Gear & Build Pro-Grade Synthetic Underlayment
Gear & Build Pro-Grade is a cross-woven synthetic roofing underlayment for metal and asphalt shingle roofs — tougher, lighter, and faster to install than felt. Each 10-square roll lays flat, walks slip-resistant underfoot, protects the deck for up to 180 days of UV, and stays stable from -40°F to 240°F.
Price
$150.00/ roll
Volume pricing
| Quantity | Per roll |
|---|---|
| 1–9 | $150.00 |
| 10–24 | $142.50 |
| 25+ | $135.00 |
Add 9 more to unlock $142.50 / roll.
Product overview
Gear & Build Pro-Grade is a cross-woven polypropylene synthetic roofing underlayment built for the way professional crews actually work: rolled out fast, walked on all day, fastened through wind, and sometimes left exposed longer than anyone planned. One roll delivers complete roof deck protection across ten full squares at a quarter of the weight of the felt it replaces — a tougher, lighter, faster alternative to #15 and #30 asphalt felt.
Engineered for professional installation
The top surface carries a slip-resistant, walkable coating that keeps its grip underfoot on dusty decks, steep pitches, and early-morning dew. Printed overlap guides and a printed fastening pattern take the guesswork out of course alignment, so newer crew members run straight lines without supervision. The sheet lays flat off the roll and stays flat — no wrinkling or buckling after overnight moisture, which means the deck you paper on Friday is the deck you shingle on Monday.
High-temperature performance for metal and steep-slope roofs
An inert synthetic sheet stays serviceable from -40°F to 240°F, so it holds up under metal panels and in hot-climate assemblies where asphalt felt bakes, dries out, and cracks. It will not rot, wrinkle, absorb water, or support mold growth, and it will not leach oils in the heat. That high-temperature stability makes Pro-Grade suitable under asphalt shingles, metal roofing, synthetic slate and shake, and other steep-slope coverings.
Performance in every layer
A cross-woven scrim core gives Gear & Build Pro-Grade 85 lbf of tear strength (ASTM D4533), so caps stay anchored through foot traffic and wind events instead of tearing free. The coated sheet is an effective moisture barrier that protects the deck and the structure below it from dry-in until final roofing, and it carries a 180-day UV exposure rating for jobs where the schedule slips.
Features & benefits
Key features
- Cross-woven polypropylene scrim resists tearing at fasteners, even under heavy foot traffic
- Slip-resistant, walkable top coating keeps its grip on dusty decks, steep pitches, and morning dew
- High-temperature stable from -40°F to 240°F — rated for metal roofing and hot-climate assemblies
- Printed overlap guides and fastening pattern speed up course alignment and QC
- 180-day UV exposure rating protects the deck through schedule delays
- 10-square rolls at 24 lb — four times the coverage of a felt roll at a fraction of the weight
- Inert synthetic sheet will not rot, wrinkle, absorb water, or support mold growth like felt
Benefits
- Complete roof deck protection: keeps the deck and structure dry from dry-in to final roofing
- Faster dry-in: crews cover more deck per hour than with 15-lb felt
- Fewer ladder trips — one roll papers ten squares
- Lays flat and stays flat for cleaner shingle lines
- Stands up to jobsite foot traffic without pulling through at the caps
- Keeps the structure dry through weather delays of up to 180 days
- Lighter rolls reduce crew fatigue and handling injuries
Applications
- Asphalt shingle roofs on slopes 2:12 and steeper (double coverage below 4:12)
- Metal roofing assemblies, including high-temperature applications to 240°F
- Synthetic slate, shake, and composite steep-slope systems
- Tile roofs where approved by the tile manufacturer
- Residential re-roof and new-construction projects
- Light commercial steep-slope assemblies
Specifications
Physical Properties
| Roll size | 48 in × 250 ft (10 squares) |
|---|---|
| Net coverage | 1,000 sq ft (10 squares) per roll |
| Roll weight | 24 lb |
| Thickness | 8.5 mil |
| Top surface | Slip-resistant, walkable (steep-slope rated) |
| Material | Cross-woven polypropylene with slip-resistant coating |
Performance
| Tear strength (ASTM D4533) | 85 lbf |
|---|---|
| Tensile strength (ASTM D5035) | 120 lbf/in |
| UV exposure rating | 180 days |
| Temperature range | -40°F to 240°F |
| Fire classification | Class A (with approved assemblies) |
Compliance
| Code listings | ICC-ES ESR [PLACEHOLDER — final report number] |
|---|---|
| Standards | ASTM D226 / D4869 / D8257 alternative |
Installation
Install Gear & Build Pro-Grade over a clean, dry, properly fastened deck. Roll out parallel to the eave with the printed side up and align the first course with the drip edge.
Horizontal laps: minimum 4 in on slopes 4:12 and steeper; use a 24 in lap (double coverage) on slopes between 2:12 and 4:12.
End laps: minimum 6 in, staggered at least 6 ft between courses.
Fasten with 1 in plastic cap nails or cap staples: every 8–12 in along the printed lap lines and two staggered rows at 24 in on center in the field.
Tighten to the enhanced fastening pattern printed on the sheet for extended exposure or high-wind regions.
Install code-required self-adhered ice-and-water membrane at eaves, valleys, and penetrations before the field courses.
The printed instructions on each roll, local code, and the primary roof covering manufacturer's instructions govern where more restrictive. See our installation guide article for the full crew checklist.