Wet Rot vs. Dry Rot: Differences and How to Treat Both

Wet rot is a fungal decay that needs high moisture content in wood, usually above 50 percent. It often appears near leaking pipes, poorly sealed windows, or areas with poor ventilation. The wood darkens, softens, and may crack into cubical patterns, but the fungus does not spread far beyond the wet zone.

Because wet rot stays localized, you can often stop it by fixing the leak and drying the wood thoroughly. Remove any decayed timber and replace it with treated lumber. If you live in Kirkland, keep an eye on areas where water might linger, like crawlspaces and window sills.

To tell them apart, probe the wood with a screwdriver. Wet rot makes the surface soft and spongy, and the wood may feel damp. Dry rot, on the other hand, often appears as deep cracks across the grain, with a musty smell and sometimes red-brown spore dust.

Check the surrounding area. If you see fungal strands or greyish sheets on brickwork or plaster, that is more likely dry rot. Wet rot typically stays confined to the wood itself. When in doubt, a local water damage inspection can help identify the type and extent.

Dry rot treatment is more involved. You need to locate the original moisture source, which might be a hidden pipe leak or poor subfloor ventilation. Remove all infected wood, plus a margin of healthy-looking wood around it, because the fungus can spread invisibly.

Treat the surrounding masonry and soil with a suitable fungicide. Improve airflow to keep the area dry. In severe cases, you may need to replace structural timbers, so have a professional assess the damage first. Prompt action can save you from costly repairs.

• Fix the moisture source before any repairs
• Remove all visibly infected wood and a safe margin
• Treat surrounding surfaces with fungicide
• Improve ventilation in crawlspaces and basements
• Replace with pressure-treated or naturally resistant wood
• Monitor the area for new signs of rot