01 May 1999
b. Repair or Replace. Most thermoplastic membranes are reweldable throughout their life.
(However, CSPE cures and is more difficult to patch.) Repairs require compatible material preferably
from the same manufacturer as well as suitable heat welding equipment.
c. Repairs. The joint NRCA/ARMA/SPRI and RIEI maintenance manuals provide repair
guidelines, as does the literature of individual manufacturers.
(1) Emergency repairs. Use of a peel and stick elastomeric material or duct tape is
recommended. Asphalt mastic will serve in an emergency but the contaminated areas will have to be
removed to effect permanent repairs.
(2) Temporary repairs. Use of self-adhering butyl tape and other EPDM materials will provide
a temporary patch (even though the membrane is thermoplastic and the patch will eventually disbond).
(3) Permanent repairs. Permanent repairs consist of properly welded membrane. If the roof is
under warranty an authorized contractor must do the repair work.
d. Repair Work by User. In some cases, membrane manufacturers have trained building
maintenance personnel in proper repairs, provided tools and materials, and authorized them to serve
as approved contractors. This training program is especially useful at remote sites.
e. Maintenance Checklists. Use RIEI or ROOFER checklists for visual inspections. Perimeter
anchorage, flashings, penetrations, and roof drains are high priority items to check since most
problems originate there. Pulling of flashings, elevated membrane, and sheet distortion at
penetrations may indicate shrinkage. Embrittlement of some plasticized sheets has led to shattering.
Refer to the NRCA/SPRI Bulletin (Appendix 7-1) on this subject.