FAQs

WOULD A MANUFACTURER’S WARRANTY BE TERMINATED DUE TO PONDING?

Ponded water on an EPDM roofing system will not void a manufacturer’s warranty or be the sole reason to deny issuance of a warranty. During the design phase, however, efforts should be made to incorporate positive drainage into the roofing assembly to avoid excessive ponding. It is beneficial to avoid ponding water due to the expense associated with its removal in the event of repairs and also to reduce moisture infiltration and damage in the event of incidental puncture.

REGARDING AGED EPDM MEMBRANE, WHAT TYPE OF SURFACE PREPARATION IS NEEDED TO PERFORM ANY NEEDED REPAIRS?

Because EPDM is a thermal set membrane at the time of installation, no additional curing will occur. Repairs can easily be performed with simple tools and accessories without the need of heavy-duty equipment.

For example, a cut or tear can be repaired by cleaning the membrane surface to remove field dirt (brooming in addition to washing with low sudsing soap and rinsing). The area is then primed and a laminated patch is used to seal the cut or tear.

WHAT TYPES OF IMPROVEMENTS HAVE BEEN MADE TO EPDM SPLICING TECHNOLOGY?

The introduction of membrane splice tapes as an option to the use of liquid adhesives has resulted in less reliability on contractor workmanship, increased production for the contractor, and enhanced performance for the roofing system and building owner.

Laminated components (flashing components that have a pre-applied adhesive tape) have improved flashing quality (an item that has traditionally been problematic).

Equipment utilized to install EPDM single-ply roofing systems has also evolved as well. Innovations have been made to ease the backbreaking work of roof installations – this helps reduce work force fatigue and enhances the installation and performance of the roofing system.

HOW IS EPDM MEMBRANE SPLICED TOGETHER?

Two methods of splicing are currently available using either liquid adhesive or splice tape.

When using liquid adhesive, adjoining sheets are cleaned with the manufacturer’s recommended splice cleaner prior to applying the splicing adhesive. A sealant is used along the edge of the splice and is applied after allowing solvent in the adhesive to flash off (minimum 2 hours). Some manufactures have also used an additional sealant within the overlapping area that is applied immediately before putting the splice together. The sealant is intended as a secondary protection to guard against moist penetration in the event of workmanship error at intersections with factory seams.

The second method of splicing was developed to speed up the seaming processing while maintaining consistent application across the entire seam. This process introduced the use of an adhesive tape in conjunction with a splice primer. The adjoining membranes are primed then the tape is applied once the primer has dried. No additional sealant is used along the edge of the splice. This method has become more favorable due to application consistency.

DO I HAVE TO WORRY ABOUT STAIN HARDENING AND POTENTIAL DETERIORATION IN THE FUTURE WHEN A HAIL STORM COMES IN CONTACT WITH MY EPDM ROOF?

Neither manufacture of EPDM has seen evidence of strain hardening in EPDM membrane at anytime in there life.

WHAT CAN I PUT ON SNOW AND ICE TO FACILITATE MELTING AND ONE EFFECT THE EPDM OR MY WARRANTY?

Calcium Chloride will work in most conditions. It can either be spread over the area of concern or placed in a nylon stocking and placed along/around the areas in need of melting. While the Calcium Chloride will not harm the EPDM caution should be taken in regards to where the melt water run will drain, and verification that it will not affect the materials and or vegetation it comes in contact should be obtained prior to placing the Calcium Chloride on the roof.

ARE THERE STANDARD DETAILS FOR USE WITH EPDM SYSTEMS?

Yes. The National Roofing Contractors Association (NRCA) and the Single-Ply Roofing Association (SPRI) publish standard details. However, manufacturers may have modified versions of these details which may not exactly match.

IS THERE AN ASTM STANDARD FOR EPDM MEMBRANE?

Yes, ASTM D 4637.

HAVE THE ASTM STANDARDS FOR LINEAR DIMENSIONAL STABILITY (FOR EPDM) BEEN MODIFIED?

The ASTM standard for linear dimensional stability (ASTM D 1204) was originally 2% maximum. In the mid-90s the standard was changed to 1% maximum. The change in the ASTM standard was influenced by the belief that membrane shrinkage may be a contributor to the bridging seen on some old ballasted applications. In reality, EPDM has always exhibited a dimensional stability value of much less than 1%, even when the ASTM Standard was 2%.

WHAT IS THE CAUSE OF BRIDGING THAT HAS BEEN SEEN IN THE PAST AT ANGLE CHANGES IN SOME EPDM LOOSE-LAID APPLICATIONS?

Some membrane bridging has been observed in the past in some loose-laid ballasted membrane assemblies. The bridging was not seen in adhered or mechanically-fastened applications where the membrane is adhered or secured in place. The cause of this bridging relates to membrane movement experienced in ballasted roofing systems and insufficient securement in the angle change at the base of parapets. This phenomenon was not seen in every ballasted loose-laid assembly but only some (mostly in colder regions) where improper securement is present. Examples include:

Roofing nails used to anchor the roofing membrane to a horizontal wood nailer
Improperly anchored beveled wood nailers fastened to the vertical wall (warping and buckling of the wood occurred)
Rubber nailing strips fastened horizontally or vertically
In 1987, the method of securement was changed to incorporate 2″ diameter plates and threaded fasteners spaced at 12″ on center or a reinforced strip (glued to the underside of the roofing membrane at the angle change) to anchor the roofing membrane. This change in securement method eliminated the bridging. Both NRCA and SPRI have endorsed this securement.