Torch Roofing

Heat-welded thermal seal for low-slope roofs — a monolithic, waterproof envelope.

Heat-welded thermal seal for low-slope roofs.

Two-ply SBS-modified bitumen system torch-applied for a monolithic, waterproof envelope. The propane torch melts the underside asphalt, chemically fusing the membrane to the substrate — no seams, no gaps.

Membrane
SBS 180 g/m² polyester
Thickness
4 mm cap sheet
Service life
20 – 25 years
Slope
1/4:12 minimum
REF · 05DWG-R01
The Smart Homeowner’s Guide toTorch-Down Flat RoofingCap Sheet (Mineral)Heat-Fused SeamBase Sheet SBSPolyiso Insulation R-25Plywood Roof DeckPropane TorchPropane TankParapet FlashingWooden JoistsBRAYNER CONSTRUCTION
Technical Comparison

Torch Roofing vs. Standard Roofing

The propane torch melts the underside of the SBS-modified bitumen membrane, chemically bonding it to the substrate. The result is a single, continuous waterproof envelope — no overlaps, no sealants, no failure points.

Specification
SYS-01
Torch-Down
SYS-02
Standard Asphalt
Sealing methodHeat-fused monolithic bondMechanical fasteners + adhesive
Seam integrityChemically welded, no cold jointsOverlapped, sealant-dependent
Slope requirement1/4:12 minimum (near-flat)4:12 minimum
Service life20 – 25 years15 – 20 years
UV resistanceMineral granule cap sheetAsphalt granules
Water penetration0 mm — seams disappearRisk at every overlap
Ideal useFlat commercial, garage, additionsSloped residential roofs
Zero cold joints
Waterproof over ponding
Faster crew install
Handles thermal expansion
Reference · Low-Slope Roofing

Where torch-down actually goes

Reference photos of two-ply SBS modified-bitumen roofs — commercial rooftops with HVAC, parapet-to-membrane detailing, and low-slope residential garages.