Attic Mould Removal & Ventilation Etobicoke

Attic Mould Remediation

YAREX Renovation & Restoration, a licensed and insured Etobicoke contractor, removes attic mould (mold) across Toronto and the GTA and fixes the ventilation problem that caused it. We clean and seal the affected roof sheathing under containment, reroute bathroom fans outside, open blocked soffits, air-seal the ceiling below and top up insulation. Most attics cost about $4,000 to $10,000. Assessments are free.

Discuss your restoration

Planning range$4,000 – $10,000

Typical on-site time1–3 days

What’s included

Attic inspection & moisture source diagnosis
Containment & HEPA air scrubbing
Sheathing cleaned, treated & sealed
Bath fans ducted to the exterior
Soffit baffles & roof ventilation
Air sealing & insulation top-up

Attic mould remediation across Etobicoke, Toronto and the GTA

Attic mould is the most common mould problem we see in GTA houses, and the most commonly misdiagnosed. It is not a roof leak and it is rarely dangerous in the short term, but it does not go away on its own, it gets worse every winter, and it will be found by the next home inspector. YAREX removes it from our Etobicoke base across Toronto, Mississauga and the rest of the GTA, and fixes the reason it grew.

Signs of mould in your attic

Black or grey staining on the underside of the roof sheathing, often heaviest on the north side and near the eaves
Frost on nail tips poking through the sheathing in January and February, then drips on the insulation when it thaws
Ice dams along the eaves
A musty smell on the top floor, or near the attic hatch
A bathroom fan that you can hear but that has no vent on the roof or wall

Toronto’s 1950s to 1970s bungalows and two-storeys are the classic case: minimal attic ventilation, bathroom fans added later and vented into the attic, and decades of ceiling air leaks.

Attic ventilation is the real fix

An attic stays dry when outside air flows in at the soffits, up under the roof deck and out at the roof or ridge vents. Most mouldy attics we open have lost that flow: insulation pushed into the eaves, a bathroom fan blowing into the roof space, or air leaking up through pot lights and the hatch. That is why attic ventilation work, not just cleaning, is part of every job. The full explanation is in why Etobicoke attics grow mould, and how ventilation fixes it.

How the work runs

Inspection. We confirm it is mould, map how much sheathing is affected and find the moisture source. See mould inspection.
Protection. The attic hatch and the room below are sealed off, and HEPA air scrubbers run throughout the work.
Cleaning. Affected sheathing and framing are HEPA-vacuumed and cleaned back to sound wood, then treated.
Sealing. A mould-resistant encapsulating coating is applied to the cleaned surfaces.
Fixing the cause. Bathroom fans are ducted to the exterior, soffit baffles installed so air can flow, the ceiling below is air-sealed at fixtures, hatches and top plates, and insulation is topped up where it is thin or contaminated.
Documentation. Before-and-after photos and a written summary of what was found and fixed.

Most attics take one to three days.

Attic mould remediation in Etobicoke, Oakville and Mississauga

Most of our attic work is in the postwar bungalows and two-storeys of Etobicoke, Mississauga and Oakville, where small attic vents and later bathroom additions are common. We also work across Toronto and the rest of the GTA.

What it costs

Attic mould remediation typically runs $4,000 to $10,000 in the GTA. Where you land depends on how much of the roof deck is affected, whether insulation has to come out, and how much ventilation work the house needs. Sheathing that has actually rotted needs replacing from the roof side and is priced separately. Every quote is fixed-price and itemized, plus HST.

Why YAREX

Licensed and insured, with remediation and building work under one roof, so the ventilation, ducting and insulation are done by the same team that cleaned the attic, and the fix is ours to stand behind. Assessments are free. Call +1 343-947-2298 or visit 6 Hagersville Ct, Etobicoke.

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Where we work

Attic Mould Remediation from our Etobicoke base, across Toronto and the GTA:

Questions, answered.

What causes mould in an attic?

Moisture from inside the house. In winter, warm humid air leaks into the attic through ceiling fixtures, attic hatches and wall top plates, or is blown there by a bathroom fan that was never ducted outside. It condenses on the cold underside of the roof sheathing, and mould grows on the wet wood. Blocked soffit vents make it worse by stopping the airflow that would carry that moisture out.

How much does attic mould remediation cost in Toronto?

Most attics run about $4,000 to $10,000, including cleaning and sealing the sheathing and correcting the ventilation. A small area around one bathroom fan sits at the low end; a whole roof deck with insulation replacement and new vents sits at the high end. Replacing sheathing that has rotted, not just stained, is priced separately because it is roofing work.

Is attic mould dangerous?

Attic mould is usually less of a direct exposure than mould in living space, because the attic is separated from the house. But the air leaks that let moisture up can also let spores and odour down, and wet sheathing eventually rots, which is a roof problem. It also comes up in almost every Toronto home inspection, so it affects a sale.

Does home insurance cover attic mould?

Rarely. Attic mould is almost always caused by ventilation or air leakage built up over years, which Ontario policies treat as maintenance and generally exclude. The exception is mould from a sudden covered event, such as roof damage in a storm that let water in. We document the cause either way, which is what your insurer will ask about.

Will the mould come back after remediation?

Not if the cause is fixed. Cleaning sheathing without correcting airflow fails by the following winter, which is why every YAREX attic job includes the ventilation work: fans ducted outside, soffit baffles, air sealing at the ceiling and enough insulation to keep the sheathing cold and dry. We photograph before and after, and you get the documentation.