Mould Removal & Remediation in Ottawa

No. Mould is not one of the eleven designated substances under O. Reg. 490/09, and there is no Ontario regulation setting containment classes or clearance criteria for mould the way O. Reg. 278/05 does for asbestos. Mould work is governed by the general duty provisions of the Occupational Health and Safety Act together with industry guidelines. Any contractor quoting you a legally mandated mould clearance number is describing a guideline, not a regulation.

Sometimes, and less often than it is sold. Air sampling is useful for establishing a baseline in a dispute, for verifying work in a sensitive occupancy, or where growth is suspected but not visible. It is a poor substitute for finding the moisture source, and a clean air sample in a room with a wet wall cavity tells you very little.

On a small, non-porous surface with a known and corrected moisture source, surface cleaning is reasonable. On porous material like drywall or insulation, bleach wets the substrate and treats the visible face while the colonisation continues behind it. The material has to come out.

In an Ottawa building built before 1990, assume it is possible until sampling says otherwise. Drywall joint compound, vinyl floor tile and mastic, pipe insulation, and textured ceilings are all common asbestos-containing materials in the same assemblies where mould shows up after a leak. HMRS scopes both on one visit rather than discovering the second one after containment is already built for the first.

It depends on the cause and the policy. Mould arising from a sudden covered water loss is treated differently from mould arising from long-term seepage or deferred maintenance, and most policies say so explicitly. What helps a claim is documentation showing when the water event happened and what was done about it, which is a reason to document the dry-down properly rather than after the fact.

Usually not. Most occupied-building mould work is done by isolating the work area under negative pressure and shutting down the air handling that serves it. What needs deciding early is the route in and out for waste and whether any shared mechanical system connects the area to occupied space.

Removal is often the short part. Drying to a documented target is what sets the schedule, and it depends on the material, the extent of saturation, and how long the assembly was wet before anyone called. HMRS gives a stage-by-stage schedule at scoping rather than a single number.

Warm humid air leaking from the living space into a cold attic and condensing on the underside of the sheathing. It is a ventilation and air-sealing problem more often than a roof leak, which is why cleaning the sheathing without correcting the air path produces the same result the following winter.