It happens to countless homeowners around Seattle,Wa area at the end of the year – you make the annual visit to your attic to collect the holiday decorations and what do you find?

Mold Spots and blotches covering the bottom of the roof sheathing

Worse yet – it turns out to be attic mold! What does energy conservation have to do with mold in the attic? Well, if you take a step back and consider how the house behaves as a system, they are often directly related. Building science experts have long been using the “house as a system” approach to diagnose the cause and origin of building defects. Bellevue residents rely on us for professional mold inspection services.

Understanding how the house behaves as a system and the various causes and effects is necessary to diagnose most building related problems. But how about that attic mold? How did it get there? Mold requires chronic moisture to form and to thrive, so source(s) of moisture must be present. Possibly the moisture came from outdoors. The roof is newer and a quick check of the roof shows no obvious damage or leaks. Possibly the moisture came from indoors. During the heating season, the interior of the house frequently has high moisture levels, especially bathrooms and kitchens. A quick check shows that all bathroom fans, kitchen vents, etc. are properly ducted completely outdoors and not into the attic. The amount of insulation looks good and the attic is well ventilated. Don’t give up – you are almost there! Remember the house as a system? You know that warm, moist air is in the house, but how is it getting into the attic? By air leaks! Air leaks are the leading source of energy loss in most houses, and a frequent source of chronic moisture that can cause attic mold.