About LIBERTY™ Self‑Adhering Base/Ply Sheet

LIBERTY™ SBS Self-Adhering Roofing Systems are applied without torches, open flames, or hot asphalt, and are suitable for many primed substrates. LIBERTY™ Self-Adhering Base/Ply Sheet is a self-adhering modified bitumen roofing membrane intended to be used as either a base sheet for LIBERTY™ Self-Adhering Cap Sheet or as a ply sheet in modified bitumen roofing systems, providing long-lasting protection on low-slope roofs.

  • Convenient self-adhering installation eliminates open flames, hot asphalt, or dangerous chemicals on your roof
  • Reinforced with a glass mat which is coated with polymer-modified asphalt
  • Installed as a base sheet with LIBERTY™ Self-Adhering Cap Sheet or ply sheet for modified bitumen systems
  • Up to a 20-year limited warranty against manufacturing defects depending on system1


This product has earned the Good HouseKeeping Seal.


This product can be used to comply with certain FORTIFIED Roof™ requirements. Visit gaf.com/fortified and current FORTIFIED Home™ Standard available at fortifiedhome.org for details. Applicable in the U.S. only.

1See Limited Warranty on LIBERTY™ Self-Adhering Materials for complete coverage and restrictions.

Key Benefits

Serves as a Base Sheet for LIBERTY™ Self-Adhering Cap Sheet or Ply Sheet for modified bitumen roofing systems.

1See Limited Warranty on LIBERTY™ Self-Adhering Materials for complete coverage and restrictions

Video thumbnail showing a residential flat top roof.

The LIBERTY™ SBS self-adhering roll roofing system

This LIBERTY™ roofing system from GAF not only simplifies installation with convenient peel-and-stick components, it’s also available in nine popular colors to complement your Timberline® or other GAF asphalt shingles.

GAF LIBERTY™ product warranty

When installed as a complete system, our LIBERTY™ Limited Warranty covers up to twenty years of manufacturing defects available on select systems.* System guarantees covering material defects and workmanship errors are also available for purchase for approved systems installed by GAF certified contractors.**
*Exclusions apply. See Limited Warranty on LIBERTY ™ SBS Self-Adhering Materials for complete coverage and restrictions.
**See Low-Slope Addendum to the System Plus Limited Warranty, Low-Slope Addendum to the Silver Pledge ™ Limited Warranty, and Low-Slope Addendum to the Golden Pledge® Limited Warranty for complete coverage and limitations
Thumbnail of video showing GAF LIBERTY™ Self-Adhering Roofing System step by step

LIBERTY™ step-by-step installation video

Step-by-step instructions show you how to install a LIBERTY™ low-slope roofing system.
Illustration showing how a Class 4 shingle passes an impact-resistance test while a standard shingle fails.

This product has a UL 2218 Class 4 rating

UL 2218 impact testing involves dropping various sized steel balls onto tested materials from different heights and evaluating whether there are any cracks, tears, or fractures on the back surface of the product. Products that withstand the impact of a 2-inch steel ball dropped from 20 feet receive the highest rating, UL 2218 Class 4.
About impact resistance

Product Documentation

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LIBERTY™ SBS Self-Adhering 2-Ply Roofing System Installation — Step-by-step***

  1. GAF roof contractor repairing damage

    Step 1

    Inspect the roof, and repair or replace damaged areas.
  2. GAF roofing contractors rolling on LIBERTY Asphalt Primer.

    Step 2

    Apply LIBERTY™ Asphalt Primer at a rate of a 1/2 gallon per 100 sq. ft.
  3. GAF contractors installing LIBERTY SBS Self-Adhering Base/Ply on flat roof.

    Step 3

    Install LIBERTY™ Self-Adhering Base/Ply.
  4. Contractor applying LIBERTY Flashing Cement on exposed roof flange.

    Step 4

    Install edge flashing at all eave and rake edges, and apply LIBERTY™ Flashing Cement on exposed flange.
  5. GAF roofing contractors installing LIBERTY SBS Self-Adhering Cap Sheet on a flat roof.

    Step 5

    Install LIBERTY™ Self-Adhering Cap Sheet.

  6. Step 6

    Apply LIBERTY™ Flashing Cement on end laps, on exposed sheet and set the overlap back into place when applicable.
  7. Finished flat residential roof with GAF LIBERTY system.

    Step 7

    Clean up by removing tools, unused materials, and other debris. Plan on inspecting roof annually if possible.

***See application instructions for complete details. 

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