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.


DEAR POLE BARN GURU: If I have a manufactured home that has been bricked in all around can I add a Pole Barn Home onto it? EDWARD in TENNILLE
DEAR POLE BARN GURU: How many bedrooms will fit in your largest residential barndominium. Thinking about using it as a dorm-type or assisted living. PHILLIP
DEAR POLE BARN GURU: I have an existing 40 x 60 pole building, built in the late 80’s. It has double trusses spaced 12 ft apart. I would like to extend it from 60 to 72 ft. We originally were thinking we would extend using stick frame construction but now I am wondering if this will affect the integrity of the existing building. I would like to leave the end of the pole building in place and add a door into the new space at each end. Your advice on the best way to go about this? The extension is planned for a bathroom and laundry space and would have a concrete floor. Thanks for your help. WENDY in VANCOUVER
Purlins are then in perfectly straight lines, allowing for pre-drilling of roof panels (this eliminates misses). Others may try to align purlins over top of trusses using butt end splices. This makes for a very poor connection attempting to get adequate fasteners into 3/4″ (1/2 width) of truss top chords. When purlin joints are lapped, it causes a stagger of the purlins, resulting in inability to pre-drill and a significant chances of screw misses.
DEAR GREG: Sounds like you are creating a dead attic space. You should order roof steel with a Integral Condensation Control (
DEAR JOHN: Your new Hansen post-frame building kit includes full multi-page 24” x 36” engineer sealed structural blueprints detailing location and attachment of every piece (as well as suitable for obtaining Building Permits), all lumber, trusses, roofing, siding, doors, windows, etc., to provide a complete ‘dried-in’ shell. Any raised wood floors (lofts, mezzanines, second or third floors) and applicable stairs. Our industry’s best, fully illustrated, step-by-step installation manual, and unlimited technical support from people who have actually built post frame buildings. Even better – it includes our industry leading Limited Lifetime Structural warranty!
DEAR POLE BARN GURU: Combination business and residential? Square footage of 7000. Can it be done? KEVIN in FLORISSANT
On the walls I plan to cut-to-fit the 1.5″ closed cell rigid foam board and install between the girts. After foam board is installed I intend to line all interior walls with painted OSB.
DEAR JERRY: In most instances floor joists will be supported by beams attached to wall columns. If you are looking at a design with zero barrier (think wheel chair accessibility) then you can excavate down and we can engineer a permanent wood foundation between columns. This allows for floor joists to be supported by short pressure preservative treated wood foundation walls and reduces your building’s profile.
In order to do this right you have only a couple of choices – you can spend a lot of money on an architect and/or engineer who physically comes to your site (could be as high as 20% of project’s finished costs). Or you can provide lots of information to us on what we are attaching to, as well as conveying your expectations. We will do anything reasonable to assist you in not making a mistake you will regret always. If I thought anyone else could not just actually do it but also do it better than us, with you being able to construct yourself, I would in all honesty let you know.
DEAR DAN:
If you spray foamed roof deck and have a dead attic space due to a flat level ceiling (we provided ceiling loaded trusses as well as ceiling joists) then you could experience condensation issues and potentially mold and/or mildew in attic, especially if attic is not made part of conditioned space (heated and/or cooled) with living area. If flat ceiling has also been insulated look out for trouble (keep a close eye on situation by doing visual attic inspections), as attic space could become quite a bit cooler than area below ceiling. Your spray foam contractor should have been talking with you about this prior to doing his or her application.
DEAR POLE BARN GURU: Should I put plastic down under the stone floor in a steel building? BOB in WYALUSING
LOAD (in psf – pounds per square foot) X (½ building width plus sidewall overhang in feet X 12”) X Distance spanned by beam squared (in feet)