Thinking outside the seam

Electromagnetic induction welding systems offer an alternative to mechanically fastened roof membranes


Induction welding technology used for roof membrane attachment began in Europe and has been available in the U.S. for about 15 years. Currently, several U.S. roofing manufacturers offer induction welding-installed systems for TPO and PVC roof membranes. A roof assembly using induction welding is similar to a traditional system where fasteners and plates are used to attach insulation to a structural deck. But unlike a traditional system, a roof membrane is bonded to fastening plates without membrane penetration or a fastener line at the membrane sheet seams.

Systems

An induction welding system uses fasteners and coated plates to secure roof board insulation to a structural deck. A TPO or PVC membrane then is attached from above the roof membrane to each plate with an electromagnetic induction welding tool.

At press time, eight manufacturers offer induction welding-installed systems that achieve FM Global's wind-resistance rating when tested as part of a roof assembly. Each manufacturer has an agreement with OMG Roofing Products, Agawam, Mass., to produce fasteners and coated plates for their specific systems, as well as Rhino-Bond® Tool—a stand-up electromagnetic induction welder used on roofs to create a bond between a coated fastener plate and the underside of a roof membrane. For a list of manufacturers currently offering induction welding-installed systems for thermoplastic roofing, see the figure on page 41.