DiamondDeck

DiamondDeck is a CertainTeed High Performance Synthetic Underlayment. It is a synthetic polymer-based, scrim-reinforced sheet used on roof decks as a water-resistant layer beneath asphalt roofing shingles, wood shingles and shakes, metal shingles and panels, or slate.

The top surface carries printed diamond-shaped targets that mark the nailing locations, and a surface treatment for slip resistance.

• Roll width: 4 feet.
• Roll length: 250 feet.
• Roll area: 1000 square feet.
• Thickness: 14 mils.
• Shipping weight: 37 pounds per roll.

Its dimensional stability when wet exceeds that of standard asphalt felt underlayment, and it does not wrinkle from hygro-expansion.

Plastic cap nails with a 1-inch head are required. Staples are not used. Approved fasteners can be pneumatically driven or hand applied.

• On slopes from 2 inches per foot up to 4 inches per foot, the low slope application instructions in the CertainTeed Master Craftsman Shingle Applicator's Manual apply.
• It is not installed as ice dam protection along eaves. Two layers of DiamondDeck cemented together are not equivalent to CertainTeed WinterGuard or Vycor.
• It is not designed to be permanently exposed or used as a waterproofing underlayment.
• It is tested for UV resistance for up to 180 days and is not exposed for more than 6 months before the finished roofing is installed.
• Rolls are stored horizontally on the pallet, or standing on end after opening, in a dry, protected area below 120 degrees F.

DiamondDeck meets the physical property requirements of the following:

• ASTM D226 Type II, ASTM D4689 Type IV and ASTM D8257.
• CSA A220.1 and CSA A123.3.
• ICC Acceptance Criteria AC 188 and ICC-ES ESR 3344.
• Florida State Product Approval and Miami-Dade Product Control approval.
• Texas Department of Insurance Product Evaluation listing.
• UL 790 and ASTM E108 Class A when installed in a system beneath Class A shingles listed to ASTM D3462.

The sheet is constructed from a polypropylene and polymer composite with scrim reinforcement. It is part of the CertainTeed Integrity Roof System and is designed to work with CertainTeed roofing shingles.

• Applicable roofing: shingle, shake, metal and slate
• Surface: slip-resistant
• Listed properties: fire resistant, wind resistant, tear resistant, wind driven rain resistant

DiamondDeck is among the underlayments used under residential shingle roofing products. CertainTeed underlayments are covered by a manufacturer's product limited warranty. The data sheet is dated 08/26.