GAF Ruberoid White Granule Torch Membrane: Lightweight Modified Bitumen That Delivers

GAF’s torch membrane solves the weight problem that traditional built-up roofing can’t touch. At less than 2 pounds per square foot for standard applications, this APP-modified membrane cuts structural load by more than half compared to hot-mopped systems while delivering the durability contractors expect from modified bitumen.

The polyester mat core resists splits and tears better than fiberglass-reinforced alternatives. APP polymer modification provides the weather resistance. White granule surfacing reflects heat and UV. The whole system installs with a torch — no kettles, no adhesives, no mess.

Weight Specs and Installation Advantages

The lightweight design (under 2-3 psf) reduces structural load compared to BUR, which matters when you’re already calculating for Montana snow loads. Standard rolls weigh approximately 104 pounds and cover one square plus change.

Specification	Value
Coverage	1 Square (100 sq. ft.)
Installed Weight (Standard)	< 2 lbs per square foot
Installed Weight (Premium)	< 3 lbs per square foot
Roll Weight	Approx. 104 lbs
Roll Dimensions	32’ 6” × 39.5”
Thickness	175 mil (4.4 mm) nominal
Core Material	Non-woven polyester mat
Coating	APP polymer-modified asphalt

No hot asphalt or adhesive required — that’s the real advantage here. Torch application means faster installation and no equipment rental for kettles or adhesive sprayers. Typically 3” side laps and 6” end laps give you standard overlap without wasting material.

The membrane works over concrete, approved insulation boards, existing BUR systems — versatility that matters when you’re dealing with retrofit work. GAF Matrix™ primers and roof cements recommended for optimal adhesion, though any compatible primer should work.

Fire and Wind Performance That Meets Code

Fire retardant versions carry Class A rating. The FR and EnergyCap versions meet UL Class A Fire Rating and FMRC Class A Fire Rating requirements. For commercial work, that’s not negotiable.

Wind resistance testing shows FMRC Class 1-180 Wind Uplift resistance (over concrete decks). In Montana’s chinook belt around Great Falls where winds regularly hit 40+ mph with higher gusts, that rating provides confidence. The ASTM D6222 Type II compliance covers you for code requirements.

ICC ESR-1274 listing means the product has been evaluated for code compliance — one less thing to argue about during inspection.

Cool Roof Performance and Energy Specs

The white granule surface isn’t just cosmetic. Initial SRI of 89 puts this membrane well into cool roof territory. Emissivity of 0.91 means it releases absorbed heat effectively. Cool Roof Rating Council (CRRC) listed (EnergyCap version) provides third-party verification for energy rebate programs.

White granule surface provides UV protection and reduces energy costs (EnergyCap version). In summer heat, that reflectivity translates to lower cooling loads for the building below. The granules also protect the APP polymer from UV degradation — extending membrane life compared to smooth-surfaced alternatives.

Frequently Asked Questions

What’s the actual coverage per roll? Standard coverage is 1 Square (100 sq. ft.), though some rolls provide slightly more — 106.9 sq. ft. (approx. 1.07 SQ) for the Torch Plus Granule FR variant.

How does this compare to TPO for commercial roofing? Modified bitumen often provides better redundancy/durability than basic single-ply TPO at a competitive price. The multi-layer construction of modified bitumen gives you backup protection if the top layer gets damaged.

What warranty coverage is available? Typical system guarantees up to 15 years. Select system constructions available with up to 20-year coverage. Guarantees are subject to GAF’s specific warranty terms and professional installation.

Can this go directly over existing roofing? Yes, it’s compatible with existing built-up roofing (BUR) or modified bitumen systems. Always verify the existing roof can handle the additional weight and that local codes allow recover systems.

What accessories are needed for installation? Accessories (sold separately): Torches, LPG tanks, Primers, Trowels, Seam tools. The membrane itself is one 100-107 sq. ft. roll of membrane per package.