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We had a water leak in a house and then mold problems. Now I see signs of dry rot. Can you help?


We had a water leak in a house and then mold problems. It was cleaned out, but now I see signs of what I think are dry rot, which I’ve learned doesn’t need a lot of humidity to grow. Can you offer some guidance on this issue?


Dry rot is caused by a fungus. Unless the source of moisture (leaks, sprinklers, rain, condensation) is corrected, wood decay could continue to re-infest seasoned wood. It can cause severe structural damage to any wood member, even wood species such as redwood and cedar. All that is needed is a source of water in contact with the wood. Decay will usually occur in untreated wood in direct contact with ground, cement or concrete, or exposed to a source of moisture such as rain seepage, plumbing leaks or condensation.

Brown Rot is a fungus that feeds on the wood's cellulose, a component of the wood's cell wall, leaving a brown residue of lignin, the substance which holds the cells together. Infested wood may be greatly weakened, even before decay can be seen. Advanced infestations of brown rot are evidenced in the wood to be more brown in color than normal, tending to crack across the grain. When dried, wood previously infested will turn to powder when crushed. Often, old infestations of brown rot, which have dried out, are labeled as "dry rot." This is really a deceiving term since wood will not decay when dry.

When white rot attacks wood, it breaks down both the lignin and cellulose causing the wood to lose its color and appear whiter than normal. Wood affected by white rot normally does not crack across the grain and will only shrink and collapse when severely degraded. Infested wood will gradually lose its strength and become spongy to the touch.

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