Grace Tri-Flex 15 - Synthetic Roof Underlayment - 4' x 250' Roll

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Quick ID: Q26108
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  • Synthetic replacement for #15 felt
  • Better coverage per roll and 10x stronger than traditional #15 felt underlayment
  • 100 % recyclable
  • Mechanically fastened with capped nails or staples
  • Available in 10 sq. rolls (48 in. wide x 250 ft. long)
  • Up to 60 days exposure
  • Meets ASTM D226, FBC, and AC-188 code standards


Tri-Flex 15 is a synthetic roofing underlayment coated with polypropylene on both sides and offers many benefits to traditional #15 felt. This proprietary resin formula is used in the walk and deckside surfaces to create a slip resistant surface. It is 10x stronger than the #15 felt and prevents blow offs and tears in windy conditions. It is considered impermeable and will not allow water vapor to pass through it. A 10 square roll is 67 percent lighter than #15 felt, and covers 2.3 times the area. This sustainable product is 100% recyclable and contributes to sustainability and LEED. It exceeds the requirements of ASTM D226 type 1 and II.

Tri-Flex 15 is used with asphalt shingles or most other roof coverings as a secondary watershedding material. It may be exposed up to 60 days and can be used alone or in combination with Grace self adhered underlayments.


Manufacturer Part Number112737
Sub BrandGCP Applied Technologies
Code ApprovalAC-188 Acceptance Criteria for Roof Underlayments, Florida Building Code Requirements, ASTM E108/UL 790 for use in the installation of Class A asphalt glass fiber mat shingles and Class C asphalt organic felt or metal shingles, and meets ASTM D226 physical requirements of Type I and Type II
Coverage - Square Feet1000
Installation MethodMechanically fastened with capped nails or staples; Laid horizontally, starting at bottom of roof with print side up; Side laps must be minimum of 4 in. and end laps minimum of 6 in.
Installation Tools RequiredCapped nails or staples having 1-inch diameter plastic/metal caps - spaced at 8 in. OC on both side and end laps. High wind and coastal zones - double fastening to 4 in. OC; All cases - fasten at 24 in. OC down middle of roll in the field of the roof
Length - Feet250
Moisture Vapor Permeance0
Package Quantity1
Thickness - Inches7 mil
Warranty25 Year
Width - Inches48
Ships to HI/AKNo

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