What is Dry Rot & Brown Rot?
“Dry Rot” is a term most often used to describe a particular kind of dry, cracking, rotting wood. However, dry rot occurs because of a variety of brown rot species, most notably the “true” dry rot fungus known as Serpula lacrymans. Dry Rot originally got its name from the thought that it didn’t need water to live, but instead used a fermentation process to survive. Research long ago proved that theory untrue, and dry rot is now more appropriately called “brown rot.”
Dry rot needs much less moisture than other types of wood-rotting fungi — a wood moisture content of just 28-30% — to survive. While there is no official proof on the subject, many contractors have observed that dry rot also will not grow on wood with too much moisture.
Protect Your Home From Dry Rot!
The Bad News
The Good News
- While dry rot is not the most common type of rot, it can deal serious damage to your home and endure conditions that are too dry for other types of rot to thrive. In fact, up to a 75% loss in the toughness of the wood [PDF] is possible with just a 1% decrease in the wood’s weight of the wood.
- Dry rot fungus spores are present in most homes and can survive for several years, waiting for the right conditions to grow.
- Dry rot can pull moisture from moist areas to dry areas. It grows through mortar, concrete, masonry, and behind plaster.
- Despite its name, dry rot needs moisture to produce spores– at least 28-30% moisture content within the wood with a relative humidity of 95% or higher. Most softwood timbers in dry homes, especially in the upper levels, have a moisture content of 12-15%.
- Dry rot problems in basements and crawl spaces can easily be solved by controlling moisture by sealing and dehumidifying the space.
- Treatment of the wood products such as boric acid is known to eliminate and prevent dry root fungi.
Identifying & Treating Dry Rot or Brown Rot Problems in Pennsylvania and New York
Damage from dry rot creates small, rectangular pieces of crumbling wood on the surface. Dry rot damage is often mistaken as a termite infestation.
A common first indication of dry rot in a home is the appearance of a “red brick dust”. This is actually an accumulation of fungal spores that are covering the surface, waiting for the proper conditions to start to grow.
An outbreak of dry rot commonly occurs several months after a household water event, such as flooding, bursting washing machine hoses, a failed water heater, or leaking pipes.
Dry rot is also common in vented crawl spaces and basements with groundwater flooding.
Dry rot is often not detected until the damage is already very significant. At this point, the following steps are recommended:
Steps to Dry Rot Cleaning & Repair
- Remove Damaged Wood: All wood that shows decay or visible fungus should be removed, as well as all wood within one meter of the visible decayed material.
- Remove Materials Near Damage: Plaster, paneling, linings, and ceilings around the dry rot areas can also contribute to the damage and should also be removed.
- Wire brush Affected Area: Using a wire brush, loose material is removed from all surfaces within 1.5 meters of the furthest edge of the infestation, including metal, masonry, and pipes. Resulting dust and debris is removed as well.
- Disinfect area: A disinfectant is applied to all wood, masonry, and exposed soil in within 1.5 meters from the damage.
- Rebuild: Substantially rot-damaged beams, joists, and posts are replaced with pressure-treated wood.
Preventing Dry Rot in a Basement: Remove all standing water sources, then install a plastic vapor barrier on the walls and floors. Install a self-draining dehumidifier powerful enough to dry the area. (At least a 100-liter model)
Preventing Dry Rot in a Crawl Space: Seal off all crawl space vents and door covers. Encapsulate the crawl space with a crawl space liner, then install a self-draining crawl space dehumidifier.
Dry Rot Alert!
Architect’s Journal reports that dry rot can grow through damp mortar, concrete, masonry and behind plaster.
This makes remediation of dry rot complicated and expensive, and it can lead to future problems with dry rot if it is not treated properly.
Preventing Dry Rot Problems in Your Basement or Crawl Space
Klein Home Solutions can help you eliminate dry rot problems at their source. We can dry your basement or crawl space, eliminate flooding problems, and seal out humidity.
This not only eliminates dry rot problems, but also creates an environment that is inhospitable to mold, wet rot, and mildew, while helping to keep out termites, carpenter ants, cockroaches, crickets, and other household pests.
We offer FREE, no-obligation dry basement and crawl space quotes in our service area. We can answer all your questions and point out the sources of humidity and moisture in your home.
We service Pennsylvania and New York, including Erie, Warren, Chautauqua, Crawford, Ashtabula and nearby areas such as Ashtabula, Fredonia, North East, Edinboro, Titusville, Harborcreek, Waterford .