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American Standard Coatings ASC APP 4.5 Granulated Heat-Welded Cap Sheet
Regular price $80.30Orders start at $399 — combine any items to reach the minimum. Learn more
ASC APP 4.5 Granulated Heat-Welded Modified Bitumen Cap Sheet, 1 Square Roll, Polyester Reinforced
This is the ASC APP 4.5 G, a polyester-reinforced APP modified bitumen granulated cap sheet roll designed for heat-welded multi-ply roofing. Each roll covers 1 square (32.25 ft long x 39.625 in wide) and weighs about 110 lbs. It is used as the cap sheet or flashing membrane in APP systems over new construction and reroofing.
Key Features:
- Heat-weld application: Bottom surface has a factory-applied burn-off film made for torch heat-welding.
- Polyester reinforcement: High-performance stress-resistant polyester mat provides flexibility, dimensional stability and excellent tear and puncture resistance.
- Cap sheet or flashing: Designed as the mineral-surfaced cap sheet in APP multi-ply systems and usable for wall, base and field flashings.
- Granule surfacing: Granulated top surface with 2 g granule embedment for UV and weather protection.
- New or reroof: Suitable over various substrates for both new construction and reroofing on most low-slope roof decks.
- Tear and puncture: Tear strength of 70 lbf and peak load of 50 lbf/in. per ASTM D5147.
Specifications Table:
| Specification | Details |
|---|---|
| Brand | ASC |
| Manufacturer model | ASCAPP45G |
| Sell unit | 1 roll, 1 square |
| Product type | APP modified bitumen granulated cap sheet / flashing sheet |
| Chemistry / base | Atactic Polypropylene (APP) modified bitumen, polyester reinforced |
| Color | Black (also Burnt Sienna, Slate, Weatherwood, White) |
| Roll size / coverage | 1 square per roll; 32.25 ft long x 39.625 in wide |
| Thickness | 4.5 (nominal, per product designation) |
| Length | 32.25 ft |
| Width | 39.625 in |
| Coverage per unit | 1 square (100 sq ft) per roll |
| Application method | Heat-weld (torch applied); do not use cold adhesives or hot asphalt |
| Reinforcement | High-performance stress-resistant polyester mat |
| Peak load (ASTM D5147) | Min 50 lbf/in. (8.8 kN/m) at 73°F |
| Elongation | 23% at peak load at 73°F |
| Tensile strength / tear | Tear strength 70 lbf (311 N) at 73°F |
| Low temperature flexibility | 32°F (0°C) max |
| Granule embedment | 2 g |
| Weight | Approx. 110 lbs per roll |
| Pack quantity | 1 roll per pack; 24 rolls per pallet |
| Manufacturer warranty summary | Limited (product only) and NDL (product and workmanship) warranties available depending on roof system configuration and contractor selection; one-year manufacturing defect warranty |
Coverage & How Much You Need:
Each roll covers 1 square (100 sq ft nominal) at 32.25 ft long by 39.625 in wide. Size your job by roll count with laps included: install over base ply lapped per the ASC specifications with a minimum 6 in. offset between base ply and cap sheet laps, and verify a minimum 3/8 in. flow of modified compound at side and end laps.
Fit and Compatibility:
ASC APP 4.5 G installs over one ply of ASC APP 2.0 Torch Base Sheet (sold separately), mechanically fastened to nailable substrates or mopped in hot asphalt to non-nailable or insulated substrates. It is torch-applied only; cold adhesives and hot asphalt are not permitted with this membrane, and it must not be applied over shingles or other granulated surfaces.
Frequently Asked Questions (FAQ):
Q: What is included in the order?
A: One roll of ASC APP 4.5 Granulated heat-welded cap sheet, covering 1 square (100 sq ft nominal).
Q: What size is each roll?
A: Each roll is 32.25 ft long by 39.625 in wide and weighs approximately 110 lbs; rolls ship 24 per pallet.
Q: How is it installed?
A: It is heat-welded with a torch over the ASC APP 2.0 Torch Base Sheet, lapping 2 in. on sides and 4 in. on ends with a minimum 3/8 in. flow of modified compound at laps.
Q: What substrates can it go over?
A: Various substrates on most low-slope roof decks for new construction or reroofing, including wall treatments, base flashings and field flashings; never over shingles or granulated surfaces.
Q: Can it be adhered with cold adhesive or hot asphalt?
A: No, this membrane is designed for heat-weld application only.
Q: Is there a warranty?
A: ASC Building Materials offers limited (product only) and No Dollar Limit (product and workmanship) warranties; type and duration depend on roof system configuration and contractor selection.
Expert Verdict — Reviewed by the SuperArbor Pro Desk
Choose APP 4.5 G when you need a durable torch-applied cap sheet for a low-slope multi-ply system or flashing detail. Ensure the base ply is set with proper side/end lap offsets and positive drainage before torching, and stagger the cap sheet laps at least 3 ft apart over the base. In cold weather, handle rolls carefully to avoid cracking and check that the assembly's fire rating is appropriate for combustible substrates.
Torch application is a fire hazard: only properly trained roofing professionals should install this product, keep an ABC-approved fire extinguisher at each torch, and maintain a fire watch for at least 60 minutes after the last heat-welded work of the day.
Order the ASC APP 4.5 Granulated heat-welded cap sheet roll for your next multi-ply low-slope roofing job.
Product Documents:
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