Strange Claims of Entry Doors Moving
When it comes to post frame (pole) buildings and barndominiums, stories being shared often sound like they originated in Twilight Zone episodes.
Reader STEVE in MERCER writes:
“Everyone I talk to recommends one side of the man door be a structural post but there is a 50/50 disagreement on the other side. Some say you need another full length post from the trusses down while others say it’s best to use 4×6’s only up to the top of the door. Some of them state they have seen doors shift and no longer open or close correctly on buildings with the 2 full length posts and haven’t had this happen with the shorter 4×6’s. It sounds like a strange claim so I am wondering if there is any truth to it and is one way better than the other or are they both equally acceptable? Any help you can provide will be greatly appreciated.”
Mike the Pole Barn Guru responds:
In an ideal world, I suppose one side of an entry door should be secured to a roof supporting column. Until just a few years ago, we did not give clients a choice but to do so.
In reality, entry door locations seem to have a mind of their own(ers), as far as where they get placed. There is actually no structural reason to run columns on each side of entry doors up to your building’s roof line provided:
Columns are adequately embedded or wet set bracket mounted to avoid ground line movement;
Column tops are effectively secured to a header able to transfer loads from door posts to roof supporting columns. In most cases, this header will need to be a bookshelf style girt, rather than externally mounted.
Doors should only shift if the site has not been properly prepared to avoid heaving due to frost or expansive soils. Any clays should be excavated from site and replaced with properly well compacted materials. Finish grade should slope away from building for eight to 10 feet at a 5% or greater slope. Downspouts from gutters should discharge 10 feet from the building perimeter or into appropriate drain lines diverting runoff well past the low side of the building. Any underground water flow should be channeled into French drains.
Basically keep the fill underneath the building area dry (or in expansive soils – at a constant moisture level).
With new 2021 Building Codes being adopted, egress doorways will be required to be frost protected – this being best done with use of rigid polyiso board below grade.