Leak Barriers - UnderRoof 2

UnderRoof™ 2 Waterproof Protection Under Tile Roofs

Because Tile Roofs Are Not Watertight, You Need A Self-Adhering Premium Leak Barrier

To protect against leaks, contractors typically nail one or two layers of “tar paper” to your roof before they install the tile. But “tar paper” doesn’t provide much protection because it’s made with conventional organic felt, which can become saturated with water and reduce its ability to prevent leaks. So even though you pay a large premium for a tile roof, your home — your most valuable asset — is potentially left vulnerable to water damage.

UnderRoof™ 2 Waterproof Protection is a specially-designed self-adhering leak barrier for tile roofs.

It provides maximum protection from leaks that can result from tile saturation, clogged gutters, wind-driven rain, or (in cold climates) freeze-thaw damage. Made with flexible SBS-modified compound and reinforced with a fiberglass-reinforced polyester core, UnderRoof™ 2 Waterproof Protection applies easily and can be left exposed for up to 180 days, if necessary. The heat-activated adhesive allows the product to be repositionable for ease of installation, but seals tightly once in place, providing a watertight barrier against leaks.

Good Housekeeping

UnderRoof™ 2 Leak Barrier is a key part of the GAF Lifetime Roofing System, and has even earned the prestigious Good Housekeeping Seal. (See Details)

Installation Considerations
(before installing)

  • Review Application Instructions...
    On packaging as well as detailed instructions available at your place of purchase, at www.gaf.com, or by calling GAF Technical Services at 1-800-766-3411. Also be sure to carefully review the tile manufacturer’s application instructions.

  • Substrates...
    Should only be installed over clean, dry surfaces, including unwrinkled underlayment, such as GAF Deck-Armor™ or ASTM D 226 #30 organic felt, or directly to flat substrates, such as plywood. Contact GAF Technical Services for suitability of other substrates.

  • Temperatures...
    Should be installed when temperatures are 45°F (17.8°C) or higher.

  • Venting...
    In applications over the full deck, it is particularly important to be sure that the roof assembly/attic is properly ventilated.

Homeowner’s Best Choice

  • Superior Protection...
    Waterproof membrane provides better protection than standard “tar paper”

  • Less Chance Of Leaks...
    Unlike conventional “tar paper,” each layer seals to the next, helping to prevent water infiltration

  • Seals Better...
    SBS-modified asphalt self-seals when penetrated by nails or fasteners

  • No Unpleasant Fumes Or Flames...
    Eliminates the need for hot asphalt or open flames on your roof

  • Less Disruption...
    Installs up to 50% faster than hot asphalt-based systems

  • Peace Of Mind...
    Up to a Lifetime ltd. warranty when used on Lifetime Shingle roofs, up to a 25-year ltd. warranty when used on non-Lifetime Shingle roofs, and up to a 10-year ltd. warranty when used with other approved roof coverings. (See Details)

Professional’s Best Choice

  • Safer For Installers...
    Installs without the need for hot asphalt or torches

  • Slip Resistant...
    Polyester surfacing provides enhanced skid resistance

  • Easier To Install..
    Flexible design conforms to irregular surfaces to help prevent leaks, even at the most vulnerable areas of the roof — like around chimneys, plumbing vents, and skylights

  • Proven Technology...
    Based on the same technology as GAF’s modified bitumen self-adhering leak barriers

  • Convenient...
    If necessary, can be left exposed for up to 180 days


Product Specifications (Nominal)

Roll Length 67.8 ft (20.7 m)
Roll Width 39.4 in (1.0 m)
Gross Square Feet Per Roll 222.5 sq ft (20.6 sq m)
Approx. Coverage Per Roll 200 sq ft (18.6 sq m)

Applicable Standards

  • ICC Pending
  • Meets the performance criteria of ASTM D1970
  • Miami-Dade County Approved
  • State of Florida Approved


All documents are U.S. English unless otherwise noted

Get Automatic Lifetime Protection On Your GAF UnderRoof™ II Leak Barriers and Your Entire GAF Roofing System!

  • A Lifetime ltd. warranty... on your shingles and all qualifying GAF accessories! (See Details)
  • Non-prorated coverage for the first 10 years (See Details)

Professional Installation

GAF Roof Wizard
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