Single Ply Membrane

Single-Ply Membrane

1. General Product Information

1.1 Product Type
1.2 Roofing Categories
1.3 Product Manufacturers
1.4 Manufacturing Process
1.5 Industry-Specific Standards, Codes Requirements, and Compliance
1.6 Unique Industry-Specific Flashing and Metal

1.1 Product Type

1.1.1 Thermoset Membranes

Thermoset membranes are compounded from rubber polymers. The most commonly used polymer is EPDM (ethylene propylene diene monomer [M-class]; often referred to as "rubber roofing"). Another thermoset material is neoprene, although this particular formulation is no longer widely used for roofing. Thermoset membranes have proven their ability to withstand the potentially damaging effects of sunlight and most common chemicals generally found on roofs.

1.1.2 Hypalon

Hypalon is a unique material because it is manufactured as a thermoplastic, but because it cures over time, it becomes a thermoset. Hypalon materials are heat-sealed at the seams. Hypalon is not a widely used material today.

1.1.3 Thermoplastic Membranes

Thermoplastic membranes are based on plastic polymers. The most common thermoplastic is TPO (thermoplastic olefin), which is the fastest growing single-ply membrane type. Another common thermoplastic membrane is PVC (polyvinyl chloride), which has been made flexible through the inclusion of certain ingredients called plasticizers. A number of different products in this category are available including KEE (ketone ethylene ester), each having its own unique formula. Thermoplastic membranes are identified by seams that are formed using either heat or chemical welding. These seams are as strong as or stronger than the membrane itself. Most thermoplastic membranes are manufactured to include a reinforcement layer, usually polyester or fiberglass, which provides increased strength and dimensional stability.

1.1.4 Modified Bitumen Membranes

Modified bitumen membranes are interesting hybrids that incorporate the high-tech formulation and prefabrication advantages of single-ply with some of the traditional installation techniques used in built-up roofing. These materials are factory-fabricated layers of asphalt, “modified” using a rubber or plastic ingredient for increased flexibility, and combined with a reinforcement layer for added strength and stability. There are two primary modifiers used today: APP (atactic polypropylene) and SBS (styrene butadiene styrene). The type of modifier used may determine the method of sheet installation. Some are mopped down using hot asphalt and some use torches to melt the asphalt so that it flows onto the substrate. The seams are sealed by the same technique.

1.1.5 Product Quality

Manufacturers of single-ply roof membranes maintain Product Evaluation reports (also referred to as Research Reports) issued by qualified agencies. These reports contain a quality control section which states:

The products shall be manufactured under an approved quality control program with inspections by an inspection agency accredited by the International Accreditation Service (IAS) or otherwise acceptable to ICC-ES.

A quality control manual complying with the ICC-ES Acceptance Criteria for Quality Control Manuals (AC10) shall be submitted.

1.1.6 Identification and Traceability

1.1.7 Packaging

Single-ply roll goods are typically placed in shrink bags, which may contain the product name, mil thickness, and code compliance and standards. Safety and Department of Transportation info is generally supplied as well.

1.2 Roofing Categories

1.2.1 Low Slope

1.2.2 Steep Slope

1.2.3 Roof Pitch Limitations

Single-ply roof membranes can be used on any slope as long as the roofing assembly they are used in has been tested in accordance with test procedures approved by the authority having jurisdiction and meets the stated fire classification requirements. The IBC requires that single-ply roof membranes have a design slope of not less than 1/4:12

1.2.4 Substrates and Finishes

Metal is the most common roof deck material used with single-ply roof membranes.

1.3 Product Manufacturers

1.3.1 Current Manufacturers

Please see the referenced web link for a list of manufacturers and the products they produce.

1.3.2 Industry Trade Associations

Single Ply Roofing Industry (SPRI; represents sheet membrane, related component suppliers, design professionals and testing laboratories in the commercial membrane roofing industry. It is the recognized technical and statistical authority in the single-ply roofing industry. Since 1981, SPRI has provided a forum for its members to collectively focus their industry expertise and efforts on critical industry issues. The group effectively works to improve product quality, installation techniques, workforce training and other issues common to the industry. SPRI is an excellent resource for building owners, architects, engineers, specifiers, contractors and maintenance personnel, providing objective information about commercial roofing components and systems. The SPRI website provides many valuable resource documents, ranging from technical guidelines for design and applications to general information about roof maintenance and emergency repairs.

Chemical Fabrics and Film Association (CFFA; is an international trade association representing manufacturers of polymer-based fabric and film products used in the building and construction, automotive, fashion and many other industries. This association represents thermoplastic single-ply roof membranes and is an excellent resource for information on the durability, sustainability and aesthetics of thermoplastic roof membrane systems.

The EPDM Roofing Association (ERA; was established in 2003 to provide the construction and roofing communities with current and accurate data documenting the many benefits of EPDM roofing systems. It was established in response to environmentalists and code regulators placing more emphasis on the long-term performance of building materials. The association is an excellent source of information on the performance and sustainability of EPDM roofing systems.

1.4 Manufacturing Process

1.5 Industry-Specific Standards, Codes Requirements, and Compliance

1.5.1 Hail

1.5.2 Wind

Databases of uplift resistance test results for single-ply roof membrane systems are maintained by the testing agencies that conducted the tests. The most commonly referenced database is ROOFNAV, developed by FM Approvals, and is available at; registration is required for access. SPRI is currently developing a database that would include all wind uplift test results in one location regardless of the testing lab they were conducted at, as long as it is a code-approved facility.

Wind speed warranties may be available through the single-ply roofing system manufacturer or supplier. The warranted wind speed can vary and may or may not correspond to the Basic Wind Speed established for a given location. Consult the system manufacturer/supplier for specific warranty details and limitations.

1.5.3 Fire

1.6 Unique Industry-Specific Flashing and Metal

Coming soon...

Coming soon...

Coming soon...

Coming soon...

Disclaimer: This manual has been prepared for informational purposes only. RICOWI, IBHS, and the participating roofing industry organizations expressly state that they have no liability, in negligence, tort, or otherwise, with respect to the use of any of the information and/or practices described in this article. The information set forth in this manual is provided in good faith. The user assumes the sole risk of making use of the information provided in this manual.

Users of this manual are strongly urged to follow accepted safety practices, refer to applicable local building codes and standards, and relevant manufacturers’ instructions for appropriate technical requirements, and to work with a qualified professional in order to operationalize the information contained herein. Photographs and examples contained in this manual are provided for illustrative purposes only and do not guarantee the condition of any specific product or the effectiveness of any repair or installation. Nothing contained in this manual is intended or written to be used, nor may it be relied upon or used, by any person and/or business as legal advice.

NOTE: The manual is being completed in sections, and will be released in stages. Check back often to see the most up-to-date edition of the guide.
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