Black mold removal in Calgary

“Black mould” is what almost everybody types into a search bar, and it is worth being straight about what it means. It is not a species. Dark staining on a basement wall or behind a bathroom vanity can be any one of a long list of moulds, and several harmless things that are not mould at all. Colour tells you almost nothing. A laboratory tells you what it is, and a moisture reading tells you whether it is coming back.

We are also not going to tell you what mould has done to your health. That is a doctor’s question, not a contractor’s, and any contractor who answers it is selling you something.

Find the water first

Mould is a symptom. It grows where there is moisture, and it will regrow in the same spot within months if the moisture is still there. So the first job is not scrubbing — it is finding the source. In Calgary that is usually one of a short list: a failed washing machine or dishwasher line, a hot water tank at the end of its life, grade sloping back toward the foundation, a window well with no drainage, an ice dam pushing meltwater under the shingles, a bathroom fan venting into the attic instead of outside, or a basement that floods every few years.

If the answer is a plumbing or roofing repair we will tell you, even when it means the remediation is smaller than you expected.

How the work runs

The affected area is contained — poly over the openings, HVAC shut down and registers sealed, negative air running so spores move into the containment instead of through the house. Porous material that has been wet and grown mould through it is removed rather than cleaned: drywall, insulation, carpet, underlay, ceiling tile, particleboard. Non-porous surfaces are cleaned and HEPA-vacuumed. Then the structure is dried properly and moisture-metered rather than eyeballed, because framing that still reads wet will grow mould again behind new drywall.

One important overlap: in a pre-1990 building the drywall you are cutting out may contain asbestos in the joint compound. A mould job and an asbestos job are two different containments with two different rule sets, and hitting the second one halfway through the first is how a job doubles in price. We check before we cut.

What we do not do

We do not do independent mould assessments or write the kind of report you would use in a dispute with a landlord, a condo board or an insurer. That is a registered occupational hygienist’s work, and it should come from someone who has no financial interest in the removal. If that is what you need, we will point you at one rather than take your money for the wrong thing.

What it costs

Mould remediation is quoted in writing after a site visit, because the price follows how much material has to come out and how much drying the structure needs, neither of which can be judged from a photo. We publish our asbestos prices in full on the pricing page and we quote mould the same way: itemised, fixed, in writing, before anything starts.

Where we work

Mould removal across Calgary and the surrounding communities, including Calgary, Airdrie, Cochrane, Okotoks, Chestermere, Strathmore, High River and Red Deer. See also our mold remediation page and what to do about black mould in a basement.

Frequently asked questions

Is black mould more dangerous than other mould?

Colour does not identify a species, and we are not qualified to tell you what any mould has done to your health — that is a doctor's question. What we can tell you is that mould growing on wet building material should be removed under containment rather than scrubbed with bleach, whatever colour it is.

Can I just clean it with bleach?

On a hard, non-porous surface like tile or a tub surround, a small patch can often be cleaned. On drywall, insulation, carpet or particleboard, no — the growth is through the material, not on it, and bleach wets it further while leaving the roots behind. Porous material that has grown mould comes out.

Will it come back?

It will if the water source is still there. That is why we look for the source before quoting, and why a quote that covers only the cleanup is an incomplete quote. Sometimes the real fix is a plumber or a roofer and we will say so.

Do you test for mould?

We do not offer independent mould assessments or reports for disputes. That is an occupational hygienist's work and it should come from someone with no interest in selling you the removal. We will refer you to one.

Does insurance cover mould removal?

It depends on the cause and on your policy. Sudden and accidental water damage is often covered where long-term seepage is not. Call your broker before work starts, and read our note on water damage and insurance in Alberta. We document as we go so there is a record either way.