What Is Trichoderma
Trichoderma is a genus of fungi commonly found in soil and decaying plant matter. In buildings, it colonizes wet cellulose materials like drywall, insulation, and wood framing. Unlike some molds that produce visible spore masses, Trichoderma often grows as white or greenish mycelium that can be harder to spot during initial inspections.
Why It Matters
Trichoderma matters because it actively degrades cellulose, which is the primary structural component of wood and paper-based building materials. This enzymatic breakdown weakens the physical integrity of your framing and sheathing over time. A 2016 study found that Trichoderma can reduce wood tensile strength by 15-30% within 6-12 months of colonization on untreated materials.
The mold thrives in humidity levels above 65% and requires consistent moisture to persist. It's frequently found in attic spaces with roof leaks, crawl spaces with poor drainage, and interior walls affected by water damage from plumbing failures. Unlike some molds, Trichoderma doesn't typically produce potent mycotoxins, but it can trigger respiratory irritation and allergic reactions in sensitive individuals, particularly in people with asthma or immunocompromised conditions.
Detection and Testing
Professional mold inspectors identify Trichoderma through tape lifts, swabs, and air quality testing. Lab analysis using microscopy or DNA sequencing confirms the genus. Air testing typically captures spore counts in the range of 100-5,000 CFU/m³ (colony forming units per cubic meter) in contaminated spaces, compared to baseline outdoor counts of 50-500 CFU/m³.
Remediation Standards
The EPA's Mold Remediation in Schools and Commercial Buildings guide (2008) classifies Trichoderma growth larger than 30 square feet as requiring professional remediation. For smaller areas, homeowners can follow containment protocols: isolate the space with plastic sheeting, use HEPA-filtered vacuums, and apply detergent or diluted bleach solutions (1 part bleach to 10 parts water). All wet materials must be removed and replaced since the enzymatic damage is permanent. After remediation, maintain indoor relative humidity below 60% using dehumidifiers and ensuring proper ventilation.
Prevention
Moisture control is the primary defense. Fix roof leaks within 48 hours, ensure gutters drain 4-6 feet away from foundations, and maintain bathroom and kitchen ventilation to exhaust moisture outdoors. Crawl space vapor barriers and sump pumps reduce ground moisture. In attics, proper insulation and ridge venting prevent condensation accumulation where Trichoderma thrives.
Common Questions
- Is Trichoderma dangerous to my family? Trichoderma is generally less toxic than black mold species, but it can cause allergic responses and respiratory issues in children, elderly residents, or people with asthma. If you suspect growth in occupied spaces, have it tested and addressed promptly.
- Can I clean Trichoderma myself if it's small? For areas under 30 square feet, you can apply detergent and bleach solutions after wearing an N95 mask and gloves. For larger contamination or structural materials like wood framing, hire a certified remediation contractor to ensure complete removal and prevent spore dispersal.
- How do I know if remediation worked? Post-remediation verification involves air and surface testing. Your inspector should document baseline moisture levels (below 20% wood moisture content) and confirm humidity stays below 60%. Some contractors offer 30-day follow-up testing to confirm no regrowth.