My home in CA is over 35 years old and was originally sided with T-111 5/8x 8″ grooves. The stuff has been nasty and has required constant maintenance, patching, replacement panels and painting. dry rot, woodpecker damage, blistering, etc.
It’s still structurally sound and I have finally decided to wrap it in Tyvek and side over with Hardie Cedarmill nailed at every stud.
My question relates to the front entryway of my home. In this area (which has about a 4′ overhang) the builder put the T-111 right down to the concrete. It doesn’t get constantly wet there, but I do occasionally pressure wash, etc.and always worry about the t-111 wicking moisture.
My concern is if I should do anything to the bottom of the T-111 before I sandwich it in with Hardie. I considered caulking the bottom few inches with some type of Butyl caulk, so that anything dripping down the siding or Tyvek would not get to the t-111. But then again, that would make it harder for the plywood to dry out if it did wick water from the concrete. Or, I guess I could saw it up about a 1/4 inch and put some type barrier under it.
Any ideas on this?
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What's behind the T-111 down there? Treated wood plate? Untreated wood? Something else?
(What I did in a slightly different scenario is cut away some "beaver board" sheathing and replace it with a piece of "cement board" tile backer, after doing the best I could to waterproof the area behind.)
cut is off the concrete but cut more than just a 1/4" specially if your going to cover it up, i would cut as far up as you need to be able to paint the newly exposed edge.
Check the specs for Hardie clearance and cut back and seal/flash the T-111 just above at a minimum.
There's A Lot To Do
Concrete, even in the middle of Death Valley, is "wet." For both moisture damage and insect concerns, that T-111 needs to be cut until it is several inches - I think they want 6" in termite areas - above any concrete on grade. Any wood product in direct contact with concrete, like your mudsill, needs to be made of treated lumber.
I'd remove the lower foot and fill it with single course of cement-board siding, like Hardieplank. Then proceed with your re-siding.
I advise against caulk- at best you'll only create a 'bucket' that traps moisture in the wood.
Treated mud sill, with untreated framing above, behind the T-111.
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cemiii wrote:
Treated mud sill, with untreated framing above, behind the T-111. Looks like 15# felt between siding and framing, no seperate sheathing.
Thank you for all the helpful comments. Since it's EQ territory (Bay area), I'm a bit concerned about cutting the T-111 way above the mud sill as it is the only sheathing for that wall. Based on the comments, I am now considering a compromise of cutting off 1-1/2" of T-111 (which coincidentally is blade height of the circular saw laying on the concrete), shooting some more nails in the bottom of the T-111, painting the new cut, and butyl caulking in 1-1/2" of 3/4" Solid PVC board (Vendura, I have on hand) as a non-wicking filler and surface water dam for the sill. Leaving the top of the PVC uncaulked should leave some air gap for the outer edge of the mudsill. I don't think I'll nail the PVC board as it might crack it, and it has no structural function. I'll make sure the house wrap comes down over the PVC.
Fortunately, over the years, I have not found evidence yet of sub terrainian termites, though I have had a couple small instances of dry wood T's above the first story roof line,that were treated effectively with Premise Foam and T-111 panel replacement. Those suckers must love T-111 glue in their diet.
It is my own home and so I am more interested in best overall function for the specific situation, than specific code.
I'm also pleasantly surprised to find that this is an active forum with lots of pros offering great advice. Thank you.