Health Issues

If you are having a problem with allergies then there’s a good chance there could be mould growing somewhere in your home. Common allergic reactions to mould include sneezing, sore eyes and a runny nose or nasal congestion.

Do you notice your allergic reactions are worse when you’re at home but you feel better when you go out? If so then it’s especially likely you could have mould. If you find that your allergies are worse in some other building, like your workplace, then there could be mould growing there instead.



When you have mould growing hidden away in your house, often a musty smell might be the only clue that it’s there.  Mould has a pungent smell. When it is confined to one area of your home, you may notice an unpleasant odor when you are in that area. Mould can sometimes live within the walls or behind wallpaper, and so you might not immediately associate the smell with mould. If you do notice an unusual persistent odor in your home, the culprit may be mould.

Don’t ignore mould odors if you can’t see any mould. You should thoroughly inspect your home before any mould problems get worse. Often times the only way to find mould is having air Quality testing done by a professional.



If you have had any long term moisture problems in your house it’s usually inevitable they will lead to mould beginning to grow. So if you know you’ve had some water problems in your home then it’s a pretty good sign you could have mould.

Some signs that you have a moisture problem include water stains or discoloration on walls, floors or ceilings in your house. Seeing these could be a clue that there is mould growing within or behind the material.

Another sign of a moisture problem is surface abnormalities like peeling, bubbling or cracking of the paint or wallpaper. If your walls are bowed, bulging or warped it probably means moisture has gotten into them. Another clue is if the surface of walls or other materials feel damp.


Mould from a leaking sink

The above signs of water problems in homes are usually created by leaks. However if you already know that you have had a water leak (such as leaking pipes or a leaking ceiling) then just that knowledge by itself, even if you don’t see signs of water damage, is a good sign that you might have mould growing in your house around the area where the leak was.

Mould growth from leaks can often be hidden. If the leak was behind a wall or other surface then any mould will probably be hidden behind the surface too. Even if the leak was not behind a surface there could still be mould hidden out of view behind a wall or other surface from water which seeped through.

Past Flooding

If your house has been flooded in the past then it’s likely that mould would’ve started to grow. Any mould would probably be growing in places where flood water remained the longest such as in the basement floods can often create mould growing out of view behind walls or under floors.



If you see a lot of condensation in your home then it’s a sign that you have a high amount of moisture and hence a sign that you could have a mould problem. Condensation will occur on surfaces such as glass windows or metal pipes. Mould could be growing where the condensation builds up and collects. Rusting indoor pipes are a sign that you could have a lot of condensation in your house.

Besides the fact that condensation creates a buildup of moisture for mould to grow on, condensation can also be a sign that you have a humidity problem in your home. A high humidity level can feed mould and it is another sign that you might have a potential mould problem.

Mould’s Favorite Places in Your Home

Fungi grow by releasing reproductive cells (spores) into the air, just as plants reproduce by spreading seeds. The airborne spores are invisible to the naked eye, which is a major reason mold is such a problem. It is not uncommon to find hundreds or even thousands of mold spores per cubic foot of indoor air. Spores are extremely small (1-100 microns)—20 million spores would fit on a postage stamp.

Spores can survive harsh environmental conditions, such as dryness, that do not support normal mould growth. In fact, many spores can lie dormant for decades until favorable conditions allow them to spring back to life.

Mould’s can be found almost anywhere; they can grow on virtually any substance, provided moisture and oxygen are present. There are Mould’s that can grow on wood, paper, carpet, tile, sheetrock, insulation, leather, fabrics, and foods.  Mould’s survive by digesting whatever substrate they are growing on, which is a real problem when it happens to be your floorboards. There is no way to eliminate all mould and mould spores from your indoor environment; the only way to control indoor mould growth is to control moisture. The most common indoor places for mould to take hold are damp areas, such as:

  • Bathrooms and kitchens, especially under sinks—particularly leaky ones
  • Behind or under appliances that hide slow plumbing leaks (refrigerators, dishwashers, washing machines, etc.)
  • Roof leaks
  • Around windows where condensation collects
  • High humidity areas of your home, such as basements

Often, the first sign of a mould problem is a “musty” odor. You are probably familiar with the smell of mildew—mildew is simply a variety of mould. You could also notice bowed or buckled floorboards, discolored carpet, a new water stain on your wall, or black or white specks—all signs you could be developing a mould problem. But what type of life form is mould?


How do I know if I have a problem?

  • In most cases, there is no need to measure the actual concentration of mould in your indoor air, or to determine the specific species of mould. You just need to find the mould and fix the problem.
  • Not all mould is obvious to find. It is important to check for mould anywhere that is damp, especially where water damage has happened.
  • Inspect your home for visible signs of mould or areas with too much moisture. Look for stains or discoloration on floors, walls, window panes, fabrics and carpets. See if you smell a musty “earthy” odor. If needed, contact an expert for help.



Ontario Mould Specialists can perform Air Quality Testing for Mould, Toxic VOCs, Carbon Monoxide, Carbon Dioxide, Methane, Asbestos & Radon



ontario mould specialists


ontario mould specialists