How to Install Liberty Low-Slope Rolled Roofing System

Are you looking to install a new low slope roof or do a re-roof on your home? With all the roofing products out there, it is really important to find one that will be reliable, durable, long lasting and leak-free for many years.

In the low-slope roofing market (roof pitch between 1 and 3 in 12), one product you can install yourself, is a Liberty roofing systems – an SBS modified bitumen roof. These systems are manufactured by GAF and are specially designed for low slopes with a pitch of 1/2 to 6 inches per foot. This product line consists of 3 membranes: the cap sheet and two base sheets: mechanically attached and self-adhering. You can either install one of the base sheets with the cap sheet on top, or for extra protection you can install the Liberty Premium 3 ply system, which includes the mechanically attached base sheet first, the self-adhering base sheet next and the cap sheet on top.

You can also use the Liberty roofing system for flashings at parapets, perimeter terminations, and typical roof-top penetrations, skylights.



Liberty Low-Slope Roof System overview:

Note: Liberty self-adhered rolled roofing system is a good product for DIY homeowners who do not have access to EPDM Rubber Roofing, and it is also easier to install and provides better puncture resistance than rubber roof.

Products like liberty are perfect for roof application on sheds, porches and other structures with low slope roofs, and they last a lot longer than traditional rolled asphalt roofing. However, liberty should never be used on completely flat roofs, or roofs without positive drainage, as this will not only void your warranty, but will also cause multiple roof leaks. For completely flat roofs, we recommend using PVC single-ply flat roofing membrane.

Installation of Liberty Rolled Roofing System:

Any roofing products is only as good as its installation, and Liberty products are no exception. Consequently, if you are installing the roof yourself, it is imperative to follow the right installation procedure to make sure that your new roof will be watertight. Our installation overview provides critical information you need to know prior to beginning your Liberty system roof installation.

To ensure proper adhesion of any Liberty self-adhered system it must be installed when the weather is dry and 45 degrees F. or higher. Liberty 2 & 3 ply systems are accepted and covered by the Golden Pledge and Systems Plus Ltd. warranties on low slope areas of shingle projects.



Take care of the substrate prior to installation

To ensure that your installation goes smoothly and successfully, the substrate must be clean and dry.
The substrate for the Liberty system must be clean and dry. All penetration curbs, perimeters, “kents, nailers”, must be in place???

Installation of Liberty Mechanically Attached Base Sheet (Liberty MA Base)

Liberty Mechanically Attached Base Sheet is a one meter or 39 and 3/8 inch wide membrane with a plastic film on top, designed to maximize the attachment of other self-adhering Liberty Membranes. This sheet can be mechanically attached directly to the deck or installed over ISO insulation. Over nailable decks, the sheet can be nailed with a typical base sheet pattern, using 1 inch square or round cap metal nails.

Important installation tips:

-You should let the sheet relax and remove any wrinkles to provide the smoothest surface for other plies.

-All Liberty systems require installation of primed metal drip edges on eaves and rakes.

– Make sure you use the correct adhesives and cements with Liberty roofing systems. All of them require the the use of SBS Adhesives and cements, as other none-SBS cements may have an adverse reaction and damage the Liberty membranes.

– To create additional wind uplift resistance, apply a bead of caulk in the overlap between the base sheets, and then nail the the overlap area a minimum of 6 inches on center.

– To reduce the risk of leaks, you should off-set the end laps in the adjacent course a minimum of 36 inches.

Installation of the Liberty Self Adhering Base Sheet

The Liberty Self-Adhering Base sheet is also a 1 meter or 39.375 inch wide membrane that has a plastic film top surface designed to receive the liberty cap sheet. On the bottom, the surface is a split back release film, designed to to be removed to uncover a self-adhering surface. Often, the self-adhering base sheet is a more popular choice, due to easier and quicker installation as compared to the mechanically attached base sheet. One major advantage of the self-adhering membrane is that it has superior self – adhering properties.

How to achieve the strongest adhesion bond during installation

When installed, directly to wood, the membrane will adhere very strongly. While it is possible to achieve decent adhesion to wood, without primer, the best and most long lasting adhesion can be achieved, if you prime the wood with one coat of matrix 307 asphalt concrete primer or a comparable ASTM D-41 type primer. It is important to allow the primer to dry completely prior to the installation of the self-adhering base sheet. This gives the self-adhering membrane an asphalt surface to bond to, so when the deck moves, the self-adhered base sheet can move with it. Priming is option, if you are applying the self-adhering membrane to the mechanically attached base or a wood deck.

Important installation tips:

– During installation, firmly press the sheet to avoid wrinkles and trapped air, as the ply adheres to the deck or to the mechanically attached base sheet, and press down the faccia.

– When adding additional length of Liberty base ply to the same course, you need to overlap the end of the previous sheet a minimum of 6 inches, which will create the best protection against leaks.

– After you finish applying the Liberty self-adhesive base sheet, apply uniform pressure to the entire area by using a either a long-handed push broom or a weighted roller. Do not skip this step, as this will ensure a solid bond between plies. Brooming also provides a clean surface for adhesion of the liberty cap sheet.

Installation of the Liberty Cap Sheet

Important installation tips:

– Before installing the cap sheets, let them relax on the roof. By allowing the ends of the rolls to lay flat, you ensure a much better finished look.

– To seal one row with another and to minimize the possibility of “lack blisters” forming, apply a bead of Leak Buster Matrix 201 Premium SBS flashing cement adhesive along the top edge of each cap sheet and of any salvaged edge T joints in any self-adhered system.

– It is required to install a bead of Leak Buster Matrix 201 Premium SBS flashing cement at the top of each Liberty Cap Sheet course on all Golden Pledge Installations.

– To prevent membrane movement on roof slopes with a rise greater than 1 inch in 12, back nail in the salvage area at 18 inches on center with roofing nails or cap nails.

– It is highly recommended to leave a minimum of 8 inches of release film on the back of the overlapping cap sheet. This prevents unwanted bonding to the granular surface of the underlying sheet when installing the adjoining sheet.

– To ensure proper adhesion of the cap sheet, apply uniform pressure to it using a broom or a weighted roller.

-If you have any remaining adhesive bleed out, you can cover it with loose granules, to achieve a more professional and nice-looking appearance.