Why a shingle can't go there
Shingles shed water; they don't hold it back. Below roughly a 2:12 pitch there isn't enough slope to move water off the roof before it finds a seam, so a shingled low-slope section is a leak with a schedule attached. Rear additions, sunrooms, garages, porch roofs and dormer tops are the usual suspects around Wellington County, and they're often the part of the house that was added later by someone who didn't want to change materials.
Fall, drains and a continuous membrane
A flat roof isn't actually flat — it's built with a deliberate fall toward the drains or scuppers, and the membrane is a continuous sealed surface rather than overlapping pieces. That difference is the whole point: the roof stays watertight even when water sits on it for a day after a storm.
The systems we install
TPO
A single-ply sheet, hot-air welded at the seams so the joins are effectively part of the same membrane. It's light, it's usually white or light grey so it reflects a lot of summer heat off the room below, and it's clean to install — no torch, no kettle. It has become the default for residential additions and garages, and it's what we recommend most often for a straightforward rectangular section.
Torch-down and modified bitumen
Two plies of asphalt-based membrane, the cap sheet torched to the base so the whole assembly fuses. It's tough, it takes foot traffic well, and it's very forgiving around awkward geometry — parapets, tight corners, odd penetrations and roofs that have been patched by three different people. Where a roof has a lot of detail rather than a lot of area, this is often the better answer.
Which one suits your roof depends on the deck, the drainage, how much sun it takes and what's already there. We'll tell you which we'd use and why when we quote it, rather than fitting your roof to whatever we happen to prefer.
Skylights
Flashing kits, not sealant
Skylights get blamed for a lot of leaks that are really flashing failures. The unit itself is usually fine; what fails is the kit around it, or the fact that there was never a proper kit — just sealant packed around a hole. When we install or replace a skylight we use the manufacturer's flashing kit for that model and that roof pitch, integrated into the underlayment so water is directed back onto the roof surface rather than dammed behind the frame.
Replacing a skylight during a re-roof
If you're already re-roofing, that's the moment to deal with a skylight. Replacing a twenty-year-old unit while the deck is open costs a fraction of doing it as its own job later, and it means the flashing and the roof are the same age. We handle the install on the same visit rather than sending you to a second trade.
Ponding, drains and the things that go wrong
Standing water is the clearest warning sign on a flat roof. A little after heavy rain is normal; water still sitting there two days later means the fall is wrong, the drain is blocked, or the deck has sagged. We check drainage before quoting, because laying a new membrane over a drainage problem just buys you a few years and the same phone call. Blistering, open seams, cracked flashing at the parapet and soft spots underfoot are the other things we look for when we're tracing a leak.
Booking it
Membrane work is weather-dependent — it wants a dry deck and reasonable temperatures, so spring through fall fills up quickly. If you've got a leak over an addition, call as soon as you notice it rather than waiting for the season to turn. Quotes are free, written, and given after we've been up on the roof: (519) 400-3840.
Common questions
Why can't shingles go on a flat or low-slope roof?
Shingles shed water; they don't hold it back. Below roughly a 2:12 pitch there isn't enough slope to move water off the roof before it finds a seam, so a shingled low-slope section is a leak with a schedule attached. Rear additions, sunrooms, garages, porch roofs and dormer tops are the usual suspects around Wellington County.
Should I use TPO or torch-down on my flat roof?
TPO is a single-ply sheet, hot-air welded at the seams, light and usually white or light grey so it reflects summer heat off the room below. It's what we recommend most often for a straightforward rectangular section. Torch-down modified bitumen is two plies fused together: tough, good with foot traffic, and very forgiving around parapets, tight corners and odd penetrations. Where a roof has a lot of detail rather than a lot of area, torch-down is often the better answer.
Is standing water on a flat roof normal?
A little after heavy rain is normal. Water still sitting there two days later means the fall is wrong, the drain is blocked, or the deck has sagged. We check drainage before quoting, because laying a new membrane over a drainage problem just buys you a few years and the same phone call.
Do skylights always leak?
Skylights get blamed for a lot of leaks that are really flashing failures. The unit itself is usually fine; what fails is the kit around it, or the fact that there was never a proper kit — just sealant packed around a hole. We use the manufacturer's flashing kit for that model and that roof pitch, integrated into the underlayment so water is directed back onto the roof surface.
