A matter of dry rot

[Walter R.]

I have a concrete pad patio, 12x40 feet. It is covered by a heavy tile-roof overhang from the main house.

The roof overhang (12') is supported by three 8x8 wooden posts.

When they poured the slab, 25 years ago, they embedded the wooden posts about 4 inches deep into the concrete slab (I can tell from the screws). Therefore, the bottom of the posts are imbedded 4" into the slab and get wet whenever it rains: A perfect setup for dry rot in the posts.

Is there anything I can or should do about this in order to prevent dry rot? Anything to seal the joint between the slab and the wooden posts that are inserted 4" in the slab? Inject something into the posts?

[BobK207]

As you've already pointed out; direct wood/concrete contact is a no-no unless you've got treated wood. Embedding wood in concrete is also a problem.

Depending on the framing design, you might need the moment resistance that the embed gives you (at least until rot sets in)

Do you actually have rot or is this just a preventive measure?

I suggest something lke this:

they don't make an EPB for an 8x8

or

which they do make for an 8x8 but this product shows installl with the plate at the concrete surface.......better but not great. I like to have an inch or two standoff from the concrete to the post end. This way the post less likely to get wet or stay wet.

Another possiblity is that you could wait for the weather to get really hot & dry then drill some hole into the post 45deg down & inject some wood perservative into the post. But the only way to ensure good saturation is letting the end of the post soak in tray of the stuff.

Or maybe you could build a little dam around the post base & flood it with the wood perservative.

cheers Bob

cheers Bob

[Walter R.]

The outside of the posts is solid, but nobody knows what's going on inside or underneath. In that respect I am looking at it from a preventative perspective.

Maybe I should probe the inside/bottom of the posts with a long 1/4" drill. That would also enable me to infiltrate some fungicide.

[Goedjn]

It would also provide a convenient starting point for the kind of cracking and rotting you're trying to prevent. If the posts are far enough under cover so that they're not getting direct weather, and you don't get standing water on the patio, I'd say leave well enough alone.

With 8x8 posts, you might have to replace them once in your lifetime.

[Jack]

You could use the epoxy (the one as thin as water) for termite and dry rot repair.