Healthy Indoors Magazine
Issue link: https://hi.healthyindoors.com/i/1196895
Healthy Indoors | 17 Mold growth can also be found above-grade in prop- erties located near water, properties with intermittent occupancy, and properties that have gone through fore- closure and have been empty for a while. It's common to find mold growth on the bottom of piano benches. May Indoor Air Investigations LLC Members of my own family own a vacation home in northern New England. They used to go to the house during winter vacations, when they operated the wood stove and cooked lots of food for their children and their friends, filling the house with warmth and moisture. They put a pot of wa- ter on the wood stove to moisten the indoor air. When they left the house, they turned the heat down below 50 o F. Conditions of elevated RH developed. I found mold growth on the bottoms, sides and backs of many pieces of furniture, as well as on the bottom foot or so of exterior walls and curtains covering sliding glass doors. Some Tips: Here are some tips to help you with your inspections as well as to pass along to your clients: • A raised floor in a finished basement can hide all sorts of ills, including moisture intrusion, mold growth and wood rot. • Window-cap and door-cap flashing should be sloped away from rather than toward the cladding. People can add a bead of caulk at the inner edge of such a flash- ing to redirect the slope. They can also create "caulk dams" at the ends of the flashing to prevent water from entering the trim/siding interface. • An alternative to a drywell would be installation of solid, 4" PVC piping a few inches below the soil. The piping can extend to daylight downhill from a building or at the edge of a deep landscape furrow, and a downspout can be inserted into such piping. The wrong way to vent a dryer May Indoor Air Investigations LLC Some older houses in New England have hot-water or steam heat with a separate, ducted air-conditioning sys- tem. Returns (especially those located in hallway ceilings near bathrooms) as well as ceiling supplies in such hous- es should be closed during the winter to prevent the flow of moisture into the ducts, where mold could then flourish. Relative humidity (RH) below-grade: As air cools, its RH rises, so below-grade spaces are prone to developing high RH conditions. It's not therefore surprising that some molds commonly grow below-grade when the RH is not or has not been adequately controlled. Unfortunately, mold spores remain potentially allergenic even when dead. The RH in unfinished basements should be at or below 50% and in finished basement spaces, 60%. During the humid season (in New England, generally between mid- April and mid-October), unfinished basements must be dehumidified. Finished basement must either be air con- ditioned or dehumidified (or both, if necessary). During the heating season, unfinished basements do not need to be dehumidified, but finished basements must be consistently heated, whether in use or not, with the thermostat set at a minimum of 60 o F.