Prevent Mold in Your Home

Source : Dr. Virginia Salares, Senior Researcher, CMHC, September 2007

Mold of any kind growing inside your home can pose a serious health risk, especially if anyone in your family suffers from asthma or allergies. But as long as you know where to look, what to look for - and how to prevent or clean up mold in your home - you should be able to keep any potential mold problems under control, and keep your family happy and healthy.

What causes mold to grow?
Molds are microscopic fungi that are able to grow and reproduce rapidly. Molds are a necessary part of our environment - they break down waste and some even produce antibiotics.

A problem occurs when mold grows where we don’t want it to, such as inside your home. Once inside, mold can cause problems ranging from damage to materials, to allergic reactions and respiratory diseases. However, molds cannot be blamed for structural damage and wood rot, because technically, these are caused by other kinds of fungi.

So what can you do to keep mold out of your home?

Step One: Find out if you have a mold problem
Mold tends to grow almost anywhere there is excess moisture. This includes kitchens and bathrooms where there are plumbing leaks, wet or cold basements, wet windowsills or anywhere water is coming in through the floor, walls or roof. Kitchens and bathrooms will not have mold, unless there are unattended leaks or other moisture problems.

For mold to grow, you don’t need to see running water. Dampness can provide enough moisture for mold to grow. Daily activities like bathing, washing clothes, cooking, too many plants and pets, etc. are sources of moisture. Also, during colder weather, moisture can form on cold surfaces, such as window panes or walls that are lacking insulation.

Visible signs of mold are discoloration or spotting. If you suspect a stain to be mold, try dabbing it with a drop of household bleach. It may be mold if it loses its colour. Also, a lingering musty smell tells you there is mold.

Even if you don’t see mold or notice a smell, wet spots, dampness or evidence of a leak should tell you that mold either already exists or is on its way. Most people’s gut reaction when they suspect they may have a mold problem is that they want the house tested for mold. Test results will not help you so save your money, and use it to either clean up the problem or have a professional do it for you.

There are special challenges in northern or coastal areas. Dealing with mold requires a combination of strategies - ventilation, keeping surfaces warm and reducing moisture.

It’s also important to remember that mold is just one possible irritant that can lead to allergies or respiratory difficulties. Many other activities, such as smoking, storing toxic chemicals or harsh cleaners indoors, using an unvented heater or fireplace, burning candles/incense or using plug-in air fresheners can be an irritant for some people.

If someone in your family is having trouble breathing, make sure to look at other potential causes as well.

Step Two: Clean up the problem
If your house has a small patch of mold (no larger than about a square metre), you can clean it yourself using a simple solution of water and unscented detergent, household rubber gloves and a disposable respirator (mask) for protection.

If the mold patch covers an area between one and three square metres (say, about the size of a four-by-eight sheet of plywood), you may be able to clean it up yourself. But you need heavier duty respiratory protection and the work area may need special preparation. It is helpful to consult with a professional first to find out how the mold got there. Contact your local Canada Mortgage and Housing Corporation (CMHC) office for a list of qualified Residential Indoor Air Quality investigators in your area.

Being exposed to any amount of mold larger than three square metres for any amount of time is not a good idea. If your home has an extensive or recurring mold problem, seek professional help.

Remember, if you do clean up the mold yourself, using bleach is NOT recommended. Bleach will not cure the mold problem and can be harmful to those living in your home and to the environment.

Step Three: Prevent mold from forming
Of course, the best way to get rid of a mold problem is to prevent it from growing inside your home in the first place.

To start, find and fix any leaks that could be allowing water to seep into your home from the outside. Clean and replace your furnace filters regularly. Clean and vacuum your home on a regular basis, preferably with a central vacuum that vents outdoors or one that has a High Efficiency Particulate Air (HEPA) filter.

Get rid of excess clutter, because mold not only grows on stored materials that absorb and retain moisture, but clutter also reduces air circulation. Also, keep all areas of the house heated. Think of the ways you can keep your home dry. Hang wet laundry outside to dry when the weather permits, not inside. Use your bathroom and kitchen fans. From spring to fall, a dehumidifier in the basement is a must to control dampness in most regions of Canada. In the winter, when you see condensation on windows, this tells you that there may be too much moisture.

For apartments or rented houses

For people living in rented apartments or houses, the responsibility for cleaning up mold can fall with either the tenant, the landlord or both.

If you find mold, tell your landlord or superintendent about it, and get their permission before trying to clean even a small area. If the mold comes back after repeated cleaning, work with your landlord to identify and fix the
problem at the source.

Clear the air!
By following these simple steps, you should be able to keep your home mold-free - and your family safe and sound - all year-round.