Attaching Horse Stall Posts to Trusses – Just Say No!
Horse housing can be a significant piece of pie for post frame (pole barn) builders and building kit suppliers when economies are good. From 2007 to 2012, as U.S. economy tanked, horse populations decreased by 10%! Well, economies are cyclical and with a strong recovery a need for stall barns has increased.
What surprises me – only a very small number of what I would term “best designed” stall barns – designed with sufficient airflow for healthiest horses, are being built. These buildings do not have prefabricated roof trusses, instead they are built using poles (columns) and dimensional lumber rafters. For more reading about pole and raftered stall barns: https://www.hansenpolebuildings.com/2012/08/stall-barn/.
I scratch my head when I see clients investing in clearspan buildings to be used for equine housing. I am most familiar with pole and rafter buildings with poles every twelve feet, to accommodate building horse stalls. Reader SCOTT in DAYTON writes in as one of these who now facing some challenges of trying to correctly construct stalls in his clearspan building. He writes:
“I am installing dividers and horse stalls in a clear span structure. Interior posts need to be added two of which will attach to one of the rafters and serve as supports for the dividers and a stall front. Each post will consist of three 2×6 cribbed boards with treated lumber for the below grade pieces. The tops of the posts will be saddles so that I can through-bolt into the rafter. My question is: how do I set these so that they are neither supporting or hanging from the rafter? Do I dig the holes just shallow enough so that the top of the posts will be snug to the rafter or just hang them and fill the holes with concrete? Thanks!”
Mike the Pole Barn Guru responds:
Even after nearly 20 years as a Midwest import I am still not used to prefabricated wood roof trusses being referred to as “rafters”. Unless you have prior truss manufacturer engineer sealed approval you should not be connecting columns to truss bottom chords. While it may seem added support of a tightly fitting column might be an assist, under a snow load it may actually place loads upon truss in spots not designed for support and can lead to a catastrophic failure.
You may want to consider using either a solid sawn pressure preservative treated column, or a glu-laminated column with bottoms treated for structural in ground use, as opposed to nailing up a three ply 2×6 column where members can separate over time.
I’d be prone to place columns deep into the ground and completely backfill the holes with premix concrete, stopping columns well below trusses.