The Rot Doctor


Subject: Siding Rot
Date: Tue, 25 Apr 2000

Dear Dr. Rot,

I really need your help. I don't even know if what we have is dry rot, I suspect that even though it's all wet now ('cuz it's raining) we're really talking about dry rot. The satellite dish guy came today to replace our Primestar with Direct TV (Direct TV bought Primestar). He went outside to run the new cable in and discovered that our siding is rotted all around where the Primestar guy drilled a hole for the old cable. He couldn't even get it to hold a nail. I haven't been home yet to see it, but apparently the wood is all spongy in that area.

After initial outrage that our not quite 5-year-old house is rotting around us and fruitless efforts to track down the builder of our spongy house, I decided to go the Web for a solution. Voila! I found you. So I hope you don't mind answering some really stupid questions.

Is what I described above dry rot?

It's rot. There are a variety of rot fungi, depending on location and a few other things, but they all produce the same results: Spongy wood. There are bacteria as well that can deteriorate wood. Doesn't really matter what it is.

Can CPES fix it? There is no exterior sign of rot (like in the pictures on your Web site), but maybe it's just being held together by the paint.

CPES can most likely fix the wood. It IS wood isn't it, and not some sort of particle siding?

Do we have to remove the boards that have rot in them? Your answers seem to indicate not, but then a lot of your answers talk about "after you remove the rotten wood".

Generally in your situation the boards can be left in place. "After you remove the rotten wood..." generally refers to situations in beams and frames that are structural and where the rot is very deep.

How do we tell how extensive the rot is? The siding is all painted and I can't tell by looking since I never suspected.

By poking at the exterior with something sharp, such as a knife or ice pick. Where it punches easily into (and maybe through) the wood, it needs treatment. Where it's solid, it doesn't. You use this technique to actually "map" the area to be treated.

Do we need the Layup and Laminating Resin also?

Probably not, since siding boards are not structural. You just want to solidify the bad wood and stop the fungi/bacteria from further activity. CPES will do that.

One series of sort of unrelated questions, you had mentioned something about a damp crawl space being bad. We have a crawl space that sometimes has standing water in it. I take it that this is really bad.


Our crawl space is about 3 1/2 feet high and runs under the entire house. It has vents all around it which is how I suspect the water gets in.

No, water should not be getting in via the vents. They should have downward vents that prevent this from happening. Possibly a tiny bit could be squeezing through, but not enough to cause standing water.

Could this have something to do with our rot problem?

If the exterior rot is down low near the crawl space it's possible that it is contributing to the problem.

Does it mean that we should check the entire house? Should we invest in a pump to keep our crawl space dry?

You should get into the crawl space and check all the wood up under the flooring and the perimeter structures of the house. Use the knife or ice pick. You should also find out how the water is getting under the house...perhaps by exterior drainage. If it stays that moist down there you'll eventually have deteriorated wood.

I don't know if this makes any difference, but we live in central Virginia. We're in a rainy spell right now, but it should dry out soon. It's a lot easier to get three or four days of dry weather in a row here than in Seattle. I was born and grew up in Seattle. Yeah, I miss it, but I've gotten used to less rain.