The Rot Doctor


Subject: descriptions of different kinds of rot
Date: Wed, 11 Nov 1998

Dear RotDoctor

I have heard that different forms of rot are more or less dangerous/serious in a boat - wet rot vs dry rot, etc. is this true? are there easy ways to tell the difference between these forms? what about the difference between these forms of rot and just water saturated wood that is soft and black (partially due to a tar floor coating). any photo websites or books i can look at for examples?

My boat is a 50 year old carvel hull not caulked bent frame dutch version of a 'folksboat' that has some (hope its not serious) rot.

thanks for any advice and direction

R. A.

All rot is serious in that it destroys or fatally weakens wood. No matter what kind of rot, "wet", "dry", the wood must be restored (via our CPES, which, because it is a hazardous material, we cannot easily get to Europe) or replaced. Rotted wood usually retains its structure, however weakened. The black mush you describe is a result of bacterial action, which usually takes place in situations where a lot of moisture is present over an extended period of time.

There are a variety of rot-producing fungi, but there is little practical advantage to knowing which is which. They all produce the same result: destroyed wood. Libraries will have books on rot, or sections on rot, especially in Europe, where the various maritime people have been fighting it for centuries. You can search the web, although there is less there than in the libraries.

From the point of view of your boat, if the wood is soft and easily punctured, it is rotten and will have to be replaced.

Good luck to you.