Weeping dry rot (Serpula lacrymans) is a formidable wood-eating fungus, often nicknamed the “cancer of the building.” Invisible at first, it can cause considerable damage to a home’s structure by attacking the wood. Its rapid and discreet progression makes it a real nightmare for homeowners. Early detection and professional intervention are essential to avoid serious damage.
What is weeping dry rot?
Weeping dry rot is a microscopic fungus that feeds on cellulose, particularly found in woodwork. It thrives in damp, dark, and poorly ventilated environments. Its name comes from the water droplets it can emit, which literally appear to “weep.” This fungus can remain dormant for several months, or even years, before becoming active as soon as the right conditions are met: high humidity (over 20%), low light, and moderate temperatures (between 18°C and 26°C).
How to recognize it?
Dry rot appears as a white, cottony felt, sometimes with orange or purplish highlights. It can also form filaments (called rhizomorphs) that allow it to spread rapidly through walls and floors. Wood attacked by dry rot becomes brownish, brittle, and cracks along the grain. A persistent fungal or moldy odor can also alert you to its presence.
One of the most worrying aspects of dry rot is its ability to penetrate non-organic materials, such as plaster or masonry, to reach other wood-rich areas. It can thus spread behind walls without being visible.
What are the risks for the home?
The damage caused by dry rot can be structural. By eating away at load-bearing elements such as joists, beams, or floors, it compromises the very solidity of the home. In the long term, floor or frame collapses can occur if the fungus is not eradicated in time.
Furthermore, dry rot is not only a pest of wood. Its growth also causes humidity and indoor air quality problems, which can impact the health of occupants, particularly by aggravating respiratory problems.
How can it be avoided and what to do if suspected?
Prevention relies on proper humidity management. It’s important to ensure that the house is well ventilated, that water infiltration is repaired quickly, and that the foundations are not retaining moisture. In the event of water damage, the materials must be dried out immediately.
If you suspect the presence of dry rot, do not attempt to treat it yourself. This fungus requires specialized intervention. An indoor environmental analysis by an expert like Benjel can confirm its presence and plan a safe and lasting intervention.
Conclusion
Weeping dry rot is a silent pest that can ruin a home if not detected early. Vigilance, humidity control, and professional expertise are the best ways to protect yourself against it. For a reliable assessment of your environment, call on Benjel, experts in air quality and contaminant detection.
