What does mold removal cost in Ontario?

Why there is no standard price

We do not publish a price list, because any single number would be wrong for most homes. Mold removal is priced on the work involved, and that varies widely. What follows explains what you are paying for so that a quote makes sense, and so that you can compare two quotes fairly.

What drives the cost

1. The size of the affected area

Health Canada describes mold as a small amount when there are three or fewer patches with a total area under one square metre. That is often a cleaning job a homeowner can do. Beyond that, the job grows with the area, and with how much of it is hidden inside walls or under floors.

2. Where it is

• Attics are awkward to work in and often need insulation removed.
• Basements often involve removing finished walls and flooring.
• Bathrooms and kitchens can mean removing tile, vanities or cabinets to reach it.
• Crawlspaces are slow, confined work.
• Ductwork needs specialised cleaning.

3. What has to come out

Cleaning mold off framing costs less than removing and replacing drywall, insulation, carpet or cabinets. The rebuild afterwards is often a larger cost than the remediation itself.

4. Containment

Proper remediation isolates the work area with plastic sheeting and negative air pressure through HEPA filtration. Larger and more contaminated areas need more of it.

5. Fixing the cause

A plumbing repair, a bathroom fan, attic ventilation, grading or a dehumidifier. Without this, the mold returns, so it belongs in the plan even if another trade does it.

6. Testing

If you want air or surface testing before or after, that is a separate cost. For verification, use an assessor who is independent of the remediation contractor.

What a good quote includes

• A description of the cause and what will be done about it
• The areas to be contained
• Which materials will be removed and which cleaned
• How the remaining structure will be cleaned and dried
• Disposal
• Whether clearance testing is included or recommended
• The rebuild, priced separately

Warning signs in a quote

• A price given over the phone without seeing the problem
• No mention of the moisture source
• No containment
• “Spray and leave” treatment of visible mold on drywall
• The same company testing, remediating and clearing its own work

Does insurance pay?

Often not. Many home policies exclude or limit mold. It is most likely to be covered when it results directly from a covered loss, such as a burst pipe, that was reported and dealt with promptly. Mold from long-term leaks, condensation or humidity is usually treated as a maintenance issue. Ask your insurer.

Lowering the cost

• Act early. Mold spreads while it has moisture.
• Fix the moisture source now, even before remediation.
• Small patches on hard surfaces can be cleaned with detergent and water.
• Get the scope in writing so quotes can be compared like for like.

Three typical jobs, compared

A bathroom wall behind a leaking shower. A small contained area. Tile and drywall come off one wall, the framing is cleaned and dried, the leak is repaired, and the wall is rebuilt and retiled. The rebuild is a large share of the total.

An attic with mold across the sheathing. No finishes to rebuild, but awkward access, a large surface area to clean, insulation that may need removing and replacing, and ventilation and air sealing corrections.

A finished basement after an old flood. The largest of the three. Containment across the space, removal of drywall, insulation and flooring along the affected walls, cleaning of framing and concrete, drying, a moisture fix, and then a full rebuild.

The same word, mold, covers all three.

Questions that change the price

• How many square metres are affected, including what is hidden?
• Is it on finished surfaces or bare structure?
• Can the area be isolated easily?
• Does the household need the space kept usable during the work?
• Is the moisture source fixed, or part of the job?
• Is independent clearance testing wanted?

Why the cheapest quote can cost more

A low price usually means something has been left out: containment, removal of contaminated materials or the moisture fix. Mold that is sprayed and left, or cleaned without the cause being fixed, comes back, and the second job is larger than the first.

Compare quotes line by line. If one contractor is removing drywall and another is not, ask each why.

Timing

Mold does not usually need an overnight emergency response the way a flood does, but it does not improve with waiting. If there is active moisture, deal with that immediately. The remediation can then be scheduled properly, which also gives you time to get more than one quote.

More: mold removal and remediation.