When a commercial roof fails, protect people and property inside first, contain the water, isolate electrical risk, then call a commercial roofing crew with a clear description of where and when it leaks. Keep everyone off the roof during the storm. Temporary containment stops interior damage; the permanent scope follows once the assembly can be opened and dried.
What counts as a roofing emergency?
Not every leak needs a crew that night, and treating every drip as an emergency exhausts a maintenance budget quickly. On a commercial or industrial building, the situations that justify immediate attendance are:
- Water reaching electrical panels, lighting circuits, elevator equipment or a server room.
- Active water over stock, production equipment, food handling areas or tenant premises where trade will stop.
- A visible opening in the roof: membrane lifted or peeled by wind, a fallen tree limb, storm debris impact, or a failed skylight or hatch.
- A ceiling that is bulging, sagging or holding water, which is a life-safety concern before it is a roofing one.
- Any sign of deck movement or structural distress, particularly under heavy snow load.
Everything else is urgent but schedulable: a slow stain that grows during rain, a drip in a storage area, a damp patch that appears only during a thaw. Sorting calls into those two tiers as they come in is the single most useful habit a property manager can build, because it keeps genuine emergencies from queueing behind routine ones.
What should happen in the first fifteen minutes?
Interior damage usually costs more than roof damage, and it accumulates while everyone is looking for a phone number. Work in this order:
- Move what can be moved. Stock, files, electronics and finished product out from under the leak. Cover what cannot be moved with poly sheeting.
- Contain the water where it is falling. Buckets overflow and spread the problem. Where the ceiling is already open, a drum with a hose run to a drain, or a bag taped to the penetration, controls where the water goes for hours rather than minutes.
- Isolate electrical risk. Have a qualified electrician de-energise affected circuits, fixtures and panels. Nobody should be standing in water near live equipment.
- Relieve a bulging ceiling deliberately. A trapped pocket of water in a suspended ceiling or drywall will let go on its own, unpredictably. Clear the area beneath it and have the pocket drained in a controlled way rather than waiting.
- Start the record. Time-stamped photographs and video of the water, the affected area and the weather conditions. Note the time the leak started and what the wind and rain were doing.
Then call. Our emergency roof repair team works on commercial and industrial buildings across the GTA, and the quality of the first phone call largely determines how fast the roof side moves.
What information should you have ready for the roofing crew?
A crew arriving with the right information reaches the entry point far sooner. Have these ready:
- Where it is coming in, inside. Unit or suite, grid reference or nearest column line, and what sits directly above on the roof if you know.
- When it leaks. Every rain, only in wind-driven rain from a particular direction, only during a thaw, or continuously since a specific storm. Each pattern points at a different cause.
- Deck and roof type, if it is on file, along with the age of the roof and the date of the last work done on it.
- Recent rooftop work. New mechanical units, conduit, antennae, solar equipment or anything a trade has installed in the last two years. Work by others is a very common source of new leaks.
- Roof access. Interior hatch, exterior ladder or lift required, who holds the key, and any restrictions on when the roof can be reached.
- Site constraints. Tenant hours, loading dock access, lane restrictions, hot work rules and whether an escort is required.
Keep a single page with this on it for every building you manage. It shortens the diagnostic phase of every call, and it is worth more at two in the morning than any other document in the file.
Why should nobody go on the roof during the storm?
Because a commercial roof in bad weather is genuinely dangerous, and the information gathered almost never justifies the exposure. Wet membrane and single-ply surfaces become extremely slippery. Snow hides skylights, hatches and roof openings that will not hold a person's weight. Wind at the perimeter of a tall building is stronger than at grade, and lifted membrane can move without warning. Standing water conceals trip hazards and open cuts in the assembly.
There is also a diagnostic reason. Water on the roof does not reveal where it is entering; if anything it hides it. The useful evidence in a live event is inside the building, and it is safe to collect. Send staff to the interior, not up the ladder.
What can a crew actually do during an active storm?
Expectations matter here. In an active weather event the objective is control, not a finished repair. Realistically that means:
- Assessing whether the roof can be accessed safely at all under current wind and surface conditions.
- Securing lifted or torn membrane so wind cannot peel more of the roof away, which is the difference between a repair and a much larger failure.
- Clearing blocked drains and scuppers so standing water can move, which relieves both the leak and the load.
- Applying a temporary measure at the identified opening: wet-applied patching, sheeting or mechanically secured cover, chosen for the conditions on the day.
- Documenting conditions and the work carried out for your insurance and maintenance file.
Permanent work needs a dry, workable assembly. Adhesives, membrane welding, insulation replacement and detailing all require conditions that a storm does not provide, and work forced through in the wrong conditions fails.
How does a temporary repair differ from a permanent one?
A temporary repair buys time. It stops water entering at the identified point so the interior can dry, trade can resume and the building can be secured. It does not address wet insulation, corroded fasteners, deck damage or the underlying cause, and it is not intended to.
The permanent scope comes after, usually in a scheduled visit with a proper weather window. It removes the wet material back to dry, replaces the insulation and cover board, rebuilds the failed detail and ties the new membrane into the surrounding field. Skipping this step is the most common reason a building sees the same leak again the following season, because the water still inside the assembly never left.
The other thing that gets missed after an emergency is the rest of the roof. A storm that opened one detail has usually stressed every similar detail on the building. A follow-up flat roof inspection once conditions allow catches the ones that have not started leaking yet. Where the assessment shows widespread saturation, the conversation moves to flat roof replacement rather than another round of repairs.
What belongs in the building's roofing file?
Property managers who handle roof emergencies well have prepared for them on a quiet day. A complete file holds:
- A roof plan marked with drains, scuppers, hatches, units, skylights and section boundaries.
- The roof assembly and deck type, the installation date and a log of every repair with dates, locations and photographs.
- The most recent condition report and moisture findings.
- Access details, keys, safety anchor points and any confined or restricted access notes.
- Your roofing contractor's contact details, plus the electrician, restoration contractor and insurance contact.
- Tenant contact list with after-hours numbers, and the notification order for an interior water event.
- A record of every trade that has worked on the roof, which is where new leaks often originate.
Distribute it to whoever answers the after-hours phone. A file that lives in one person's inbox is not a file. We work with managers on this kind of preparation through our property manager services.
How do you reduce the odds of the next emergency call?
Most emergency calls we attend were preventable, and the prevention is unglamorous. Drains and scuppers cleared before the autumn leaf fall and again before spring melt. Perimeter metal, curbs, pitch pockets and flashing checked twice a year. Snow managed before it drifts and loads unevenly at parapets and behind rooftop units. A rule that any trade going on the roof reports what they touched. Repairs scoped properly the first time instead of patched at the surface.
None of that eliminates storms. It does mean that when a storm arrives, the roof is starting from a known condition with clear drains rather than from a backlog. That is the whole argument for a flat roof maintenance programme on a commercial building, and it is why buildings with one call us far less often out of hours.
If you manage commercial or industrial property in the GTA and want your buildings prepared before the next event, get in touch with our team.