Throughout the year, attic ventilation is critical element in maintaining attic temperatures. In the summertime, vents help remove excess heat. In the wintertime, air vents prevent the excess moisture from building up and water condensation from accumulating due to the temperature differences between the attic and the floor directly below.
Aside from an actual leak in your roof, the winter months are the time when moisture can lead to the growth of attic mold. During cold weather, warm air from the house can escape to the cold attic area. When warm air meets the cold surface of the roof boards of the floor below, ice crystals and water droplets can form. This moist environment, combined with a food source comprised of wood creates the perfect conditions for attic mold infestation and wood rot.
This problem can be compounded by bathroom exhaust fans that vent directly into the attic or into the soffit areas rather than outside the house. Moisture from bathroom fans is often the source of the attic mold contamination.
A balanced ventilation system is important. Incoming and outgoing air should be equal within the attic. It is important that bathroom fans are insulated around the exiting vent pipe. This helps to prevent moisture from condensing within the pipe – and creating another potential haven for mold to grow.
One of the most common ventilation mistakes is when homeowners combine different ventilation systems. This may occur when incoming air enters into the attic through soffits in the underside of the roof overhang. When these are combined with a different type of exhaust ventilation, problems can occur. For example, combining a ridge vent and a box vent can cause the ridge vent to draft moisture-laden air from the box vent. This can cause a cycle of attic moisture accumulation that can lead to significant damage. Mold releases enzymes that can rot and destroy wood. Exposure to mold can cause a wide range of potential health problems.
There is usually some level of saturated moisture in your attic. This is usually due to extreme temperature differences between the air temperature outside and the interior attic temperature. If large black or colored areas of mold appear in the attic, it should be inspected by a professional. If mold does exist, it can be treated and removed in a way that will prevent future growth.
Getting removing attic mold is important, preventing it in the first place is even more important. Your home's bathroom ventilation and air exhaust should be designed to put moisture as far out and away from your home as possible -no matter the time of year!