What We Do

Flat Roofing in London, Ontario

Membrane roofs for additions, garages and low-slope buildings, drained properly.

Book an Inspection Call +1 (519) 555-0100

Built for London

Flat Roofing in London, Ontario: Drainage Is the Whole Job

London's older neighbourhoods are full of flat and low-slope roofs: rear additions on Old South homes, detached garages in Old East Village, porch roofs and small shops along Dundas and Hamilton Road.

Most of them fail the same way. Water pools, the membrane blisters, and the seams open. A proper replacement fixes the slope with tapered insulation, places the drains where the water actually goes, and welds every seam.

Modified bitumen suits small detailed roofs; single-ply TPO suits bigger simple ones. The scope lists which and why, with the price, before any work starts.

Why Choose Us

Why London Homeowners Choose Us for Flat Roofing

Drainage Designed In

Tapered insulation and drains placed so water leaves instead of pooling.

Torch-On or Single-Ply

Modified bitumen or TPO chosen for the roof size, use and budget.

Seams That Hold

Heat-welded seams, not glued laps, at every joint and flashing.

Written Scope First

Membrane type, insulation, drains and edge metal listed and priced before you book.

Materials & Specs

What We Use for Flat Roofing

Industry-standard materials and specifications you can rely on.

Membrane Options

Two-ply modified bitumen (torch-on) or single-ply TPO/PVC, based on roof

Insulation

Polyiso with tapered sections to drains, typically 1/4 inch per foot slope

Seams

Heat-welded or torch-fused laps, industry typical

Service Life

20 to 30 years with proper drainage, industry typical

Installed Cost

Roughly $8 to $15 per sq ft in Ontario, 2026 market range

How It Works

Your Roof, Done in 4 Steps

From the first call to the final walkthrough, here is what happens and when.

Flat Roof Assessment

The roof is walked for ponding, blisters and soft spots, the drains checked, and the deck probed before a written scope is prepared.

Tear-Off and Deck Repair

Old membrane and wet insulation removed, deck repaired, then new insulation set with tapered pieces toward the drains.

Membrane Installation

Base and cap sheets torched down, or single-ply membrane rolled and heat-welded at every seam, then flashed at walls and drains.

Edge Metal and Water Test

Drip edge and wall flashings fitted, drains cleared, the roof flooded or hose-tested to confirm it drains, then walked through with you.

Water testing a completed flat roof in London, Ontario

Where It Works

Ideal Applications for Flat Roofing

Rear Additions

Low-slope kitchen and family-room additions on older London homes.

Detached Garages

Flat-roofed laneway and backyard garages common in the city's pre-war neighbourhoods.

Porch and Carport Roofs

Small membrane roofs over front porches, side entries and carports.

Small Commercial

Single-storey shops, offices and plazas around London and St. Thomas.

Rooftop Decks

Membrane roofs under walkable deck surfaces on urban additions.

Common Questions

Flat Roofing — Frequently Asked Questions

How much does a flat roof cost in London, Ontario?

Published Ontario ranges for modified bitumen and single-ply flat roofs typically run $8 to $15 per square foot installed, with insulation, drain work and tear-off moving the number. A written quote after an inspection is the reliable figure for your roof.

How long does a flat roof last?

A two-ply modified bitumen roof typically lasts 20 to 25 years, and single-ply TPO or PVC membranes 20 to 30 years, when drainage is right. Standing water is what shortens a flat roof's life.

Why does my flat roof pool water?

Usually because the deck has settled or the roof was built without slope toward the drain. It is fixed with tapered insulation or added drains during a replacement, and the inspection will show where the low spots are.

Can you do a flat roof on a garage or porch?

Yes. Detached garages, porch roofs, rear additions and carports are the most common flat roofs in London's older neighbourhoods, and a small membrane roof is often a one-day job.

What is the difference between torch-on and TPO?

Torch-on (modified bitumen) is an asphalt-based two-layer system heat-applied with a torch; TPO is a single white plastic membrane with heat-welded seams. Torch-on suits small residential roofs with many details; TPO suits larger, simpler roofs and reflects more heat.

See all FAQs →

Where We Work

Serving London & Middlesex County

Based in London and working within about 40 km, from St. Thomas and Strathroy to Woodstock, Ingersoll and Lucan.

London St. Thomas Strathroy Woodstock Ingersoll Dorchester Komoka Ilderton Lucan

Get a Flat Roofing Quote

Tell us about your project — we’ll call you back within one business day.

We’ve got your request!

We’ll call you back within one business day. Need us sooner? Call +1 (519) 555-0100.

Not Sure If It's a Repair or a Replacement?

Book an inspection. A roofer walks the roof and attic, shows you the photos, and puts the scope and price in writing. No obligation either way.

Book an Inspection