Mold Related to No Attic Insulation – I received a call from a home owner who’s client was complaining about mold issues inside the home. Two mold tests were performed, but there was no information as to what was causing the mold growth. I was requested to do a site visit inspection to help in identifying the causes of mold growth.
WHAT WAS FOUND: In the photo below you can see this was an old Florida bungalow style home that has an un-insulated attic. In the 40’s when this home was built, New Yorkers and North-easterners would have these homes built for the winter months. They would reside in them when temperatures were lower and humidity was much more bearable. Modern living in this home means the use of window AC units at each room constantly cooling the interior. These units are not the best design for dehumidifying the home. Added to this there is an underfloor crawlspace, as was the construction method in the 1940’s in South Florida. In this case there was a broken sewer pipe discharging sewage and water under the home creating a very moist environment. Through what is known as the “stack effect”, air rises from the crawlspace, through the interior and finally out the attic and roof structure. This carries a significant amount of moisture through the home which is conducive to mold growth. Now, combine that with an un-insulated, brutally hot attic, open vents into the attic at the closets, and no air conditioning at the closets, these closets become virtual chimneys where warm moist air is rising through the closets and into the attic. The air carrying moisture at the interior of the home and in these closets meets the hot air in the attic, condenses on the cooler surfaces creating a perfect environment for mold growth.
THE SOLUTION: This attic should air sealed closing vents to the interior. Then the attic should be insulated with blown in cellulose insulation which works well in many cases to stop air movement. We did not recommend installing an encapsulated attic with closed cell spray foam insulation is this makes tenting for termites impossible in the future. Being that there has been a fair amount of termite activity at this home, this newer method of attic encapsulation is viewed as impractical. We also recommended installing a vapor barrier in the crawlspace to prevent the “stack effect”. Of course this should only be done after the damaged plumbing is repaired and the crawlspace sanitized and dried out.