According to the Environmental Protection Agency (EPA), half of the structures in the United States contain mold. Mold often spreads in attics because this area often contains many of the key elements necessary for mold growth – water or moisture (especially with a roof leak), wood and other organic building materials on which to feed, and the right temperatures where mold will grow and thrive. Additionally, attics are often a non-living area of the home where people do not spend a great deal of time, so mold can spread over large areas before it is discovered. Often, one of the earliest signs of a mold problem in these cases, is an occupant who develops chronic, unexplained respiratory difficulties.
What is mold?
Mold is a fungus that reproduces via airborne spores and feeds on decaying organic matter. Outdoor mold is a valuable and necessary part of our ecosystem. Mold is often called nature’s decomposer. However, indoor mold is a serious health concern.
Indoor mold will grow once all of the elements necessary for mold growth are present in one location:
- Mold spores must be present. Mold spores are found everywhere. They are extremely common both inside and outside of homes. Mold spores are microscopic and cannot be seen by the human eye. There could easily be a large number of airborne mold spores in an attic without a homeowner ever even knowing they are there.
- Mold requires moisture or humidity. Because of condensation and roof leaks, attics contain more moisture and are more humid than other areas of the home. Once an attic’s indoor relative humidity exceeds 60%, the chance of mold growth increases significantly.
- Mold must have a food source. It can only grow in areas that have organic materials. Attics building material like wood, and because attics are often used for storage, they usually contain other organic materials like paper and cotton.
Why is mold often found in attics?
The most common causes of mold growth in attics are water or moisture problems resulting from:
- Condensation. Condensation is a common attic problem because this area of a home is the barrier between the outside elements and a home’s temperature controlled living area. When warm air from the living space of the home reaches the cold air on the attic walls and roof, condensation can form.
- Roof leaks. Unlike other areas of the home that are used on a regular basis, a leak that drips into an attic may go unnoticed for a long period of time. Roof leaks may not be noticed until the leak progresses enough to damage the top floor’s ceiling, and by that point, the attic’s mold growth could be extensive.
- Improper ventilation. Improper ventilation can create an environment that encourages mold growth. When moist air is allowed to stay in the attic, or when the attic is ventilated, mold has a much greater chance of spreading. When some homes were constructed, attics were used the attic as an area to vent air from other parts of the home, and moist air from bathrooms, kitchen ranges and dryers were all funneled into the attic. This is home building practices at their worse! In fact, this is so bad, that it’s against building codes in many municipalities. Sending moist air to the attic encourages mold growth.
Mold can begin to colonize in twenty-four hours after the spores find the right growing conditions. Mold will then likely continue to grow rapidly until something is done to change the environment in the area where it is growing by eliminating water or high moisture and humidity levels.
What are signs of attic mold?
There are three places to look for signs of attic mold growth:
- On your roof. When you are outside you should make a visual inspection of your roof and the area around it. Check for roofing shingles that may have been pulled off in heavy wind. Take special care to look for worn or warped shingles at the roof’s edge. Just below the roof line, look for warped or rotted eaves and fascia board. In the winter, look to see if there are ice dams in the gutters and in the warmer months check for leaves or other debris that can cause gutter issues. Any of these issues are signs of possible leaks.
- On the ceiling of your upper living space. When you are in your home, inspect the ceiling for signs of damage. These signs include ceiling paint that looks darker in some areas as well as ceiling plaster that is bubbling or expanding. Unfortunately, if the signs of the leak are noticeable within the living space, there is likely already a serious mold issue in the attic.
- In the attic itself. This is the most important place to inspect. Check the insulation in the attic for signs of moisture. Pay special attention to the insulation closest to the eaves. Look for warped or rotting wood anywhere in the attic. Check for possible leaks from the roof and make sure to inspect the area closest to the chimney (flashing is often installed improperly which leads to leaks). Of course, if you see actual mold, you know you have an issue with not just mold, but also moisture.
What is the best way to remedy attic mold?
Since there are a variety of ways moisture can get into an attic, this is not a homeowner DIY project. To protect your home investment, a reputable mold expert should inspect your attic to determine if there are any actual mold problems or if conditions exist for the potential for future mold growth.
A mold professional will be able to inspect the attic to find the source of the mold and remove the current mold growth. Work with a professional experienced with complete attic inspections. Mold is the symptom of some underlying water or moisture issue. Even if the mold is removed, if the source of the moisture is not addressed, the mold will likely return. It is just as important to prevent future mold growth as it is to remove the current mold.