So often in attic spaces especially in the Northeast region attics have large area spaces and most of the homes are very old. Many home inspectors keep pointing out that the ventilation or an improperly vented bath exhaust fan cause the mold growth. This can be true but in many instances of assessments but the real culprit for the mold contamination and growth is due to heat loss! Yes, heat loss due to lack of proper insulation R-value installed in the floor joist to keep the heat in its proper place – The Living Space. The purpose of insulation is to keep your home warm where you live and sleep not your attic. Attic space temperature is similar to outside space and should be within a five degree difference. During the cold or winter months films of frost eaves slightly buildup on the roof bays overnight. When the heat escapes into the attic area it melts the frost from the roof bays causing the plywood or pine boards to become moist and wet. The longer the moisture stays on the wood substance the greater potential for mold fungi is ripe to grow. Excess snow and ice dams standing on the roof can also be a causation for mold growth. Water seeps into the roof bays freeze and then melt due to heat loss or a rapid increase or spike in warmer temperatures i.e. 20 degrees Fahrenheit (F) to say 50 -60 degrees F in a day. In the northern climates attic experience this more verses warmer southern climates. Consider a mold assessment/inspection or an energy audit utilizing Thermal Infrared Camera optimization to determine if heat loss is occurring due to temperature differential Several energy audit companies observe this heat loos and moisture problem usually identifying some form of staining of the attic roof bays and recommended to conduct an assessment for mold before any insulation is added.
Andy Provitola CMC-Certified Microbial Consultant
Environmental Resources LLC
316 Washington Street
Norwell, MA 02061