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U.S. Gypsum SecuRock Glass-Mat Roof Board 5/8 in. x 4 ft. x 8 ft.
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U.S. Gypsum SecuRock Glass-Mat Roof Board 5/8 in. x 4 ft. x 8 ft.
U.S. Gypsum SecuRock Glass-Mat Roof Board is a 5/8-inch-thick, 4 ft. x 8 ft. glass-mat gypsum roof cover board, one piece per order unit at about 88 lb. It provides a durable thermal barrier and cover board layer in low-slope roof assemblies, installed under or over the membrane per the roof system design.
Key Features:
- 5/8 in. glass-mat board: Glass-mat gypsum core faced for strength and moisture resistance in roof assemblies.
- 4 ft. x 8 ft. board: Standard 4 ft. x 8 ft. panel size for efficient layout on low-slope roofs.
- UL Classified, FM Approved: UL Classified and FM Approved per the listed standards.
- ICC-ES ESR 3044: Covered by ICC-ES evaluation report ESR-3044.
- Multiple ASTM standards: Applicable to ASTM D3273, E84, E136, C1177 and E96.
- Thermal barrier / cover board: Used in roof assemblies as cover board and thermal barrier per the roof system design.
Specifications Table:
| Specification | Details |
|---|---|
| Brand | U.S. Gypsum |
| Manufacturer model | 221852 |
| Sell unit | 1 board, 5/8 in. x 4 ft. x 8 ft. |
| Product line | SecuRock Glass-Mat Roof Board |
| Dimensions | 5/8 in. x 4 ft. x 8 ft. |
| Thickness | 5/8 in. |
| Width | 4 ft. |
| Length | 8 ft. |
| Material | Glass-mat gypsum |
| Applicable standards | ASTM D3273; ASTM E84; ASTM E136; ASTM C1177; ASTM E96; ICC-ES ESR-3044; UL Classified; FM Approved |
| Weight | 88 lb |
| Intended use | Roof cover board / thermal barrier in low-slope roof assemblies |
| Product category | Roofing Insulation |
Coverage & How Much You Need:
One 5/8 in. x 4 ft. x 8 ft. board covers 32 sq ft of roof area. Divide total roof square footage by 32 (before fasteners, laps and waste) to estimate board count for a job.
Fit and Compatibility:
Installed in approved low-slope roof assemblies over roof insulation or deck and under (or above, per system design) the membrane; coordinate with the membrane manufacturer's cover board acceptance and fastening requirements. Adhesive and fastening plates are sold separately.
Frequently Asked Questions (FAQ):
Q: What size is each board?
A: Each board is 5/8 in. thick and 4 ft. x 8 ft., covering 32 sq ft.
Q: How much does one board weigh?
A: Approximately 88 lb per board.
Q: What is it used for?
A: It serves as a cover board and thermal barrier layer in low-slope roof assemblies.
Q: Is it code evaluated?
A: It is listed with ICC-ES ESR-3044, UL Classified and FM Approved, plus ASTM D3273, E84, E136, C1177 and E96.
Q: How do I size my order?
A: At 32 sq ft per board, divide your roof area by 32 and add waste per the installer's standard practice.
Expert Verdict — Reviewed by the SuperArbor Pro Desk
SecuRock glass-mat roof board adds impact resistance and dimension stability beneath single-ply membranes, and its UL/FM listings support many rated assemblies — always match the exact assembly in ESR-3044 or the FM approval guide. Stagger board joints, fasten per the roof system manufacturer's spacing, and keep boards dry before the membrane goes on. Confirm wind uplift design with your fastening pattern.
Boards are heavy (about 88 lb) and gypsum dust is produced when cut — use two-person or mechanical handling and wear dust protection and gloves.
Order U.S. Gypsum SecuRock Glass-Mat Roof Board 5/8 in. x 4 ft. x 8 ft. for your low-slope roof assembly.
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