Tag Archives: post sizes

Switching Post Sizes, Structure Length, and Fire Damage

This week’s ask the Pole Barn Guru answers reader questions about switching post sizes from a 6×6’s to 6×4’s, how long a structure can be built with 15 trusses with 2×4 chords, and if it is possible to rebuild on a slab that was part of a fire loss.

DEAR POLE BARN GURU: I am about to buy my post for a residential post barn using 6 x 6 x 12 post in Sottsburg, Indiana. A neighbor suggested instead of using 6 x 6 x 12, to use 4 x 6 x 12 in substitution for some of the post that would be none corner or door support post. My question would be can it be done and meet building code being it will not have an attack or vaulted ceilings? LEVIA in SCOTTSBURG

DEAR LEVIA: In most instances a 4×6 #2 will be stronger than a 6×6, however switching out columns should only be done with approval from your engineer who sealed your building plans.

For extended reading on this subject: https://www.hansenpolebuildings.com/2019/04/when-size-or-lack-thereof-matters/


DEAR POLE BARN GURU: 2 x 4 Truss spacing question, how long do you advise to build a Pole barn with 15pcs of 2 x 4 x 24′ engineered trusses? 🙂 The fires got 8 of them so I’m refiguring my length, but wanted some help on the truss spacing? Thanks, MARSHALL in PORTLAND

DEAR MARSHALL: The engineered truss drawings will provide maximum on center spacing of trusses. With 2×4 chords, I would suspect this to be 24 inches. With 15 pieces, you could build a 28 foot length building.


DEAR POLE BARN GURU: I’m working on a fire loss to a post frame building that was converted to multi-unit apartments. The building shell is post frame on slab with interior walls framed. My question is could we demo the building saving the slab rebuild utilizing standard residential stud wall and truss framing. Thanks CHRIS in FLOYDS KNOBS

DEAR CHRIS: Heat from a fire can result in concrete chemical composition breakdown. Other effects include concrete spalling, seen as large pits. Concrete may have protected substrates below, but further investigation is probably required. Water used on fire can also adversely affect soils below. Have an engineer familiar with concrete test for strength. Sometimes it may look like concrete is okay, but then later it begins to crumble.

Outside of this, slabs for post frame buildings do not have continuous footings and stem walls, or edges thick enough to provide protection from frost heave and to support imposed loads from building dead weight and imposed loads.


Posts and Collars, Girts, and Non-Vented Soffits

This week’s edition of Pole Barn Guru visits the topics of post and footing sizes, bookshelf girts for drywall, and non-vented soffits for building with spray foam insulation.

treated postDEAR POLE BARN GURU: I am currently 68 but I built pole barns as a younger man the biggest being a hay barn 24′ eaves X 80 clearspan trusses that we built X 160′ long. I am going to build a 30×60 and will use 6X6 posts 12′ to eaves, engineered trusses with 2X6 purlins 12′ span.

What diameter hole do I need?

I was thinking of using a 16 or 18 sonotube top of an 8″ footing below pour.

Does that sound reasonable?

I am in Grant county Wa.

Thanks for your time 🙂 JOSEPH in SOAP LAKE

DEAR JOSEPH: We have had clients much older than you, with no prior experience, successfully erect their own beautiful post frame buildings. Your 80 foot clearspan x 160 foot long and 24 foot eave must have been quite impressive structure!

Most of your area’s building sites are Exposure C for wind (open to the wind in one or more directions – https://www.hansenpolebuildings.com/2012/03/wind-exposure-confusion/), which is default value for Grant County. If this is indeed your case, neither 6×6 posts or 18 inch diameter holes would be adequate. One of our Building Designers will reach out to you to further discuss your building needs.


DEAR POLE BARN GURU: After reading all of the advantages of bookshelf girts I still find the idea of installing drywall sheets vertically over them a bit perplexing. Is vertical “strapping” of some sort required in addition to the girts or is there enough rigidity between the girts to keep the seam together? I’m assuming this would require the use of 5/8 thick sheets. We are planning on doing as much of the work as possible so our plan would be to have all of the ceilings hung by a pro and do the vertical wall hanging ourselves. All of the details for top of wall to truss connections and the prep make perfect sense to me, why does this detail escape me.
Always thankful for all of the useful info we have learned from your site. We are getting closer by the day to being ready to have our plans prepared for building. RUSS in PIPERSVILLE

DEAR RUSS: Thank you for all of your kind words, they are appreciated. The horizontal bookshelf girts will be stiff enough being attached to both the exterior siding (whether wood or steel) as well as the interior drywall to keep your seams together, without need for blocking at seam edges. You will find your sheetrock joints will be much smoother with vertical installation across these girts (https://www.hansenpolebuildings.com/2019/09/11-reasons-post-frame-commercial-girted-walls-are-best-for-drywall/). I used 5/8″ Type X drywall in my own shouse (shop/house) – because it is much more durable, absorbs sound better and provides fire resistance, however 1/2″ would have worked equally as well for standard performance.


DEAR POLE BARN GURU: I am looking at purchasing / installing a 30’X50′ pole barn style building with 16′ ceilings, including two 12’X50′ lean-to on each side and 12′ ceilings
I want to enclose about 12’X25′ of the left side lean-to for a canning kitchen area.

I am going to have a non-vented insulated roof assembly since we are using a closed cell foam spray, My question is would using 12″ closed soffit overhang be acceptable for the entire building.

Thank You in advance for the support, SAMUEL in CORINTH

DEAR SAMUEL: In my humble opinion most buildings without overhangs look overly industrial. Overhangs help to keep your building sidewalls cleaner and push rain runoff away from your structure. We can provide non-vented soffit panels and they would work perfectly for your application.