Mould Removal & Remediation in Ottawa
Find, contain, and remove mould at the source.
Ottawa Site Restoration removes mould from homes and businesses across Ottawa and Gatineau. Mould removal, also called mould remediation, means finding the water feeding the growth, containing the area so spores do not spread, removing material that cannot be cleaned, and drying what is left.
Mould and mold are the same word, Canadian and American spelling, and the job is identical either way. Health Canada publishes a size chart for deciding who does it: three patches or fewer totalling under one square metre is usually a homeowner job with the right mask and gloves.
A single patch larger than three square metres needs a professional assessment first.
How we remove mold from your Ottawa home
When you call Ottawa Site Restoration, we schedule a visit to your home or business in Ottawa or Gatineau. We start by locating the moisture source that is feeding the mould. We then contain the affected area to keep the mould from spreading while we work.
Next, we remove the mould at the source. After removal, we dry what is left. This process is available for homes and businesses across Ottawa and Gatineau. For a free quote, call (613) 852-4059.
How big is the mould problem?
| Size | Area | What Health Canada's guidance says |
|---|---|---|
| Small | Under 1 m² (about 10 sq ft) | Three patches or fewer totalling under one square metre. The occupant can clean it with proper precautions: an N95 mask, goggles and gloves. |
| Medium | 1 to 3 m² (about 10 to 32 sq ft) | More than three patches, or a total between one and three square metres. Can usually still be do-it-yourself work, though an expert assessment is recommended. |
| Large | Over 3 m² (about 32 sq ft) | A single patch larger than three square metres needs a professional. |
Ottawa's Mold Remediation Crew
We're a local, junk-removal-led crew serving Ottawa and Gatineau. What started with a truck has grown job by job, because when drywall and wet carpet need to go, they go on the same truck.
For water and mould claims, we document the damage, photograph the work, and provide the invoices your insurer needs. Expect a free quote, no hidden fees, and zero pressure. Same-day and next-day service available. Call (613) 852-4059.
What Our Customers Say
“A unit flooded overnight. They were on site the same morning, dried it out, handled the mould, and sent paperwork my insurer actually accepted.”
Insurance-Friendly Mold Remediation
When a claim is open, we can coordinate directly with your adjuster to keep the claim moving. You also get the list of what was wet and why, so everyone knows exactly what happened. You get a clear quote before we start, with no hidden fees and no pressure.
Key takeaway: We work with your adjuster and give you the facts, so the claim stays straightforward.
What we handle.
Mould thrives where moisture lingers, and painting over it never solves the problem. We locate the source, contain the affected area, and remove mould-damaged material safely so spores do not spread through the home. Then we treat and dry the space so it does not come back.
One crew handles it from start to finish: the cut drywall, bagged material and wet carpet leave on our own truck, not on a second contractor's schedule. We work across Ottawa and Gatineau, including Kanata, Barrhaven, Orleans, Nepean and Gloucester. Call or text (613) 852-4059 with a photo. We will tell you whether it is a job for our crew or one Health Canada's size chart leaves to you.
- Inspection to trace mould back to its moisture source
- Containment and safe removal of affected materials
- Air scrubbing and treatment of salvageable surfaces
- Guidance on fixing the leak or humidity that caused it
Everything the job covers.
Remediation is four things anywhere: find the water, contain the area, remove what cannot be cleaned, dry what is left. In Ottawa two of the usual water sources run on the calendar: winter condensation on cold foundation walls, and the spring melt working into cracks.
With this crew the end of the job is different too. The tear-out goes out on our own truck, and the clearance test does not: Health Canada suggests a separate firm runs that after extensive cleanup, and we say so up front.
Finding the water first
Mould is a moisture problem wearing a costume. Health Canada's residential guideline lists four usual causes: condensation from excessive humidity, lack of ventilation or low temperature; water leakage such as a broken pipe; water entering through a leaking roof or a cracked basement; and a flood.
Its 2023 guide to addressing moisture and mould indoors adds that mould will begin to grow in an area with excessive moisture within 48 hours. We trace the source before scoping removal, because remediation that leaves the water in place is a repeat visit.
Containment sized to the job
The Environmental Abatement Council of Canada's mould abatement guideline, written to help meet duties under Ontario's Occupational Health and Safety Act, sets three levels by area. Under 10 square feet is small scale: dust suppression, a drop sheet, HVAC shut down.
Ten to 100 square feet is medium and calls for a sealed polyethylene enclosure held under continuous negative pressure, a minimum of 5 Pascals and at least four air changes an hour. Over 100 square feet is large scale and needs a site-specific plan from a health and safety professional.
Removing what cannot be cleaned
Non-porous surfaces such as glass, tile, metal and vinyl can be washed. Porous material usually cannot: Health Canada says to discard mouldy fabrics, carpet and cushions, and that a mouldy mattress cannot be properly cleaned.
On building materials the abatement guideline says to cut porous substrate such as drywall and ceiling tile back at least 30 cm past the edge of visible growth, because the edge you can see is not the edge of the colony. Sealing or painting over it is not a substitute, and Health Canada's markers of a qualified company include prioritising removal over sealing or chemical treatment.
Drying, then haul-away
Removal is not the end of it. Wet material has to leave the building and the structure has to be dried, and Health Canada recommends a dehumidifier wherever condensation shows on cold surfaces or relative humidity sits above 50 percent. Junk removal is our core service, so the bagged material, cut drywall and ruined carpet go on the same truck instead of waiting for a second contractor.
What we do not do, said plainly
We are a removal and cleanup crew. We are not indoor air quality consultants, we do not run clearance sampling, and we do not write the site-specific work plan a large-scale job needs. Health Canada suggests that where extensive cleanup involves structural elements, a separate firm handle the post-remediation clearance study. Where your job needs that, we will say so rather than quote around it.
Start to finish.
Tell us what you can see, and we size it
Call or text (613) 852-4059 and describe it, or send photos. Then we walk the space and size the affected area against Health Canada's chart and the abatement levels above. If you land in the small or medium band, that is work you can do yourself with an N95, goggles and gloves, which is Health Canada's own minimum kit, and we will tell you so.
Contain before anything is disturbed
Poly sheeting with taped seams, HVAC shut down and adjacent diffusers sealed, and negative pressure where the size calls for it. Disturbing mould without containment is how a bathroom problem becomes a whole-house problem.
Remove, clean, dry
Porous material comes out and is bagged at the work area, non-porous surfaces are washed and dried, then air movers and dehumidifiers run until the substrate is dry rather than until it looks dry.
Haul it out and hand you the moisture list
Everything removed leaves on our truck, the part most remediation quotes price separately. You also get the list of what was wet and why, because the leak, the grading or the humidity is what decides whether the mould comes back.
What an Ottawa homeowner or landlord should know first.
The signs, including the mould you cannot see
Health Canada's guide to addressing moisture and mould indoors, published January 2023, lists what to look for: stains or discolouration on floors, walls, window panes, ceiling tiles, fabrics and carpets. The moisture feeding it leaves marks of its own: peeling paint, wrinkled wallpaper, cracks in plaster, warped wood, and efflorescence, the white chalky crust on basement concrete. A strong, musty smell with nothing visible is the other sign.
In that case Health Canada's advice is to consult a professional about hidden mould, the kind growing inside a wall cavity, under flooring or behind a finished basement panel. If the stain started with a leak or a flooded basement, the water comes first, and our water damage restoration page covers that half of the job.
Who should stay out of the room
Health Canada says people living with mould and damp are more likely to have eye, nose and throat irritation, coughing and phlegm build-up, wheezing and shortness of breath, and worse asthma symptoms. It names who is at greater risk: infants, children, seniors, pregnant people, and anyone with a respiratory condition such as asthma.
Its advice is that they should not be in or near the area while mould is cleaned up, and that pets stay away too. So tell us who lives in the house when you call, because it changes how the work area is sealed off. Symptoms are a question for a physician. The removal still has to happen.
Renting in Ottawa: the law puts the repair on the landlord
Health Canada's first step for a renter is to speak to the property owner about any moisture or mould problem. Do it in writing and keep a copy. If nothing happens, Ontario's Residential Tenancies Act, 2006 is the lever. Section 20(1) makes a landlord responsible for keeping a rental unit in a good state of repair and fit for habitation, and for complying with health, safety, housing and maintenance standards.
Section 20(2) says that holds even if the tenant knew about the problem before signing. A tenant can apply to the Landlord and Tenant Board under section 29, and under section 30 the Board can order the repairs done within a set time, reduce the rent, or order the landlord to pay for belongings the problem damaged.
The Board's own guideline says it considers whether the tenant told the landlord before applying, which is why the notice should be in writing.
The quicker route for an Ottawa tenant: 3-1-1
The City of Ottawa also takes tenant complaints about building maintenance and water problems, and the route is a call to 3-1-1. The City's Information for Tenants page says your contact details are not shared with your landlord, and you get a Service Request Number to track the case. A By-law Officer contacts you and inspects as needed. An immediate danger gets an Emergency Order.
Anything else gets a Notice of Violation or a Property Standards Order, and the landlord has at least 19 days to do the work, with no extension where there is a public health or safety risk. If it is still not fixed at re-inspection, the City can do the work and bill the landlord, or fine them.
The standard the officer applies is the Property Standards By-law quoted in the questions below.
Owning the rental: the same law, read from your side
If you are the landlord, section 20 applies whether or not the tenant saw the stain at the viewing, and an order from the Board or the City comes with a deadline. Whether the fix lasts depends on the water. A leaking roof, a downspout emptying at the foundation or a bathroom with no working fan will grow it back after any cleanup.
Health Canada says every bathroom should have an exhaust fan, run for at least 30 minutes after a shower or bath, and that a range hood should be used when cooking, on its highest setting if possible. Fix the source, then book the removal.
Mold in Gatineau runs on Quebec's rules
Cross the river and the renter's law changes. The Residential Tenancies Act is Ontario's, and the Property Standards By-law is Ottawa's. In Gatineau, rental disputes go to Quebec's Tribunal administratif du logement.
The Tribunal describes a dwelling unfit for habitation as one in a condition that is a serious danger to the health or safety of its occupants or the public, and it lists the presence of mould or fungus (moisissure, in French) and excessive humidity among its examples. A tenant can ask it to order the work, lower the rent, award damages or end the lease.
A tenant who leaves a dwelling that has become unfit has to notify the landlord before leaving or within 10 days after. Health Canada's size chart and cleanup advice are federal, so those read the same on both sides.
Does home insurance cover mould removal?
Look at the water first. The Insurance Bureau of Canada, the industry association for most of Canada's home, car and business insurers, puts the sudden and accidental escape of water from plumbing, heating, sprinkler or air conditioning systems, or from a domestic appliance, on its list of insured perils. Gradual deterioration it treats as natural and expected, and not an insured peril.
Sewer backup and overland flooding are optional add-ons bought separately, and IBC counts spring thaw as overland water. So a burst supply line and a slow drip behind a vanity can grow the same mould and end in two very different claims. Before anything is torn out, photograph the damage and check with your insurer, as IBC's claim steps advise.
Our guide on whether home insurance covers mould in Ontario lists the exclusions to look for and what to do if a claim is refused. If the policy will not pay, the guide to what mould removal costs in Ottawa compares the prices two mould companies publish. Neither is ours, and we quote after seeing the space.
Ottawa basements make their own water
Two local cycles feed this. Through winter, warm indoor air meets cold surfaces at rim joists, window frames and uninsulated foundation walls, and condensation forms on the cold side. Health Canada's advice is to hold indoor relative humidity between 30 and 50 percent and run a dehumidifier as soon as condensation shows.
Then in spring the melt arrives at a foundation that spent months freezing and thawing, and finds every crack that opened. One City of Ottawa rule is worth checking before you spend anything on the mould itself. Property Standards By-law No. 2013-416 requires roof drainage to discharge at least 1.2 metres, four feet, from the building where physically possible.
A downspout emptying at the foundation is both a by-law issue and a standing invitation to the wet wall under the mould. If the basement has already flooded, our flooded basement guide covers the first hour, the first 48 and what insurance pays.
What drives the price.
Mould work is priced on the size of the affected area and the containment that size forces, not on the room it sits in.
What moves the number: how many square feet of material are genuinely affected, whether the growth is on non-porous surfaces that can be washed or in porous material that has to come out, whether a sealed enclosure and negative pressure are required, how much drying the structure needs, and access, since a crawl space costs more in labour than an open basement wall.
Budget separately for two things outside our quote: repairing the leak or humidity that caused the growth, and, on a large job, independent clearance work. We look at the space and quote it up front. Call (613) 852-4059.
Seasonal and climate considerations.
Winter: cold walls and condensation
Environment and Climate Change Canada's 1981 to 2010 climate normals for the Ottawa Macdonald-Cartier airport station put January's mean daily temperature at minus 10.3 °C, and the daily high stays at or below zero on about 78 days a year. That cold is what turns window panes, rim joists and foundation walls into the cold surfaces where indoor moisture condenses.
Health Canada's guide adds two habits for this season. Keep curtains and blinds open so warm air reaches the glass, and dry window frames and sills daily so the water does not drip and grow mould.
March and April: freeze, thaw, then the melt
Ottawa gets about 223 cm of snow in a normal year. ECCC's normals show roughly 25 cm still on the ground at the end of February and under 5 cm by the end of March, so most of what is left melts in one month.
In March the low drops to zero or below on about 27 days and the high climbs above zero on about 21, which means many March days freeze at night and thaw by afternoon. Health Canada lists snow melt among the weather floods behind indoor mould.
Its fix starts outside: slope the grade away from the house so rain and snowmelt drain off, and keep downspout outflow running away from the building.
July to September: the wettest air of the year
Summer is when Ottawa air holds the most water. ECCC's normals put the average 6 a.m. relative humidity at 84 percent in July, 88 in August and 90 in September, and July air carries more than six times the water vapour of January air.
Health Canada's guide says to run a dehumidifier in damp areas such as basements, year-round if necessary, with the windows closed while it runs, and notes that air conditioning also brings moisture down. Store basement items in plastic bins with lids, and never put cardboard boxes straight on the basement floor.
Timing the work
The outside fixes, regrading soil against the foundation and moving a downspout, are outdoor work. The same ECCC normals put the average last spring frost at about April 30 and the first fall frost at about October 7. The removal does not wait for a season.
Health Canada says mould starts to grow within 48 hours in an area with excess moisture, so a wet basement in February is a February job. Call or text (613) 852-4059 and we will size it against Health Canada's chart before anything is cut.
Mould Remediation, answered.
Still unsure? Call or text (613) 852-4059 and we will tell you straight.
Often, yes. Health Canada's decision chart calls an area small when there are three patches or fewer totalling under one square metre, and says a small area can be cleaned by the occupant with proper precautions. Medium, meaning more than three patches or a total between one and three square metres, can usually still be do-it-yourself work, though an expert assessment is recommended.
A single patch larger than three square metres needs a professional.
Up to a point, you can. Health Canada's size chart leaves small areas, and most medium ones, to the occupant wearing an N95 mask, goggles and gloves. Anything bigger, including any single patch over three square metres, is professional work, and that is what our crew does: containment, tear-out, drying and the haul-away.
Where extensive cleanup reaches structural elements, Health Canada suggests a separate firm run the clearance study afterwards, and we will say when your job needs one. In a rental the repair is the landlord's, and an Ottawa tenant can call 3-1-1 if it does not happen. Send a photo to (613) 852-4059 and we will tell you which of these you are looking at.
Health Canada's Residential Indoor Air Quality Guideline for moulds, published 2007-03-31, is explicit that its recommendations, control the humidity, repair the water damage, clean the mould thoroughly, apply regardless of the mould species found growing in the building. Colour is not a diagnosis. Identifying the strain does not change what has to be removed, and no strain makes it safe to leave.
In most situations Health Canada does not recommend testing the air for mould. An air test cannot predict health effects and usually says little about the cause of the damage. The exception it allows is narrow: where concerns remain unexplained after a proper visual inspection, especially with a history of flooding or leaks, a qualified professional may recommend a non-viable spore test to locate hidden growth in cavities.
If a company leads with a test, ask what decision the result will change.
Health Canada's guidance says not to use bleach to clean up mould. The method it publishes for washable surfaces is a cloth with an unscented soap solution, then dried completely and quickly. Bleach also does nothing about the reason the mould is there. If the moisture stays, the growth comes back whatever you wiped it with, and porous material that absorbed water still has to come out.
Health Canada publishes the checklist, so use it on every quote you get, ours included. Ask what certification and training the company holds, since Health Canada names IICRC certification as one marker. Ask whether the liability insurance specifically covers mould removal, and ask to see it.
Ask whether they remove damaged material or seal and chemically treat it, because Health Canada favours removal. And get the inspection and cleanup procedures in writing before work starts.
The City of Ottawa's Property Standards By-law No. 2013-416 is the lever. Section 19 requires interior floors, ceilings and walls to be kept free from dampness entering through an exterior wall, a roof, or a cellar, basement or crawl space floor.
Its residential walls and ceilings section requires finishes to be free of holes, cracks, loose coverings, mould or other defects. The by-law text is published on ottawa.ca, and enforcement is a City matter, not a contractor one.
It is priced on the size of the affected area and the containment that size forces, not on the room it is in. The number moves with how many square feet are affected, whether the growth sits on surfaces that wash or in drywall and carpet that has to come out, whether a sealed enclosure under negative pressure is needed, and how much drying follows.
Two costs sit outside a removal quote: fixing the leak or humidity behind it, and independent clearance work on a large job. We look at the space and quote it before starting. Call (613) 852-4059.
Yes, on both sides of the river. Health Canada's size chart and its advice on what to wash and what to throw away are federal guidance, so they read the same in Gatineau as in Ottawa. The City of Ottawa's Property Standards By-law is the part that stops at the river: it is an Ottawa by-law, so a Gatineau rental is not governed by it.
A strong, musty smell with nothing visible is the main one, and Health Canada's advice in that case is to consult a professional about hidden mould. The other signs belong to the moisture: stains or discolouration, peeling paint, wrinkled wallpaper, cracks in plaster, warped wood, and a white chalky crust on basement concrete.
Behind a finished basement wall or under flooring, growth can spread well before any of those reach the surface.
Health Canada's advice names who should keep away: infants, children, seniors, pregnant people and anyone with a respiratory condition such as asthma should not be in or near the area where mould is being cleaned up, and pets should be kept away too.
Sealing the work area with poly sheeting, and holding it under negative pressure on a medium job, is what keeps the spores in that room instead of the rest of the house. Tell us who lives there when you book.
Because the moisture is still there. Health Canada says every bathroom should have an exhaust fan and that it should run for at least 30 minutes after a shower or bath, and its range for indoor relative humidity is 30 to 50 percent.
Paint over the stain without fixing that and it grows back through the paint. If the drywall behind it is soft or the patch keeps spreading, the material has to come out.
Yes, across the Ottawa-Gatineau region: Kanata and Stittsville in the west, Orléans and Cumberland in the east, Barrhaven, Riverside South and Manotick in the south, and Gatineau across the river. Mold or mould, it is the same job, and this page uses the Canadian spelling. Call (613) 852-4059 with your address and a photo of what you can see.
It depends on whether the mould is on a surface or inside the wall. Mold Inspection Canada's 2026 national price guide, read on 2026-09-30, puts mould on visible bathroom tile and grout at $500 to $1,500, and mould on the cavity side of a wall, with the drywall down and the framing dried for 5 to 14 days, at $5,000 to $15,000 for one room.
Those are that company's national figures, not ours. We look at the space and quote it before starting.
Black mould is not priced as a separate job. Health Canada's guideline says its recommendations, control the humidity, repair the water damage and clean the mould thoroughly, apply whatever species is growing, so the price follows the area, the location and what is behind the drywall.
If you want the species identified, Mold Inspection Canada says lab identification adds $100 to $200 to its inspection price, a figure read on 2026-09-30 that is its price, not ours. Health Canada treats every species the same way, so the result does not change what comes out of the wall.
It depends on how much area is affected, where it is and whether it has gone behind the drywall. Mold Busters lists average Ottawa costs of $1,500 to $2,500 for minor mould on a small area, $2,500 to $7,500 for a larger area or several rooms, and $7,000 to $15,000 or more once mould has gone deep into the building.
Mold Inspection Canada's 2026 national figure for a whole house is $10,000 to $30,000. Both pages were read on 2026-09-30, and none of these is our price.
Keep the moisture out, because Health Canada says mould begins to grow within 48 hours in an area with excessive moisture. Run the bathroom exhaust fan for at least 30 minutes after a shower and hold indoor relative humidity between 30 and 50 percent.
Fix the cause of any leak or damp wall as well, since Health Canada says that unless the moisture problem is identified and solved, mould will reappear.
Not bleach: Health Canada's guidance says not to use it to clean up mould. Not paint or sealant either. If the mould is underneath the paint the drywall will need to be removed and replaced, and painting over a stain without fixing the moisture lets it grow back through the paint. For washable surfaces, Health Canada's method is a cloth with an unscented soap solution, then dried completely and quickly.
The lasting fix in Health Canada's guidance is removing the water, not a product. It says that unless the cause of the moisture problem has been identified and solved, mould will reappear. So the order is: remove the growth, dry the structure, fix the leak or the humidity, and keep indoor relative humidity between 30 and 50 percent. Health Canada also says not to use bleach.
Yes. Mould is the Canadian spelling and mold is the American one, and both name the same growth and the same job. Health Canada writes mould, and so does this page. A search for mold removal in Ottawa is looking for the same work: find the water, contain the area, remove what cannot be cleaned and dry what is left. Call (613) 852-4059 with a photo.
Health Canada's guide to addressing moisture and mould indoors names neither. For a washable surface it says to scrub with a cloth and an unscented soap solution, then dry the surface completely and quickly. On a painted wall it also allows baking soda.
The one product it rules out by name is bleach. Whatever you wipe with, Health Canada says mould that comes back after cleaning usually means the moisture source is still there.
Nothing removes it for good in one wipe, because the stain is only the part you can see. Health Canada says that unless the cause of the moisture problem is identified and solved, mould will reappear. A small patch on tile or glass scrubs off with unscented soap and water, then gets dried straight away.
Mould under the paint on drywall, or in a carpet, does not wipe off at all: Health Canada says that drywall has to be removed and replaced, and mouldy carpet cut out and discarded.
Health Canada does not name a brand, and we will not either. Its method for a washable surface is a cloth or brush with unscented soap and warm water, then drying the surface completely and quickly, and it says not to use bleach.
The drying matters more than the bottle. Health Canada says mould begins to grow within 48 hours where there is excessive moisture, so a fixed leak and a dehumidifier do more than any cleaner.
Where these facts come from
Two authorities answering two different questions. Health Canada sets the size chart, the 48 hour figure and the advice on what can be washed and what has to be discarded; the City's Property Standards By-law sets the dampness and roof drainage conditions a building is held to, and enforcing it is a City matter rather than a contractor one.
The renter sections rest on three more: Ontario's Residential Tenancies Act and the Landlord and Tenant Board for the repair duty and the Board's orders, the City's tenant page for the 3-1-1 route and the 19 day minimum, and Quebec's housing tribunal for Gatineau, where neither Ontario rule applies. The seasonal figures are Environment and Climate Change Canada's 1981 to 2010 climate normals for the Ottawa Macdonald-Cartier airport station.
- Health Canada, Guide to addressing moisture and mould indoors read
- City of Ottawa, Property Standards By-law No. 2013-416 read
- Ontario, Residential Tenancies Act, 2006, sections 20, 29 and 30 read
- Landlord and Tenant Board, Interpretation Guideline 5: Breach of Maintenance Obligations read
- City of Ottawa, Information for Tenants read
- Tribunal administratif du logement, Unsanitary conditions read
- Environment and Climate Change Canada, Canadian Climate Normals 1981-2010, Ottawa Macdonald-Cartier Int'l A read
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