Torch-on roofing is a modified-bitumen membrane system in which heat is used to bond the torch-applied membrane during installation, including where sheets overlap. It is one of the systems used within the wider category of low-slope roofing, not another name for it.
GoodVans Roofing's torch-on service covers installation, repair and maintenance on commercial and industrial roofs in Metro Vancouver. This page is about torch-on specifically: what sets the system apart, where its condition changes, and how to tell a contained torch-on repair from a wider replacement.
What Makes Torch-On Different
Modified-bitumen membrane: the roofing is made of sheets of modified bitumen rather than a single-ply membrane or metal.
Heat-applied bond: heat forms the bond in the torch-applied membrane.
Bonded overlaps: adjoining sheets overlap and are bonded to each other, so the roof relies on those joins being continuous.
Prepared substrate: surface preparation affects how the membrane bonds, and the required preparation depends on the existing roof assembly.
Detailed terminations: wherever the membrane stops or turns, it has to be finished so it stays part of the same covering.
Installation is professional work carried out with heat. The quality of a torch-on roof depends on the preparation, the bond and how every overlap and termination is formed, which is why the whole system, not only its surface appearance, is considered.
What Lies Beneath the Membrane
The membrane surface is only part of the picture. What the torch-on roof is bonded to, and whether there are earlier layers beneath it, can affect whether a repair will hold and how much a replacement involves. Some of it is out of sight until part of the roof is taken up. That does not mean a problem is expected underneath; it means the scope should allow for what may be found.
Laps, Seams and Details
A torch-on roof is judged at its joins as much as at its sheets. Across the open roof area, the membrane forms the main covering. At laps between sheets, and where the membrane meets a vent, pipe, curb, rooftop equipment, parapet, wall, roof edge or change of level, continuity depends on how those details are formed.
That is why an assessment of a torch-on roof pays attention to where sheets join and where the membrane ends, not only to the broad areas in between. A lap that has started to open, or a termination that has pulled away, can matter more than its size suggests.
Signs on a Torch-On Roof
These can indicate that a torch-on roof may warrant assessment: a lap edge that has lifted, so the overlap is no longer bonded down; cracking or splitting across the membrane surface; punctures or gouges from dropped tools, equipment work or traffic; blisters or bubbles, which can indicate a condition within or beneath the membrane that needs assessment; areas where the surface looks worn or eroded; terminations pulling away at walls, parapets, curbs or edges; and damage near equipment or where other trades have been working.
None of these establishes the full scope on its own. The same sign can come from a single detail or from wider change across the roof, and the difference decides what work makes sense.
- Lifted laps
- Cracks & splits
- Punctures & blisters
- Loose terminations
Repairing Torch-On or Replacing More
GoodVans Roofing carries out torch-on repairs as well as new installations.
A torch-on repair may fit when one lap has come unbonded; a patch of membrane is damaged and the membrane around it is serviceable; the detail around one penetration or edge needs work; or the problem can be isolated and addressed locally.
Wider replacement may need consideration when laps are coming unbonded in many places; the membrane has deteriorated over large areas; many details are affected at once; or local work would not give a sensible, contained scope.
These are indications, not rules. Neither the roof's age nor any single sign settles the decision on its own.
When Torch-On Is Not the Main Question
You are still choosing between torch-on and other low-slope systems: Low-Slope Roof Systems
A coating over the existing torch-on membrane is being considered: Roof Coatings & Waterproofing
The torch-on roof needs a record and a schedule rather than a one-off repair: Roof Asset Management Plans
The main constraint is the warehouse operation below the roof: Warehouse Roofing
The main constraint is the production or equipment below the roof: Factory & Plant Roofing
The main constraint is guests staying in the building: Hotel Roofs & Maintenance
The Commercial & Industrial Roofing page lists every commercial service.
When a Torch-On Roof Is Replaced
Replacing a torch-on roof raises questions specific to the existing assembly: what torch-on assembly is on the roof now, and how many layers are present; which parts of the existing roofing come off, as established by assessment; what the exposed surface reveals after removal; whether torch-on remains the right system, or another low-slope system suits the building better; and how each termination and penetration is tied into the new torch-on membrane.
Seam checks and a leak test are part of how GoodVans Roofing finishes a torch-on project.
Where GoodVans Provides Torch-On Roofing
Torch-on roofing from GoodVans Roofing is available for commercial buildings throughout Metro Vancouver, as well as selected Fraser Valley communities.
Commercial Torch-On FAQs
Can a torch-on roof be repaired?
Yes, where the problem is contained and the membrane around it is still serviceable. Repairs can address an opened lap, a damaged section of membrane or a failing detail. Where similar problems appear across the roof, a wider scope may be the better course.
Why do laps and seams matter on a torch-on roof?
Because the roof only works as a continuous covering if the overlaps between sheets stay bonded. The sheets themselves are one material; the laps and terminations are where continuity depends on how the work was done, so they are among the first places an assessment looks.
Is torch-on used on houses as well as commercial buildings?
Yes. Torch-on is also used on flat sections of houses, which GoodVans Roofing covers through its residential services. This page deals with torch-on on commercial and industrial buildings.
Does a torch-on roof need maintenance?
Yes. Torch-on is not maintenance-free: keeping drains clear, checking laps and details, and looking over the roof after other trades have worked on it all help. How often depends on the roof and how it is used, and scheduled oversight is available through Roof Asset Management Plans.
Not sure whether to repair or replace?
An assessment looks at the laps, terminations and membrane together before a torch-on scope is set.
