You’ve seen it before. Black mold spots on the ceiling, mildew on shower tiles. Bathrooms are the most common place to find mold growth in a home. This isn’t surprising, as bathrooms contain all of the conditions conducive to mold growth: elevated moisture, food source and warm temperatures. If you are going to stop mold growth, you’ll have to reduce one of those variables. Getting rid of a food source for mold isn’t practical. Just about every surface except the tile and the mirror can foster mold growth. Eliminated the warm temperatures isn’t practical either. This leaves moisture.
Moisture occurs in bathrooms in three ways:
Airborne moisture (humidity), liquid moisture from plumbing leaks and liquid moisture from the shower and bath usage (splashing kids…). If you have a plumbing leak, there isn’t much you can do. Hire a plumber and address the source of the leak. However, if your leak is due to airborne moisture, there are many low cost techniques at your disposal.
First, check your ventilation. The primary cause of mold growth on the ceiling and upper walls is condensation. Warm, humid air from the shower or bath rises and hits the ceiling. The ceiling is much colder than the surrounding materials, causing the moisture to condense on the surface. Removing this moisture is best accomplished through a ceiling mounted exhaust fan. However, not all exhaust fans are created equal. If you have a bathroom fan and you’re still finding mold growth on the ceiling, you probably need a more powerful fan. Most builders install the cheapest fans possible, so even if it is making a lot of noise, it likely isn’t moving much air.
I prefer Panasonic WhisperGreen fans. They run continuously at a low speed and automatically ramp up to full power when the room is occupied. This works great when you have occupants (kids, renters, etc.) who may lack the inspiration to run the fan. With a properly working fan in place, the vast majority of ceiling mold problems will go away. If the problem persists, check the attic above for proper insulation. If necessary, add a few pieces of insulation directly above the bathroom. While you’re up there, check to ensure the exhaust fan properly ducts to the outside. If it terminates in the attic, you’ll soon have a mold problem there as well.
Upgrading your bathroom fan will reduce mold growth in other areas of the bathroom. Mildew on the tile will typically diminish as well. Additionally, by exhausting all of that warm, humid air from the bathroom, you’ll significantly reduce the RH (relative humidity) in the entire home. In many cases, you’ll see a dramatic reduction in window condensation throughout the house by running the bathroom fan more often.
Does bathroom mold cause health problems?
Typically, the quantity of mold growth in a bathroom is insufficient to cause health issues. The health effects of mold growth are dependent upon the quantity of exposure. For example, every time you walk outside, you are breathing black mold. In a clean, dry home, the level of mold spores you breath is less than typically found in the outside air. The small amount of mold growth present on the bathroom ceiling is likely causing no more additional exposure than a simple walk to the mailbox.
However, there is caveat. If bathroom mold growth is significant, it may indicate a home with systemic moisture problems. Condensation on the windows or a musty odor are good indications of this issue. If this is the case, the home very likely suffers from unhealthy levels of mold spores. Reducing the relative humidity throughout the home is the only solution. Thankfully, upgrading your bathroom fan may reduce the humidity sufficiently to stop the mold. When in doubt, hire an inspector to measure the moisture and humidity levels.
Author Bio: James Mallory is the owner of Environix, a provider of mold and Seattle lead inspection services.