Mold Creation Prevention

Source: Society of Canadian Mortgage and Housing

Prevent the formation of mold

  • Keep your home dry;
  • Make sure all traces of leaks and close them;
  • Get rid of unnecessary items;
  • Clean and maintain your home periodically;
  • Adopt lifestyles promoting the reduction of moisture inside.

Basic steps to prevent and reduce the formation of mold

  • Mold needs a moist environment to grow. It can help prevent its formation by controlling the humidity and keeping the home dry;
  • Look for any indication of moisture and mold;
  • Find out if water seeps from the outside or if there is a lot of moisture inside the housing; 
  • Report immediately any water leakage, evidence of mold or moisture in the condominium board;
  • Pay attention to the different ways to produce moisture inside the housing (for example, cooking and bathroom, plenty of plants). Eliminate moisture as soon as it is produced by use of exhaust fans. If there is not, open the windows for a short time, but remember that air currents can push the moisture to other parts;
  • Measure the moisture content of the air. To determine the relative humidity in your home, you need a hygrometer, you can buy one for a price ranging between $ 5 and $ 20, a hardware or electronics store. Keep the relative humidity in your home below 50%. Make use of a dehumidifier to lower the relative humidity;
  • Reduce the amount of stored items, especially the ones you do not use anymore. Mold grows on fabrics, paper, wood and practically any item that collects dust and holds moisture.

Mold prevention

Protect your home against mold, piece by piece

Basement or crawlspace

(Note: This section was written for homeowners. Some principles apply to basements condominium. Contact your Council owners...)

  • Reduce the amount of clothes, paper and stored in the basement furniture. Have items in poor condition. Keep the basement tidy so that air can circulate freely. Keep only the items you can wash;
  • Do not cover the floor carpet in the basement;
  • Periodically clean the drain sub-sol. Put a half cup of bleach solution, let sit for a few minutes, then rinse with large water. Check that the siphon is filled with water;
  • Avoid standing water. Keep closed sump. (You can wrap a plastic piece of plywood and use it as cover.)


  • Frequently clean and replace furnace air filters. Make use of pleated filters, an inch thick, not prefilters;
  • If you have a heat recovery ventilator (HRV), often clean the filter inside the unit;
  • If you see signs of mold or moisture (condensation on windows or wet surfaces) Avoid wet. Unplug the humidifier furnace if it is more;
  • If you have electric baseboards, vacuum the units or ask a professional to clean.


  • Connect the dryer to vent outside;
  • Remove lint every time you use the dryer;
  • Do not hang the clothes inside to dry. Wipe the detergent and washing machine after use.


  • Check that the fan bathroom wicks outside, not in the attic;
  • Operate the fan every time you take a shower. Let it run for a few minutes;
  • Take short showers;
  • Keep clean and dry surfaces that are wet as the walls of the tub or shower;
  • If the floor of the bathroom is carpeted, remove it;
  • Check for signs of water leakage;
  • Keep drains in good condition are removing debris that may be present.

To clean the drains

  • Pour a handful of baking soda;
  • Add a cup of vinegar;
  • Replace the cap;
  • Let the vinegar and baking soda for 20 minutes;
  • Let the water flow in the pipe;
  • If the hose is still clogged, use a plunger ferret.


  • If the hood above the stove is connected directly to the outside, use-in when cooking;
  • Avoid letting the water boil for longer than necessary;
  • Keep drains in good condition. Follow the steps in "Bathroom" above;
  • A tray or drain pan at the bottom of your refrigerator. Pull the refrigerator to clean the tank. At the same time, vacuum the coils on the back;
  • Check for leaks under the kitchen sink;
  • Take out the garbage every day to prevent the spread of odors.

Wardrobes and bedrooms

  • Discard clothing or stored items you do not use anymore. By keeping tidy wardrobes, it facilitates the flow of air and mildew are jammed.

Other parts of the housing

  • During the warmer months, make use of a dehumidifier to lower the humidity. Close the windows when the dehumidifier works;
  • When family or friends visit you, ask them to remove their shoes;
  • Vacuum often. If you buy a vacuum cleaner, look for a model equipped with a HEPA filter;
  • Clean hard floors with a damp mop;
  • Do not put in your condominium furniture, clothes, books or other items that have been stored in a damp place;
  • Reduce the number of plants in the house, since the land promotes the growth of mold.

Outside the housing

(Contact your Board of owners)

  • Check the roof or walls to detect any water infiltration;
  • Make sure the gutters, downspouts and extensions are connected and fill out their function;
  • Fix problems in the shortest possible time.

Mold prevention

Frequently Asked Questions about mold

The air inside appears dry. Should I wet?

Before you make the air more humid, measure the relative moisture content. The air feels dry does perhaps not. It may be contaminated with mold. High (greater than 50%) relative humidity promotes mold growth and the appearance of mites. Moisture in the air can lead to condensation on colder exterior walls and promote mold growth.

If your doctor recommends using a humidifier in your child's room at night, monitor the relative humidity. Run the humidifier only when needed. In the morning, let it dry. Empty and clean the humidifier after use.