The ongoing battle with mold in our homes
Prepared by Paul A. Polarek, licensed home inspector, Canal Port Home Inspections
With the onset of warm weather, the humidity goes up, and the result is the propagation of molds. Anywhere mold has grown in the previous season and gone dormant, it comes back with a vengeance. So, when you enter the house from the outside, mold spores stick to your hair, clothing and shoes. There is just no real effective way to avoid the transfer of mold into the house. I suppose that if we lived in a space age world, we might have that decompression chamber that might double as a mold cleaning station. This would allow us the opportunity to enter our houses without any mold interaction. Now if you have a penchant for leaving the windows open, yes, mold is small enough to get by the screens. And don’t forget about the attic vents where air (and mold spores) are fee to move in and out dependent on air currents. So now that your precious home is full of mold spores, what can one do?
There is little doubt that keeping your home prepared for the avoidance of mold propagation is important. The important goal here is to keep the amount of mold inside the home equal to or less than the amount of mold outside. Mold relies on water, condensation, moisture or high humidity and an organic food source to live. Surprisingly, most all of the methods for keeping the ability of mold from multiplying falls in line with the typical human comfort demands. For example, something as simple as placing a dehumidifier in the basement will take away molds ability to prosper simply because the RH factor (relative humidity…a measurement of water in the air) is lowered to an acceptable level. Likewise, the air conditioner which is a welcome relief in hot weather, also drops the humidity level in the living space that mold needs to survive.
The most neglected facet of the home seems to be the attic, and it’s there that mold has a field day! This is true for two main reasons: first, the amount of insulation in the attic is not taken very seriously, and second, the amount of venting or fresh air exchange in the attic most often times is also discarded. One must consider that especially in winter, hot air generated from the furnace rises to the ceiling and then by convection, moves through the ceiling surfaces and existing insulation into the attic air space. Two things can happen here: hot air meets cold surfaces and creates condensation as well as warms the roof sheeting and shingles thus melting any snow or ice…just a perfect situation for mold growth. Oh yes, under the right conditions mold can grow in winter as well. If enough insulation is installed in the attic, the transfer of heat to the attic open space is kept to a minimum (although not completely stopped.)
The amount of venting in the attic is crucial in both winter and summer. Proper venting in summer will help keep the house cooler, enhance the efficiency of the air conditioning, and prolong the life of the shingles. Such venting also will help to keep the humidity level in the attic lower in both winter and summer. In winter, when heat is moving upward by convection into the attic air space, proper venting allows cool air current to mix with the warmer air and dilute it. This prohibits the creation of condensation against the roof sheeting and ice dams.
Thus, whenever the possibility of condensation and/or moisture intrusion is eliminated, you have taken the biggest step toward eliminating the main ingredient to mold’s existence.