The Rot Doctor


Subject: attached greenhouse
Date: Tue, 01 Jun 1999

hello--glad to find you on the web! recently cloroxed the moldy wood under the window-wall of my sunroom--the wall was ill-designed and had leaked at the corner of each of seven large windows until i found a product and a person to help correct it. the wall is about six years old, but apparently the heat and humidity in the room have accelerated the process of rot to the extent that four of the seven structural rafters are rotten up to window height--i am resolved to pull the siding off the outside to get a good look at the extent of the damage. i dug out a lot of punk wood from these beams on the inside, not realizing there was a product that could immobilize the rot. i am planning to replace the wall under the windows because i think the damage is throughout, and the wall needs to be redesigned so it doesn't happen again. can you tell me something about the spores in these walls--are they airborne, how can i protect the rest of the room during reconstruction? i recently found a mushroom similar to one that had sprouted out of the bottom of the greenrock on the wall before i removed it last fall. does this mean that the spores have permeated all the soil in my houseplants! am i being invaded by microbacilli?!


Yup, you DO have a problem! And you are right -- it's the combination of heat and moisture which are encouraging the rot fungi to propagate.

You do need to tear off the siding and have a good look at what's going on and on how far the damage has gone. You can be sure that the entire area is infested with rot-producing fungi and their reproductive spores. They will be harmless to your plants, but they will continue to attack unprotected wood.

What you do now depends on how far the damage has gone. In posts and beams where the damage is not throughout you can coat the wood with the CPES (Clear Penetrating Epoxy Sealer) and preserve it. You should, in fact, coat every piece of wood, damaged or undamaged, with CPES, paying particular attention to joints, end-grain and the like. Beams/posts that are replaced should be replaced with treated lumber which is then ALSO CPES-treated, again especially on end-grain and joints. An alternative would of course be to use aluminum or steel posts and beams, but this would basically mean re-building the entire structure.

Wood that has been thoroughly CPES-treated is very rot resistant.

The fungi you found is not necessarily rot related, as fungi exist independently of rot-producing fungi. Still, as I noted above, you can be sure that rot fungi and their spores are throughout. There's no way to get rid of them. You can only protect the wood.

Come back if you have additional questions or comments.