Dry Rot vs. Wet Rot
Dry rot is another one of those old house problems that terrify the life out of people, and like woodworm is often misdiagnosed and treated incorrectly. The description “Dry rot” is incorrectly used by many, as an all encompassing description, of what are varies types of rotting timber. Dry rot is actually a very specific fungus “Serpula lacrymans” and is generically a “brown rot” type fungus.
There are however many other far more common types of timber decay/rot, which is generically be called wet rot. That may sound irrelivent to many people but it involves quite different levels of response.
Telling the Difference
Dry and wet rot are different in their causes and appearance. It is important to be able to identify just which type of rot you’re dealing with. This will ensure that the right treatment is applied.
Dry rot is one of the most serious forms of fungal decay you could encounter in a building. It exhibits the following signs:
- The fungi form a white growth that may have a lilac or yellow tint.
- Timber that is infected by the fungi forms deep cracks as moisture has been absorbed from it.
- The fungi infest both hardwood and softwood and causes extensive damage to both types of woods.
- An infestation is easily identified by the distinct smell of mushrooms.
Wet rot is common, but confined to timbers that have been exposed to high levels of moisture for an extended period. Some signs to look out for include:
- Discoloration, softness, distortion and cracking of timber
- Fungal fruiting bodies
- A damp musty smell
Treating Dry Rot
The major difference between the two types of rots is in the degree of the spread of the mycelium. The fungi that causes dry rot has the ability to spread into other timbers through masonry that is adjacent to the infected timbers. This ability makes it more dangerous than other types of rot. It can cause far much more damage. Treatment of this type of rot therefore, has to be more intensive.
The basic treatment plan for the two types of rots is similar. The source of moisture is identified and dealt with. The infected timber is then identified and replaced with preservative-treated timber. The area is treated with fungicide prior to the replacement of the timber.
When dealing with dry rot, the masonry in the space must also be treated with fungicide. This provides a protective chemical barrier that will prevent the spread of the fungi.
It is important to have the space inspected by a professional. This ensures that you accurately determine how widespread the infestation is and therefore treat all infected surfaces. This will provide long term results and prevent future infestation of the space.