Mould remediation
Mould Remediation After Water Damage
Scoped by area against the EACO levels, contained before anything is disturbed, and never started in a pre-1990 building until the asbestos question is answered.
Mould after a water loss is a consequence, not a cause. Removing it without finding and fixing the moisture that fed it is money spent on a result that regrows, and any scope that does not start with the water source is incomplete.
The levels, and the thresholds that set them
Ontario abatement work is done to the EACO Mould Abatement Guidelines, Edition 3 (2015), which set three levels of work scaled to the size of the affected area. The thresholds are specific, and they are what an honest scope is built on:
| Level | Affected area | What it requires |
|---|---|---|
| Level 1 | Under 10 ft² (1 m²) | Small-scale procedures, HEPA vacuum, wet wiping, no enclosure |
| Level 2 | 10–100 ft² (1–10 m²) | Contained abatement — the work area is isolated |
| Level 3 | Over 100 ft² (10 m²) | Full enclosure under continuous negative pressure |
At Level 3 the guidelines call for a minimum negative pressure of 5 Pascals — 0.02 inches of water column — and at least four air changes an hour inside the enclosure, with HEPA-filtered air discharged outside the building. Those are numbers a contractor can be held to, and asking which level a quote is priced at is the fastest way to compare two estimates that look different.
The step that comes before any of it
Before material is disturbed in an older building, somebody has to establish whether it contains asbestos. In Ontario this is not a courtesy. Asbestos on construction projects and in buildings and repair operations is regulated under O. Reg. 278/05, and before an owner arranges demolition, alteration or repair, a report must be prepared stating whether material that may be disturbed is asbestos-containing, describing its condition and location, and stating whether it is friable — and the owner must give a copy to any prospective constructor.
Around six in ten dwellings in the Collingwood area predate 1990 and roughly one in five predate 1960, so this applies to a large share of the buildings we are called to. Vinyl floor tile and its adhesive, some plasters and textured finishes, and older mechanical insulation are all candidates. An emergency does not suspend the requirement, and a crew that opens a 1955 basement wall the same afternoon without asking the question has skipped a legal step, not a cautious one.
Why testing is usually not the first thing to buy
Air sampling has real uses — a dispute, a tenancy, a sale, an occupant with a diagnosed sensitivity, or verification after a Level 3 job. What it is poor at is answering "do I have a problem", because the answer is already visible and the remediation does not change based on the species. If you can see it and you know where the water came from, the money is better spent removing it.
Mould removal in a Collingwood basement
The commonest job we scope in this area is a finished basement with a recurring water entry, where the growth is on the back of the drywall and the face looks fine. It is found by opening a small inspection cut low on the wall, and it is almost always larger than the visible staining suggested, which is why a scope written from what is visible on the surface is a scope that gets revised on site.
Attic mould after an ice dam leak
Attic growth after a winter leak is usually on the underside of the sheathing, and it is usually a ventilation problem as much as a water one. Cleaning it without correcting the airflow that produced the condensation is a job that gets repeated. See ice dam and roof leak damage for why the same houses do this every winter.
FAQ
Mould remediation — common questions
Is there a legal mould limit in Ontario?
There is no numerical limit for mould in a home in Ontario, and anybody quoting you one is quoting something else. What exists is guidance on how the work is performed — the EACO guidelines and their three levels — and separate law covering the designated substances an older building may contain. That is why a good quote describes the level, the containment and the boundary of the work rather than a target number.
Can I just use bleach?
On a hard, non-porous surface with a small amount of growth, cleaning works and we will say so rather than sell you a containment. On porous material — drywall, insulation, particleboard — the growth is through the material, not on it, and surface treatment changes the colour rather than the condition. The material has to come out.
How much does mould remediation cost?
It is scoped by the affected area, not by the room, and the EACO level is the biggest single driver. A Level 1 area under 10 ft² is often a few hundred dollars alongside other work. A Level 3 job over 100 ft² needs a full enclosure under negative pressure and is priced accordingly. Ask any quote which level it assumes.
Talk to a Collingwood water damage restoration company
Tell us where the water is, where you think it came from, and when you first saw it. Those three answers decide almost everything — whether this is an afternoon of drying or a scope with removal in it, whether it is likely to be an insurable event, and whether the honest advice is to stop reading and shut the water off first.