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.