Overview: Mold Inspection & Testing
Mould is a symptom. Something got wet and stayed wet long enough to grow. The companies in this category find out why: where the water comes from, how far it has spread and what it has damaged. Removing it is a separate trade, and ideally a separate contract.
In a Canadian house, the cold does much of the damage. Warm indoor air meets a cold surface behind the finish, condenses and feeds growth inside a wall that looks fine. Basements, rim joists and attics above ice dams are the usual places. A good inspector reaches for a moisture meter and a thermal camera before any swab.
Be wary of anyone who leads with an air test. Health Canada doesn't recommend testing the air for mould in most homes. There's no exposure limit to compare a result against, and the test rarely explains the cause. Its advice is to fix the moisture, clean up the growth, and bring in a qualified professional for large areas.
Our listings show what each inspection company states on its own website. Use the province and city lists below to find inspectors working your area.
Frequently asked questions
Do I need a test if I can see it?
Usually not, at least to prove it's there. Visible growth is growth, and Health Canada doesn't recommend air testing in most homes. What you need is the diagnosis: where the water gets in, how much of the wall is wet, and whether growth has spread out of sight. Get professional help for a patch about the size of a sheet of plywood or larger, for mould that returns after cleaning, or after a flood with contaminated water.
Can I clean a small patch of mould myself?
Yes, if it's small and on a surface you can wash. Health Canada says to scrub with an unscented soap solution and dry the spot completely, wearing goggles, a disposable respirator and household gloves. Skip the bleach, which it specifically advises against. Mould under paint means the drywall comes out, and mouldy fabrics usually go in the garbage. If it comes back, the moisture problem is still there.
What can a lab result actually tell me?
Which spore types were in the sample and roughly how many. That's all. Health Canada says there's no exposure limit for mould, so a count can't tell you your health risk. It sees a narrow role for air tests: when a professional has already inspected and concerns remain, often after a flood or a leak into wall cavities. Even then, the count can't date the growth or speak for rooms nobody sampled.
What if the inspector finds vermiculite insulation in the attic?
Leave it alone. Health Canada says some vermiculite insulation may contain asbestos, and that it poses very little risk while it stays sealed off from the living space. Don't store things in that attic or let kids play up there. Seal gaps around the hatch, light fixtures and outlets. If you're renovating or it has to come out, hire a trained asbestos professional. Never remove it yourself.
What else do these companies test for?
Radon is the big one. Health Canada says every home should be tested, using a long-term test that runs for months, ideally through the heating season, on the lowest level you use regularly. If you hire someone, it recommends a professional certified under the Canadian National Radon Proficiency Program. Asbestos is the other. Before renovating around old insulation, siding or tiles, Health Canada recommends a professional test.
