How To: Install GAF Liberty™ Low Slope Roofing System
GAF- Mastering The Roof (chapter 14)

The Liberty™ System is designed for both new roofing and re-roofing applications.
Full Installation Guide for Low Slope Modified Roofing (Cold-Applied Liberty System).
Low Slope Roofing Systems such as Liberty should only be installed on roof slopes of 2 in 12″ or higher. Never install it on roofs with ponding water.

This guide covers following procedures:

Deck Preparation
Base Ply Install
Middle Ply Install
Cap Sheet Installation
Drip Edge, Flashing and Accessory Installation details.

Low slope areas such as the roofs of carports, garages, porches and sun rooms – anything below a 2/12 pitch requires special attention.
Without the drainage of a steep slope, these roofs can take a hard beating from rain, ice and snow.

You’ve probably seen the problem leaks that occur where these low slope roofs tie in with the main house.

To provide you with materials that can meet these challenges, GAF has developed a series of self adhering membranes that go down easy, apply with simple tools and provide maximum protection. Lets take a look at these revolutionary low slope products and see how they install.

Liberty is a system for low slopes with a pitch between 1/2” to 6” per foot. Designed as a Whether installing Liberty Mechanically Attached Base Sheet, or Liberty Self Adhered Base Sheet, your edge metal details are the same.

At the edge of the roof, install drip edges. Primed Metal drip edge is required at eaves and rakes on Liberty Systems. At eaves and rakes, install a bed of Topcoat® Matrix 201 Premium SBS Flashing Cement to set the metal drip edge into. Next, to better seal the flange to the Base Sheet Base/Ply, nail the drip edge 3” on centers in a staggered pattern using roofing nails. Finally, apply a 1/16 to 1/8 inch troweling of Matrix 201 Premium SBS Flashing Cement to the top of the metal prior to installing the Liberty Cap Sheet over drip edges. Using a notched trowel helps assure a proper application rate of adhesive.

Working from the center of the length of Base Ply Sheet, allow the sheet to roll onto the primed deck, being careful to avoid wrinkles and trapped air while maintaining proper alignment with the selvage edge of the previous course.

Firmly hand press the sheet to avoid wrinkles and trapped air as the Base/Ply adheres to the underlying base sheet or primed deck.

Now fold the other half of the sheet back on itself exposing the remaining release film. Remove the release film and roll the sheet in place working from the center of the sheet outward towards the ends of the sheet.
Flashing of walls, roof terminations and penetrations can also be done with Liberty membranes and pre-flashed, SBS M-Weld Units.

As with all vertical flashings, the flashing is nailed off at the top and counter flashed.

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Liberty is just one of the self-adhered products offered by GAF. Others include the Freedom series of self-adhered TPO roofing membranes.
Freedom membrane is a tough commercial grade membrane that is easy to install, long lasting and energy efficient with a white reflective surface. For further information on self adhered roofing technology, visit GAF.com or call 1-800-ROOF-411. That’s 1-800-766-3411.