Zusashi Maintenance does not do water damage restoration. We clean commercial buildings. We wrote this because we get asked constantly by clients whose buildings we are already in, usually on a Monday. If you need the work done, we can point you at a contractor who does it — but this page is here to be useful whether or not you ever call us.
The number that decides everything: 24 to 48 hours
The Canadian Centre for Occupational Health and Safety advises cleaning up floods and spills immediately, within 24 to 48 hours, and states that rapid drying is what prevents mould growth.
That is not a comfort margin. It is the line between one problem and two.
| Time since it got wet | What you are dealing with |
|---|---|
| 0–24 hours | A water problem. Most materials still savable if drying starts now. The cheapest this will ever be. |
| 24–48 hours | Still a water problem, but the margin is gone. Drying needs to be running, not booked. |
| Past 48 hours | A water problem and a mould problem. Porous materials wet this long generally cannot be saved. Second contractor, second bill. |
So the useful question on discovering water is not how bad does this look. It is how long has it been wet. And that reframes which incidents are actually serious: a dramatic burst pipe found the same morning is often a better position to be in than a slow roof leak nobody noticed for five weeks.
What gets dried and what gets thrown away
This is where the money is, and where a weak contractor gives themselves away.
- Hard, non-porous surfaces — sealed concrete, tile, metal, glass, coated floors. Cleaned, dried, kept.
- Porous materials wet 48 hours or more — CCOHS is direct that flooring soaked by flood water should be removed and discarded, and the same reasoning covers soaked drywall, insulation, ceiling tiles and carpet underlay. Materials that hold water inside themselves do not reliably dry, and what stays inside feeds mould.
- Anything touched by contaminated water — porous material generally goes regardless of how long it has been wet.
If a proposal offers to dry everything in place several days after the event, either the contractor can see something you cannot, or you are buying a cheap job that leaves a problem inside the wall. Ask how they are deciding — the answer should involve moisture readings, not opinions.
Not all of it is clean water
CCOHS advises to always assume flood water is contaminated with sewage and chemicals. Three situations, handled very differently:
| What it is | What it changes |
|---|---|
| Clean supply water burst pipe, supply line, sprinkler head | Best case. Most materials savable if drying starts inside the window. |
| Water that picked something up through a ceiling, across a floor, from a dishwasher or washing machine | Porous materials become questionable. Treat as contaminated until somebody qualified says otherwise. |
| Sewage or drain backup | A different job. Not somewhere to put ordinary staff. Porous material goes. |
Two practical points from the same source: minimum respiratory protection for flood cleanup is an N95 or better, and carbon monoxide builds up quickly where fuel-powered pumps or generators are run indoors — a real risk once equipment arrives in a basement.
Insurance changes who does the work
Worth knowing before you call anybody. On an insured loss your insurer will often direct you to a vendor from their own panel. That is their prerogative and it is sometimes the fastest route, so speak to your broker early — before drying equipment is running, not after.
Choosing your own contractor matters most on everything else: losses under your deductible, damage that is not covered, buildings where you would rather not use the adjuster's vendor, and the many smaller events nobody claims for at all. In practice those are most of them.
What to write down, and why it is nearly always the times
Everything after a water event is judged on timing, and timing is the one thing nobody records while it is happening, because everybody is busy carrying things out of a room.
Four times:
- When it was discovered
- When the source was stopped
- When drying actually started — equipment running, not equipment booked
- When each area was confirmed dry
Four facts: the area affected, the type of water, the materials involved, and who did what.
If the start is genuinely unknown, say so and bracket it. "Discovered 08:10 Monday, last known dry 17:00 Friday" is a defensible entry that an adjuster can work with. A guessed start time that later turns out to be wrong is considerably worse than an honest range.
We publish a free printable water damage incident log built around exactly those four times. It is free, there is no account, and you can print it or save it as a PDF.
Asbestos, once materials start coming out
Restoration means cutting things out. In a building of any age, drywall, ceiling tiles, insulation, flooring and their adhesives can contain asbestos — and unlike mould, asbestos is genuinely regulated in Ontario: work is classified Type 1, 2 or 3 by hazard, training is mandatory, and there are notification and procedural requirements before certain projects begin. A competent contractor raises it before demolition starts. If it never comes up in the conversation, raise it yourself.
What cleaning contributes
- The clean after restoration. Once the contractor has dried the space and released it, the building has to go back into service — residual dust and debris on every surface and ledge, floors, carpets, washrooms, corridors, common areas. Ordinary commercial cleaning, and the arrangement already described on our property management cleaning page.
- The ordinary end on the day. A spill, an overflowing washroom, standing water from a burst pipe in a small area — cleaned properly and dried rather than left damp.
- The routine that stops the small ones. Surfaces dried rather than left wet, carpets extracted and properly dried rather than over-wetted, drains and condensate trays kept clear.
Frequently asked questions
How quickly does water damage need to be dealt with?
Faster than most people expect, and there is a published figure. The Canadian Centre for Occupational Health and Safety advises cleaning up floods and spills immediately, within 24 to 48 hours, and states that rapid drying is what prevents mould growth. Past roughly that window you stop having a water problem alone and start having a mould problem as well, which means a second contractor and a second bill. The practical consequence is that the useful question on discovering water is not how bad it looks, but how long it has been wet.
What gets dried out and what has to be thrown away?
Hard, non-porous surfaces such as sealed concrete, tile, metal and glass can generally be cleaned, dried and kept. Porous materials that have been wet for 48 hours or more generally cannot: CCOHS is direct that flooring soaked by flood water should be removed and discarded, and the same reasoning applies to soaked drywall, insulation, ceiling tiles and carpet underlay, because materials that hold water inside themselves do not reliably dry. Anything touched by contaminated water is treated the same way regardless of how long it has been wet. A proposal to dry everything in place several days after the event deserves hard questions.
Is flood water dangerous?
Assume so until somebody qualified establishes otherwise. CCOHS advises always assuming flood water is contaminated with sewage and chemicals, and puts minimum respiratory protection for flood cleanup at an N95 or better. In practice there are three situations: clean supply water from a burst pipe or sprinkler head, water that has picked up contamination on its way through a ceiling or across a floor or out of an appliance, and sewage or drain backup, which is a different job entirely and not somewhere to put ordinary staff. CCOHS also warns about carbon monoxide building up where fuel-powered pumps or generators are run indoors.
Does insurance decide who does the work?
Frequently, yes. On an insured loss the insurer will often direct you to a vendor from their own panel, which is their prerogative and is sometimes the fastest route, so speak to your broker early rather than after drying equipment is already running. An independent contractor of your own choosing matters most on everything else: losses under your deductible, damage that is not covered, buildings where you would rather not use the adjuster's vendor, and the many smaller events nobody claims for at all.
What should a restoration quote contain?
How soon equipment can be on site, given the 48-hour window. How the contractor will decide what is saved and what is removed, which should mean moisture readings rather than opinions. Where the water is coming from and who is fixing that, because drying a space while the source still runs is wasted money. What monitoring you receive, meaning daily readings and a written record of when each area was confirmed dry. Whether asbestos has been considered if materials are being cut out of an older building. And what happens if more damage is found behind a wall. All of it in writing before anyone starts.
Could asbestos be involved?
In a building of any age, yes, and it changes the sequence. Restoration means cutting out materials, and drywall, ceiling tiles, insulation, flooring and their adhesives can contain asbestos. Unlike mould, asbestos is genuinely regulated in Ontario: work is classified Type 1, 2 or 3 according to the hazard, training is mandatory, and there are notification and procedural requirements before certain projects start. A competent contractor raises this before demolition begins. If it never comes up, ask.
What should a property manager write down?
Four times and four facts. The times are when it was discovered, when the source was stopped, when drying actually started, and when each area was confirmed dry. The facts are the area affected, the type of water, the materials involved, and who did what. Timing is what everything afterwards turns on and it is the one thing nobody records while it is happening, because everybody is busy carrying things out of a room. If the start is genuinely unknown, write that down honestly and bracket it: discovered Monday morning, last known dry Friday evening is a defensible entry, and a guessed start time that turns out to be wrong is worse.
We only had a small leak. Does any of this apply?
The clock does, and that is the part that catches people. A small volume of water sitting in an enclosed space, under a floor covering or inside a wall cavity behaves the same way as a large volume: it stays wet, and past roughly 48 hours it grows something. The difference between a small leak and an expensive one is almost never the amount of water, it is how long nobody dealt with it. A roof leak that has been quietly wetting insulation for a month is a worse problem than a dramatic burst pipe found the same morning.
This article is general information for people running commercial buildings in Ontario. It is not legal, insurance or technical advice, and it is not an assessment of any specific building or claim. Zusashi Maintenance does not perform water damage restoration, moisture testing or clearance. The 24 to 48 hour figure, the guidance on discarding soaked materials, the advice to assume flood water is contaminated, and the protective-equipment and carbon monoxide points are drawn from the Canadian Centre for Occupational Health and Safety's published guidance on flood cleanup and on mould in the workplace; the asbestos requirements are Ontario Ministry of Labour material. Verify against the sources before relying on them.