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Malarkey Right Start UDL Flexor SBS Polymer Modified Underlayment Roll - 2 Square Coverage
Regular price $95.33Orders start at $399 — combine any items to reach the minimum. Learn more
Malarkey Right Start UDL Flexor SBS Polymer Modified Underlayment Roll - 2 Square Coverage
Malarkey Right Start UDL Flexor is an SBS polymer modified fiberglass-reinforced underlayment supplied as a 2-square roll for steep-slope roofing. It installs as a primary underlayment beneath shingles and is approved for Class A assemblies under ASTM E108. One roll covers 2 squares and pairs with Malarkey shingle systems.
Key Features:
- SBS Modified: SBS polymer modified formulation delivers flexibility and tear resistance during installation.
- Fiberglass Reinforced: The abbreviated item description confirms a fiberglass (FIB) mat construction.
- Multi-Standard Listed: Meets ASTM D4601 Type II, D4869, D226 Type II and D6757 Type II.
- ICC-ES ESR-3150: Holds ICC-ES report ESR-3150 and FBC Approval #14809.
- Class A Rated: ASTM E108 Class A and ETL Listed for fire classification in approved assemblies.
- 10 Year Warranty: Backed by a Malarkey limited 10-year warranty.
- 2 Square Roll: Each roll covers 2 squares of roof area.
Specifications Table:
| Specification | Details |
|---|---|
| Brand | Malarkey |
| Sell unit | 1 roll, 2 squares coverage |
| Product line | Right Start UDL Flexor |
| Coverage per unit | 2 squares |
| Material | SBS polymer modified fiberglass-reinforced underlayment |
| Applicable standards | ASTM D4601 Type II; ASTM D4869; ASTM D226 Type II; ASTM D6757 Type II; ICC-ES ESR-3150; FBC Approval #14809; ASTM E108 Class A; ETL Listed |
| Manufacturer warranty summary | Limited Warranty (10 year) |
| Algae resistance | No |
| Weight | 75 lb gross per roll |
Coverage & How Much You Need:
Each roll covers 2 squares (200 sq ft) of roof area. Order rolls by dividing your roof square count by two and plan laps per the manufacturer's installation instructions.
Fit and Compatibility:
Designed as an underlayment beneath Malarkey asphalt shingle systems and other steep-slope shingle roofing. Shingles, fasteners and accessory flashings are sold separately.
Frequently Asked Questions (FAQ):
Q: How much does one roll cover?
A: One roll covers 2 squares, or about 200 square feet of roof deck before lap allowances.
Q: What standards does it meet?
A: It meets ASTM D4601 Type II, D4869, D226 Type II and D6757 Type II, plus ICC-ES ESR-3150, FBC Approval #14809, ASTM E108 Class A and ETL listing.
Q: Is there a warranty?
A: Yes, the product carries a Malarkey 10-year limited warranty.
Q: What installs over it?
A: Asphalt shingles or other approved steep-slope roof coverings install over this underlayment.
Q: How heavy is a roll?
A: The listed gross item weight is 75 lb, so plan for two-person handling.
Q: Is it algae resistant?
A: No, algae resistance is listed as No for this item.
Expert Verdict — Reviewed by the SuperArbor Pro Desk
SBS-modified underlayments like this Flexor roll give better cold-weather flexibility and nail-sealing than standard #30 felt, which is why they are common under premium shingle warranties. Roll it with the printed side out, maintain laps per the manufacturer's instructions, and confirm deck conditions and fastening patterns against ICC-ES ESR-3150. For a 30-square roof, order roughly 15 rolls plus waste.
Underlayment surfaces can be slippery, especially when wet or dusty; use fall protection and roof brackets when installing.
Order the Malarkey Right Start UDL Flexor 2-square roll for dependable SBS-modified protection under your next shingle roof.
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