📞 (647) 494-1699Get a Free Quote
Free Quote
Flat Roofing

Modified Bitumen (Torch-On) Roofing in Toronto & the GTA

Walk the laneways of any older Toronto neighbourhood and most of the flat roofs you see are torch on roofing — two ply modified bitumen, the granulated cap sheet in grey or white. There's a reason the city's roofers keep coming back to it: SBS-modified bitumen stays flexible through freeze-thaw, takes foot traffic without complaint, and its details at walls, chimneys and skylight curbs are built up by hand rather than hoped into place.

A proper mod bit roof is two layers — a base sheet and a torch down cap — so a scuff or granule loss in the cap still leaves a waterproof ply underneath. The open flame is the serious part. Torching near wood-frame walls and old dry sheathing demands trained hands, heat awareness at every hidden cavity, and a fire watch after the torches go quiet. This is not a trade for the lowest bidder with a rented torch.

We quote two ply roofing itemized: tear-off, deck allowance, insulation, base, cap and metal. Where open flame is a bad idea — over exposed rafters, against certain claddings — we'll quote self-adhered SBS membranes that give the same two-ply build without the torch. And if your existing torch-on just has one tired flashing, we'll quote the repair, because a sound mod bit roof is worth keeping.

What this covers

  • Tear-off of existing roofing and inspection of the deck beneath
  • Replacement of rotted sheathing and re-securing of loose boards
  • Insulation or overlay board above the deck, tapered to drains where slope is short
  • Two ply SBS system: mechanically fastened or adhered base sheet plus torch-applied cap sheet
  • Self-adhered base and cap options where open flame isn't appropriate
  • Hand-built flashing details at parapets, walls, chimneys, stacks and curbs
  • New metal drip edges, counter-flashings and eavestrough tie-ins
  • Fire watch during and after torch work, then full cleanup and disposal

What affects the price

  • Roof complexity — mod bit earns its keep on cut-up roofs, but every wall and curb is hand-detailed labour
  • Torch versus self-adhered application; self-adhered membranes cost more in material but remove the flame risk
  • Tear-off depth: layers of old roofing and any waterlogged insulation underneath
  • Deck condition, priced as a stated allowance rather than discovered on the invoice
  • Cap sheet colour and grade — white granules reflect more heat and cost a little more
  • Insulation added above the deck and the flashing height changes that come with it
  • Access for bins, propane and material hoisting

Every home is different, so we don’t publish flat prices — the quote is free and based on your actual job.

Modified Bitumen (Torch-On) Roofing near you

We take quote requests across the GTA. Local pages:

TorontoEtobicokeNorth YorkScarboroughEast YorkYorkMississaugaBramptonCaledonVaughanMarkhamRichmond HillAuroraNewmarketKingWhitchurch-StouffvilleEast GwillimburyGeorginaPickeringAjaxWhitbyOshawaClaringtonUxbridgeOakvilleBurlingtonMiltonHalton HillsHamiltonSt. CatharinesNiagara FallsGrimsbyNiagara-on-the-LakeBarrieInnisfilBradford West GwillimburyNew TecumsethKitchenerWaterlooCambridgeGuelphOrangeville

Common questions

Is torch-on roofing safe on a house?
In trained hands, yes — it's been the standard flat roof on Toronto homes for decades. The genuine risks are torching against combustible walls, into hidden cavities, and leaving site too soon after the flame is out; smouldering can take hours to show. Ask any bidder how they handle fire watch. Where flame is a bad fit, self-adhered SBS gives the same roof without it.
How long does a two ply modified bitumen roof last?
A well-installed SBS two ply system typically serves 20 to 30 years in the GTA — the two-layer build gives it margin that single ply roofs don't have. Cap sheet granule loss late in life doesn't mean immediate failure; it means the roof is entering its last stretch and coating or replacement should be planned rather than forced by a leak.
What's the difference between torch down and self-adhered membrane?
Same SBS material, different attachment. Torch down is heat-fused, giving a strong monolithic bond, but it puts open flame on your roof. Self-adhered (peel-and-stick) versions bond with factory adhesive — no flame, cleaner around walls and cavities, and the right call on many wood-framed homes — at a somewhat higher material price. Performance is comparable when the details are done well.
Can I put new torch-on over my old flat roof?
Occasionally, and it's tempting because it skips tear-off. It's only legitimate over a single dry existing layer on a sound deck. Over wet insulation or a second old roof it just seals the problem in — the moisture blisters the new cap and rots the wood below. Most older Toronto roofs we open have moisture in them, so plan on tear-off and treat overlay as a pleasant surprise.
Why is mod bit recommended over rubber for my roof?
Usually because of the shape of your roof. Lots of walls, a chimney, skylights, regular foot traffic to a deck or AC unit — that's where two ply mod bit shines, since its details are built up in layers and the granulated cap resists wear. On a plain open rectangle with no traffic, EPDM rubber does the job with fewer seams and often less money.

Ready to sort out your modified bitumen (torch-on) roofing?

Tell us what your home needs — a small fix or a full project — and get a free quote.

Get a Free QuoteWhatsApp usCall (647) 494-1699