Keeping A Flat Roof
A flat roof that is inspected twice a year lasts years longer than the same roof inspected when it leaks, and the difference is not a small one.
Short answer
Two inspections a year — spring and fall — plus drain clearing before winter and after leaf fall, is the program. The spring visit finds what the winter did; the fall visit gets the roof ready for it. Everything else is dealing with what those two find.
The spring inspection
Seams and laps, which freeze-thaw cycling will have worked at.
Parapet cap flashing and the wall base flashing, which is where the ice sat.
Blisters and splits in the membrane, which open over winter.
Drains and scuppers, for damage as well as blockage.
Ponding areas, which show as a tide line and which indicate a slope problem.
And mechanical curbs and penetrations, where the winter movement shows.
The fall visit is the important one
Clearing the drains and the scuppers before winter is the single highest-value maintenance task on a Toronto flat roof. A blocked drain turns a snowfall into standing water and then into ice, and that is how a roof that was fine in November becomes a claim in February.
The fall inspection
Clear every drain, strainer and scupper, after leaf fall rather than before it.
Clear debris from the whole field, particularly against parapets and curbs where it collects.
Repair any open seam or split before the first freeze.
Check and reseal penetrations and pitch pockets.
Check that mechanical units are properly supported off the membrane and that condensate lines are clear and discharging where they should.
And make sure roof access and any safety provision is sound, because winter access matters.
What to keep as records
A dated report with photographs from each visit, so change over time is visible.
A roof plan with the drains, penetrations and repairs marked, which makes the next visit faster and the next leak easier to find.
A log of every repair with its location and date.
The membrane type, the install date and the warranty terms, because warranty claims need them and nobody can ever find them.
Moisture survey results if one has been done, which establishes whether the insulation is wet and therefore whether patching is worth anything.
And a budget line and a projected replacement year, so the replacement is planned rather than forced by a February leak.
Common questions
How often should a flat roof be inspected?
Twice a year, spring and fall, with the drains cleared before winter.
What is the highest-value task?
Clearing the drains and scuppers after leaf fall and before the first freeze.
Why keep a roof plan?
It makes inspections faster and the next leak much easier to trace.