Subarctic Fairbanks. Winter lows can be from -15 to -50 degrees.
It’s no surprise that families living in Fairbanks seal their homes against the weather. However, when a dwelling is perfectly sealed to keep the weather out, it also keeps the humidity in. Which is why residences, especially rentals, in Fairbanks are having problems with mold and lack of ventilation, especially in older homes.
Humans exhale a lot of moisture—generated by cooking, showering and breathing—so that exacerbates the problem, as well as seasonal freezing, which deposits moisture in the spaces between the walls.
Walls need to breathe. Dwellings need to breathe, especially older buildings. There’s a balance in keeping enough insulation; and some builders are using a process of creating a double vapor barrier. The problem occurs in summer, when the moisture condenses from vapor to liquid.
Builders have worked out a thermal balance: 2/3 thermal insulation on the outside, 1/3 on the inside seems to be what works best to provide adequate insulation as well as vapor control. But all that goes out the window if the vapor barrier is pierced.
If you’re in California, you might want to give us a call and see about getting an assessment from Byebyemold.