Last week we received a few calls from homeowners regarding mold growth on their bathroom walls. Therefore I think it is a good time to talk about moisture control in the home. Let’s start with the bathroom.
Mold in the bathroom is the result of not removing the moisture from the bathroom after taking a shower or bath. If you do not have a vent fan in your bathroom we recommend having one installed immediately. If you already have a vent installed, check to be sure it is free of dust and debris and then remember to clean it on a regular basis. We recommend cleaning the vent with a vacuum to remove the unwanted debris.
Installing a vent fan? How do you know the size of the fan you need?
- Measure the length and width of your bathroom. Multiply the two numbers together to determine the total square feet.
- If your bathroom is less than 100 square feet, use a fan that exhausts one cfm for every square foot of floor area. If your bathroom is sixty square feet, you need a ventilation fan that is rated for at least 60 cfm. To be on the safe side, the minimum size fan we use no matter what the size of the bathroom is 86 cfm.
- What does cfm stand for? It is short for cubic feet per minute, a measurement of the velocity at which air flows into or out of the space.
- If your bathroom is over 100 square feet, choose the size your fan according to the fixtures in the bathroom. Add 50 cfm for each toilet, shower or bathtub. If you have a jetted bathtub, add an additional 100 cfm. For example, if your bathroom has a toilet, shower and jetted tub, you need a ventilation fan rated for at least 200 cfm. (If in doubt give us a call and we can help you determine the right size for your needs.)
Now, if you have a clean and properly working vent fan and are still getting mold, it is time to dig a little deeper. Depending on the age and condition of the fan it simply may need to be replaced. Also, check the duct work for the fan.
A properly sized fan with improper duct work reduces the overall cfm of the fan. You’ll want to make sure the duct work is sized properly and doesn’t have any kinks in tight turns.
How to Check the Ductwork for Your Vent Fan
To check the ductwork for your fan, you will need to get into your attic and trace the ductwork from the fan to the outside of your home. If you are in doubt of how it should look and operate, check with your local contractor or home supply store for the proper ductwork recommendations.
We hope this information has given you some steps to take to fight off future mold from forming in your bathrooms. If you do have mold problems, please call a professional to assess the situation and determine what the best fix would be. Some mold problems are fairly easy to fix, while other require a lot more work and remediation.