The Rot Doctor


Subject: wood rot in dining room floor
Date: Sun, 08 Aug 1999

Home is 96 years old. Damage in dining room sub floor from radiator leak. Extensive wood root covering 4 square feet. What is the best way to check joists underneath if not visible? What would be the best method of treatment and application?


If you can't get under the joists to check them, then there is no way to look except by tearing up the floor. Not a happy prospect.

If it were me, and knowing what I do about the action of CPES (Clear Penetrating Epoxy Sealer), I would strip any finish left on the bad area, make sure the wood is reasonably dry (which it should be if you've stopped the leak and some time has passed), and then flood the area with the CPES. CPES is VERY thin, like diesel fuel, and will not only penetrate the deteriorated floor boards but will follow the same paths as the water did and get into the joists underneath. once there it will eliminate your problems with the rot fungi and reconstitute any soft wood in the joists.

This should take care of your problem. We have used this technique and it does work. The CPES will color the wood about the same as a coat of clear varnish, and can be sanded after curing (5-7 days) and covered with any finish you like.

If you were to undertake this, it should be done on a day when windows/doors can be open and you have good cross ventilation. CPES is a powerful mix and the fumes from the carrier solvents will pervade the room. You would want to consider wearing a mask capable of filtering organic fumes. The fumes do eventually disappear with no lingering odor, but you would be putting a lot on and it would be seeping down into joists. You should plan to stay out of the room for few days. And of course -- no open flames, smoking, etc.

My estimate would be you requiring at least a 2-quart unit, and maybe two of them to allow you the penetrating into the joists. You can order via on-line order form or by phone. We do ship the same day as ordered if the order is in before 2pm Pacific time. Come on back if you have additional questions.