted in Footings, Rebuilding Structures, Building Interior, Budget, Lumber, Columns, Pole Barn Questions, Fasteners, Pole Barn Design, Roofing Materials, Pole Barn Planning, Pole Barn Homes, Pole Barn Structure, Trusses and tagged termites, Vult wind speed, ACQ treated lumber, standing seam roofing, hidden fasteners, truss modification, wind speed, treated columns, osb under steel on October 4, 2023 by admin.

Exactly Identical and 20% Less

There is always someone willing to sacrifice quality and/or service to get to a lower price. I have seen it over and over again for decades now.

Price shoppers, or deal hunters, seem to be most interested in the lowest price. Unlike value shoppers who are willing to pay more in favor of an increased sense of value, deal hunters will only pay less and are willing to accept less.

I had an interaction recently with a potential client from rural North Dakota, who is looking to invest in a new post-frame building for a garage/shop. He had received a quote for a similar dimension building from a large vendor who advertises they will save customers big money and their price was quite a bit lower.

In my humble opinion, this client really wanted to do business with us – he was a value shopper, not a price shopper. He did offer to share his quote with me and I found it to be interesting, as it was a multi-page list of materials, rather than stating possibly important things such as building dimensions, design loads, etc.

My goal has always been to assist clients to help them avoid making choices they will regret forever.

Below is my response to this client:

Thank you for your patience while I have gone through xxxx quote. Here are some things I noticed:

xxxx building is not engineered and there is no stated design wind speed or exposure, both of which are critical for adequate structural design.

xxxx is furnishing nailed up columns, with 22′ ones being spliced. I did destructive testing of steel plate reinforced nail-lam columns at Oregon State University. Didn’t work out as well as I had hoped – as the center member takes twice as much load as outer plies (due to nails from both sides going into center member) and failed every time.

They do not furnish posts for either side of entry doors

Their quote included OSB under roof steel, however screws do not hold in OSB and a 1″ screw would penetrate only 1/2″ into blocking between trusses, if added.

Their quote did not include wall OSB or housewrap.

Entry doors – builder grade, primed only, in wood jambs, as opposed to insulated commercial steel, in steel jambs, factory finish painted.

We used to buy overhead doors from Clopay (parent company of Ideal). Ideal doors typically have very low cycle springs and use nylon hinges as opposed to steel.

Our buildings utilize double trusses aligned with interior sidewall columns, to avoid the possibility of a single truss failing and pulling the balance of the roof down with it.

Ventilation should be intake at eaves, exhaust at ridge for best airflow. Endwall soffits should be non-vented and there should be no gable vents.

There is no Z trim on xxxx quote between wainscot and steel panels above.

Delivery not included from xxxx.

Attached quote is how I would want my own building…..

Commercial wall girts for insulation (2×8 on eave sidewalls), framing is included to be drywall ready. https://www.hansenpolebuildings.com/2019/09/11-reasons-post-frame-commercial-girted-walls-are-best-for-drywall/

Trusses with raised heels, so ceiling insulation will be full depth from wall-to-wall https://www.hansenpolebuildings.com/2012/07/raised-heel-trusses/

Raised panel (not industrial looking ones xxxx quoted) insulated WIND-RATED overhead doors https://www.hansenpolebuildings.com/2014/12/wind-load-rated-garage-doors/

Roof steel with an Integral Condensation Control https://www.hansenpolebuildings.com/2020/09/integral-condensation-control-2/

Besides fully engineered plans, showing location and connection of every component, you get our 500+ page step-by-step construction manual and unlimited free technical support from people who have actually built post frame buildings.

Will this potential client actually order his new building from Hansen Pole Buildings? There is a distinct possibility and if his choice is to invest elsewhere, at least he has hopefully gained enough insight to make an informed decision.

This entry was posted in Pole Barn Questions, Constructing a Pole Building, Pole Barn Planning, Pole Barn Structure, Building Contractor, Trusses, Budget, Insulation and tagged wind speed, OSB, Post-Frame, insulated steel entry doors, commercial wall girts, wind exposure, nail-lam columns, house wrap on June 13, 2023 by admin.

Tornado Safety, Garage Additions, and Utilities in Post Frame

This week the Pole Barn Guru answers reader questions about the safety of a pole barn in the event of a tornado, whether a new post frame garage can be added to an existing home, and the standards to run utility wires and pipes through posts.

DEAR POLE BARN GURU: How safe are pole barn houses in tornadoes? BRENDA in CHATTANOOGA

DEAR POLE BARN GURU: Is it possible to design a 2 car garage to attach directly to the side of my house with matching vinyl siding? AMY in CLEVELAND

DEAR AMY: Yes it would be possible. We would need to have information on (dimensions and location of attachment) and photos of your house as well as what brand and color your vinyl siding is.

This entry was posted in Pole Barn Questions, Post Frame Home, Pole Barn Design, Building Styles and Designs, Constructing a Pole Building, Pole Building How To Guides, Pole Barn Planning, Pole Barn Structure, Pole Building Siding, Vinyl Siding, Columns and tagged wind speed, alternative siding, post frame addition, tornado safety, EF4 wind, water lines, post frame wiring, post frame water pipes on May 3, 2023 by admin.

Stud Walls Between Post-Frame Columns for Alternative Sidings

Stud Walls Between Post-Frame Columns for Alternative Sidings?

Reader JAKE brings up an interesting question:

“Hello! I was looking at the blog for a question I had about wall girts for post frame buildings… I was wondering that if a form of siding is installed on the building other than sheet metal, needing wall sheathing, would it be structurally sound to frame 2×6 walls between your 12’ apart posts and not have wall girts? Just attaching the wall sheathing to the posts and 2×6 walls in between? Thank you!”

Mike the Pole Barn Guru says:
Before we get to your structural question, a few words. 6×6 columns are notorious for having dimensional variability. I have seen them run as much as 3/4″ over dimension. An over 5-1/2 inch dimension would mean your columns are going to project either inside or outside of your stick framed interior wall.

Now we get into structural soundness.

My concern is how to adequately transfer loads from the top of the stud wall into columns.

Walls lie within two wind zones. Zone 5 is within 10% of least building footprint dimension, with a minimum of four feet. It applies to any secondary member with over 50% of its length within this zone. Provided your building is 60 feet or less in length and width and bays are 12 foot, it would not be applicable for your case.

Wind pressure is derived from wind speed “V”. For an Exposure B (protected from wind in all four directions) site, here are applicable loads in psf (pounds per square foot) for secondary components and cladding members (with mean roof height less than or equal to 15 feet) and a fully enclosed building:

MPH PSF (ASD – Allowable Stress Design)

95 10.527

100 11.664

105 12.86

110 14.114

115 15.426

120 16.797

125 18.226

130 19.713

135 21.258

140 22.862

All of these loads are negative, meaning your wall is trying to be sucked out of your building.

Arbitrarily picking 110 mph and a 10 foot wall height (if this is for a residence, or accessory building to a residence, then wall heights are limited to 11’7″ by IRC – International Residential Code Section R301.3):

Total load on a 12′ section of wall (by length) would be: 12′ x 10′ tall x 14.114 psf = 1693.68#. One half of this load is transferred to ground through bottom plate, and one half of remainder must be transferred through top plates to column or 423.42#.

When not nailed into end grain (through a plate into end of stud would be end grain and value is reduced x 0.67; toe-nailing reduces value x 0.83) a 10d common nail (3″ long x 0.148″ diameter) nail has a laterally loaded strength value of 102.022# with Hem-Fir or SPF lumber.

How to attach the wall section to the column is your challenge.

In order to nail through end stud into columns, connection at top of stud (nail driven through top plate) would take 423.42# / (102.022# x 0.67) = 6.19 nails. Probably unrealistic to expect to drive 7 nails into top of a single 2×6 stud.

How about toe-nailing plates to column? 423.42# / (102.022# x 0.83) = 5 nails. While ugly, this might be doable.

Ultimately, connection of top plates to columns would probably be cleanest by use of a Simpson Strongtie strap such an LSTA12.

For our example I have picked a fairly low design wind speed, so higher wind speeds will increase loads and make connections even more difficult. As building mean eave height increases beyond 15 feet, applied loads will increase. In order to meet enclosed building requirements – plan upon use of wind load rated doors (other criteria also apply to meet enclosed requirements), else applied loads may increase. Don’t have a protected site? Exposure C places a load approximately 20% greater than Exposure B on your building.

In summary, while what you propose might work, it should be checked by whatever engineer is placing his or her stamp on your building plans.

This entry was posted in Uncategorized, Pole Barn Questions, Pole Barn Planning and tagged stick framed construction, wall girts, wind speed, wind exposure B, wall sheathing, cladding members on March 23, 2023 by admin.

Answers to Questions Unable to Find on Website

Answers to Questions Unable to Find on Website or Learning Info

Even having penned over 2000 articles on post-frame design, there are always more topics to cover and questions to be answered. Luckily, we have potential clients who want to know – as informed clients are happy clients!

Reader CARY in RAYMOND writes:

“Raymond Nebraska, Exposure C (in Tornado Alley), monitor style pole barn (30’ wide x 40’ deep x 18’high with 2 16’ wide x 40’ deep x 10’ high sidewalls.

We have sustained winds of 30 to 45 mph and gusts from 60 to 75 mph during storms. Our new house lost 1/3 of its roof During tornado event in 2013 and insurance agent stated 160 mph winds in our area. For this reason, I want a very sturdy structure to minimize damage should another tornado pass by. Wind driven snow and drifts are a problem as well although this past winter not too much snow.

I wish to retain a monitor style building and it appears a gambrel roof style would be your preferred scheme to minimize wind wall loading if I read your info and blog correctly. Is there a preferred ratio of slanted side to top panel roof for a gambrel style? If so your ideas. Diaphragm design, working storm design, tornado straps, etc., to mitigate damage.

Max load duration of 10 minutes per lifetime?? I understand that wind does not sustain high speeds usually however buffeting can be quite severe. How does one account for this in this calculation? Just an answer a layman might comprehend, I am not an engineer, but 10 minutes over the lifetime of the building.

The double truss design piqued my interest yet the attachment to the columns has me baffled. If I recall Kyle from Rural Renovators uses your laminated columns and trusses and wet sets. The upper portion of the 3 ply column is constructed minus a portion the middle 2×6/2×8 to allow truss with 15 1/2” heel to fit. With a doubled truss would this design require a 4 ply column or how would it be done / connected?

What is the strongest way to mount a column for a pole barn? Buried 4 feet in concrete (frost line here 39”), wet sets placed in a footing to frost line, constrained by concrete on all sides ( 4’ sidewalk around building ) negating hairpin. On this subject what is the plastic sleeve I believe I read about on your site, extra protection against rot?

Thank you for your time to answer these questions and I shall forward line drawings of my project once I understand these issues. I have gone to many sites and yours is most helpful.”

Mike the Pole Barn Guru’s answers:
Code design wind speed in your area is 115 mph (just an FYI). For Exposure C sites, effectively buildings must resist roughly 20% greater forces than Exposure B at the same design wind speed.

1) Monitor style with a gabled roof would minimize effects of wind loads. Gambrel style roofline increase vertical dimensions, creating a greater surface horizontal wind forces are applied to. Our engineers verify every component and connection for adequacy to resist selected design wind speeds and exposure. Hansen Pole Buildings are designed utilizing diaphragm design.

2) Sound engineering practice for wood design incorporates a load duration of 10 minutes at design wind speed, across building’s lifetime. P (pressure) at a given wind speed is determined from speed (in mph) squared x .00256. For 115 mph, P = 33.856 psf (pounds per square foot). A 75 mph gust produces a force of only 14.4 psf (just over 40% of design load). For structural design of systems incorporating wood, we are only allowed to utilize design values of 40% of Pult (ultimate failure pressure). To paint a picture in layperson’s terms – if 100 samples of a given grade of lumber were tested to failure and their failures were plotted on a bell curve, we would go to 5th percentile failure from the bottom of the curve and utilize 40% of this failure’s value for design. This results in a tremendous safety factor for engineered wood design and explains why engineered wood structures, built to plan, do not fail within design loads.

3) Double trusses are notched into one side of columns, rather than having to have expensive lifting equipment to raise trusses up and over a central notch in a column. This allows for entire bays of roofs (two sets of trusses, with purlins and bracing in place) to be cranked up columns using winch boxes https://www.hansenpolebuildings.com/2019/11/winch-boxes-episode-v/

4) Properly constrained embedded columns are strongest method to resist wind loads. https://www.hansenpolebuildings.com/2018/11/importance-of-constrained-posts/. An external sidewalk would not provide constrainment, as there would be a joint created where splash plank divides two independent slabs. Although properly pressure preservative treated (UC-4B) columns will not experience premature decay within lifetimes of anyone alive on our planet today (https://www.hansenpolebuildings.com/2020/09/pressure-treated-post-frame-building-poles-rot/).

This entry was posted in Pole Barn Questions, Pole Barn Planning, Trusses, Concrete, Footings, Columns and tagged diaphragm design, tornado straps, double truss design, wet set brackets, plasti-sleeves, wind speed on February 21, 2023 by admin.

Who is Responsible for Verifying Design Loads?

Roof truss top chord design loads of 5 psf (or less) are not adequate for roofing other than light gauge steel.

Any windows and/or doors provided by Seller are NOT wind-rated, unless specifically noted as such.

This entry was posted in Professional Engineer, Pole Barn Design, Building Department, Pole Barn Planning and tagged ground snow load, maximum frost depth, occupancy category, wind speed, thermal factor, flat roof snowload, seismic zone, engineering changes, design criteria, calculation changes, design loads, roof snow exposure factor, wind exposure, allowable Foundation on July 9, 2021 by admin.

Tornadoes Reek Havoc

Tornadoes Reek Havoc, Don’t Let Them Wreck You
Excerpts in italics below are from an article first appearing in SBC Magazine June 3, 2019:
“In the past few weeks, weather systems throughout Texas, Oklahoma, Missouri, Indiana and Ohio have had a significant impact on the built environment. As is well known, tornadoes cause severe stress on buildings where the high localized wind loading conditions find the weak point of the structure quickly. This usually is at the location of a wood nail, wood connector or anchor bolt connection, or in our testing experience, a knot or slope of grain deviation in a lumber tension member. An interesting point is that most studs in wall systems are meant to see compression forces not tension, where studs in tension may also be a structural weak point.

As the pictures herein attest, finding the key building material weak point that caused the structural performance to be a debris field is challenging, if not impossible, to do.

Tornado damage in Jefferson City, Mo. as seen on Thursday, May 23, 2019. Photo by David Carson, St. Louis Post-Dispatch.

Questions that need to be sincerely addressed follow, which include but are certainly not limited to:
What were the as-built conditions?
Was the building built to code?
Which aspects of the structure were built to code?
Which aspects of the structure were not built to code?
What is the cause/effect analysis for each code compliant and each non-code compliant condition?

It is obvious that proper construction implementation is key to satisfactory building material performance. Paying close attention to all connecting systems that make up the load path is essential.

The most important outcomes of poor building performance in a high wind or seismic event are that no one gets hurt; the construction industry continues to learn and evolve; and design and installation best practices improve.

The entire construction industry can greatly benefit by staying focused on providing framer-friendly details that are easy to understand and implement. It’s critical that we come together with the goal of fostering innovation, using accepted engineering practice, creating installation best practices, working closely with professional framers and assisting building departments to focus inspections on key load path elements. We all are educators. By working together, we will significantly improve the built environment.”

Mike the Pole Barn Guru adds:
Readers will note, these failures are in stick frame construction. Certainly there were also pole barns failing in tornado areas as well, however it is my opinion post frame buildings, engineered to withstand appropriate wind speeds, and assembled according to engineering documents would survive these storms – preventing both loss of property and life.

Code requirements are merely minimum design standards and often do not address severity of real life events. My recommendation is when in doubt, design to higher loads than minimum, in most cases these higher design loads involve a nominal investment and your family and expensive possessions deserve this type of protection.

Talk with your Hansen Pole Buildings’ Designer today at 1(866)200-9657 to find out what a lifetime of protection will involve.

This entry was posted in Pole Barn Design, Building Department, Pole Barn Planning, Pole Barn Structure, Building Contractor and tagged post frame buildings, wind speed, SBC Magazine, framers, building departments, building code requirements, tornadoes on June 28, 2019 by admin.

Self-Designed Pole Buildings

Spring, When a Young Man’s Heart Turns to Self-Designing Pole Buildings

For some obscure reason a plethora of otherwise intelligent people have an idea. This idea being they can structurally design a building to be adequate to resist applied climactic loads, without any actually engineering background. Given an under designed building can lead to failure, injury and even death of occupants and/or bystanders, one might think it would be best left to professionals.

Reader NORM in SILVERTON writes:

“I’m considering building an open pavilion style pole building, with outside (the posts) dimensions of 20’ x 16’ x no more than 9’ to 10’ high posts, secured to cement pad with Simpson CC66 caps. There would be 3 posts on both the left and right sides, that would be 8’ from middle, of middle post, to outside edge of front and back post. The alignment of 3 posts on each side, would be 20’ apart with 6/12 gable roof, supported with roof trusses (50 PSI Snow Load). On each side, the roof overhang would be 3’, which I don’t think matters when considering my question. The posts are more than sufficient size and strength for the gabled metal roof ….. I’ve been told.

Question: What “wind gust” strength would I need to be concerned about from side to side, for the “sway” factor ? Would that “wind strength” be less if directly behind this “pavilion”, was a slightly larger and taller building, AND directly behind that building, was standing forest with trees that were 60’ to 100’ tall ? We obviously are NOT in tornado country like the Midwest and South.

Thank You.”

About Hansen Buildings Thank you for your interest in a new Hansen Pole Building. We should be able to take care of all of your needs with a third-party engineer sealed set of blueprints specifically for your building. Face it – this eliminates any guesswork, as anything you do without a Registered Design Professional involved is nothing but a W.A.G. (Wild Ass Guess), probably an errant one. Given height of your roof (it takes full brunt of wind coming from a side) it is unlikely a 6×6 column will work in bending (it is plenty strong enough to support downward forces from building weight and roof snow load acting alone).

Even without being an engineer I can tell you a proposed Simpson CB66 is totally inadequate. Frankly your ideal design solution is to embed your six columns into the ground and concrete them in to avoid uplift and overturning challenges. If you feel you must have columns above ground, then we can design using a proper wet set anchor capable of carrying imposed loads.

If your building is wind unprotected on even one side or end chances are it is Exposure C for wind design. You do not get credit for a building being protected on one side (or even two or three) by a larger taller building or a forest – only if it were to be entirely surrounded. (read more here about Wind Exposure: https://www.hansenpolebuildings.com/2012/03/wind-exposure-confusion/).

A Hansen Pole Buildings’ Designer will be reaching out to you to further discuss your proposed project, or dial 1 (866) 200-9657 and talk with one now!

This entry was posted in Pole Barn Design, Building Department, Pole Barn Planning, Pole Barn Structure, Concrete, Professional Engineer, Columns, Pole Barn Questions, Pole Barn holes and tagged wind exposure C, wind uplift, wet set anchors, design wind speed, registered design professional, wind speed on May 17, 2019 by admin.

A Tornado and a Pole Barn

Pole Barns and Tornados

(Excerpts from a July 21, 2018 Jeffersonville, Indiana News and Tribune article by Jenna Esarey are incorporated in this article)

“NEW MIDDLETOWN — With Bobcats, ATVs and chainsaws, many residents of New Middletown spent their Saturday cleaning up after an EF-1 tornado cut a swath through homes, barns and cornfields Friday afternoon.

The National Weather Service on Saturday confirmed that an EF-1 tornado, with winds of 105 miles per hour, hit the small community just southwest of Corydon in Harrison County around 2:16 Friday afternoon.

The worst of the damage was near New Middletown, though. Homes along Simler Road were buffeted by the tornado, however, most structural damage was to out buildings.

Just down the road, Danny Perry’s farm was severely damaged.

“I lost my barn, back side of my pole barn, the back of my roof and all of my fruit trees,” Danny Perry said.”

2018 International Building Code (IBC) shows for Indiana in Section 1609.3 a basic wind speed (Vult) of 107 mph (miles per hour) for Risk Category I buildings – these would be buildings unlikely to pose a risk to human life in event of a failure, or 114 mph for most other buildings (Risk Category II).

Given EF-1 tornado speed of 105 mph, there should have been minimal damage to any pole barn (post frame) buildings designed by a RDP (Registered Design Professional – architect or engineer) and built according to sealed plans.

In order for this to occur, all jurisdictions should be conforming – requiring Building Permits for structures, RDP sealed plans in order to obtain a structural permit to build, and jobsite inspections to insure conformity to building plans.

Not only do many jurisdictions allow construction without RDP designed plans, but some do not even require building permits!

In this or other areas where buildings may be subject to higher wind speed tornados, building owners can opt for greater wind speeds than Code minimum (keep in mind minimum is LEAST). In many cases designing to withstand higher winds is a nominal investment, so why not?

This entry was posted in Pole Barn Design, Building Department, Pole Barn Planning, Pole Barn Structure and tagged Building permit, wind speed, RDP sealed building plans, jobsite inspection on August 3, 2018 by admin.

Fire Resistance, Condensation, and Wind Speed

Fire Resistance, Condensation, and Wind Speed

DEAR POLE BARN GURU: Do you know if WMP-10 metal building insulation facing is ok to have exposed in a commercial building in regards to its fire resistance rating? JON

DEAR JON: WMP-10 facings are flame resistant, however you should consult with your local building code enforcing agency to determine if they will allow it to remain exposed given your use of the structure. An alternative might be Johns Manville FSK-25 faced batts which are laminated with an FSK (foil-scrim-kraft) facing, which enables the insulation to carry a fire hazard classification rating of 25/50 or less per ASTM E 84. The FSK-25 facing also serves as an excellent vapor retarder and may be left exposed where codes permit. The FSK-25 batts are a lightweight fire-resistant thermal and acoustical fiberglass insulation made of long, resilient glass fibers bonded with a bio-based binder.

Personally, I’d look at using unfaced fiberglass or rock wool batt insulation then covering the interior surface with 5/8″ Type X gypsum wallboard. Probably less expensive and would afford greater R-values with less of an investment.

DEAR POLE BARN GURU: I recently had a small pole barn constructed in Northern NJ which I’m about to insulate. Needless to say, the information regarding this is very confusing. The end goal here is to not have a condensation problem. With no insulation on the walls currently the metal walls sweat. The roof consists of metal roofing on top of “double bubble” on top of purlins with ridge vent and soffit vents. The walls will be filled with 6″ fiberglass and a poly vapor barrier applied. The ceiling will either be OSB or gypsum attached to the bottom of the trusses with blown insulation on top with no vapor barrier. With that said, my question is with this configuration, will the gable ends above ceiling height sweat or do they need to be insulated? If so what would be the recommended insulation?

Thanks, CONFUSED in NEW JERSEY

DEAR CONFUSED: With proper ventilation in your attic I won’t say it will be impossible to have condensation on the inside of the attic gable endwalls, however the probability should be small. If you want to make certain, an inch of closed cell foam can be sprayed on the inside of the endwall steel and it will eliminate any chance.

DEAR POLE BARN GURU: Are your plans for stick built frames or CBS frames or both? If only for frame built what is the wind ratio? SUNSHINE in JUPITER

DEAR SUNSHINE: Our buildings are neither stick built or concrete block – they are post frame buildings.

Since January 1973 anemograph stations within the United Kingdom have tabulated for each clock hour the mean hourly speed and the maximum gust (of approximately three second duration). The ratio of maximum gust speed to the mean speed for individual hours as an effective height of 10 meters is referred to as the gust ratio. The mean wind ration is the ratio of the extreme gust speed to the extreme hourly mean speed, both having a return period of 50 years. This ratio turns out to be 1.60.

Here in the colonies, we design using Vult (Ultimate Wind Speed). Until the 2012 IBC (International Building Code) we designed for Vasd (Allowable Stress Design) which is 60% of Vult.

One of the beauties of post frame construction is the buildings can be designed to support any wind load situation needed.

This entry was posted in Insulation, Pole Barn Design, Steel Roofing & Siding, Ventilation and tagged Vult, Vasd, insulation, condensation, wind speed, Insulation fire resistance on April 2, 2018 by admin.

PVC Pipe for Post Sleeves

Reader TOM in PURVIS shares a concept I had neither seen before nor had I even contemplated – using PVC pipe to protect post frame (pole building) columns from decay.

TOM writes: “ I know your posts are treated, but I live in the damp state of MS. In recent years 3 of my friends have pole barns, all of them very nice. But one in particular, the contractor added 8″ PCV pipe around the outside of the pole inserted into the ground – then concreted the pole. The claim is that this is an additional protection against termites and rot. It does appear to have given more protection from Mother Nature. Do you have an opinion about use of PVC when setting posts?”

Mike the Pole Barn Responds:
Virtually anything can be made out to be a benefit with a convincing argument. In my humble opinion, this builder is truly not adding any value to the buildings, and is potentially setting them up for failure from another act of Mother Nature – wind.
A properly pressure preservative treated column should out live not only us, but probably everyone else who is alive on the planet today (for more on the lifespan of pressure preservative treated wood please read: https://www.hansenpolebuildings.com/2017/12/will-poles-rot-off/).
The eight inch diameter PVC pipe probably just allows a 6×6 column to fit inside. Filling the balance of the pipe with concrete ads no real value as the concrete would never be over an inch and a quarter thick and work fracture under a load – either bending or withdrawl. This leaves whatever material is filled on the outside of the slick PVC surface to resist uplift forces. There is also an issue of connecting the PVC to the column, if unsealed holes are placed through the pipe by screws, bolts, nails, rebar, etc., water is going to get inside the pipe and the entire premise is defeated.
My opinion, if this was such a wonderful idea (and it actually added value) everyone would be doing it – just say no to the PVC pipe column sleeve.

This entry was posted in Lumber, Pole Barn Questions, Constructing a Pole Building, Pole Barn Structure, Columns, Pole Barn holes and tagged column lifespan, pole rot, post decay, wind speed, termites on January 31, 2018 by admin.

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