ROOF MEMBRANE SEAMS INSPECTION
Modern roof seams are designed to provide many years of water-tight performance, but these seams are subjected to stresses which over time may produce water entry, especially at intersections and angle changes. Typically, field seams do not need to be inspected during the normal ten to fifteen warranty period unless observations of possible leakage have been observed. After the normal warranty period, it is advisable to completely renovate the field seams by re-covering with a new layer of seaming material.
WHERE EDMONTON ROOFING COMPANY WILL LOOK:
- "T"-Joints. "T" joints occur where two sheets of roofing membrane intersect. Because of the extra thickness of membrane at these locations, these joints may over time begin to open up due to the "memory" of the membrane.
- Angle Changes. Roof seams which travel through an angle change, such as a deck-towall joint, are subject to the same long-term stresses as "T" joints, and may begin to open up over time.
WHAT WE LOOK FOR:
- Edge Cavitation. The leading edge of the seam may be starting to open up, allowing dirt to accumulate in a cavity at the seam edge.
- Entrapped Moisture. Seams which are taking on moisture will typically exhibit "bubbling" along the seam edge when foot pressure is applied to the seam.
RECOMMENDED REMEDIAL PROCEDURES:
- Emergency Repair of Field Seams. Most single-ply field seams can be repaired temporarily by covering the seam edge with duct tape. Clean the membrane around the edge with a non- abrasive cleaner and apply a piece of duct tape extending beyond the affected area at least one inch in all directions. Most seams in modified bitumen membranes can be repaired temporarily by applying plastic roof cement to the seam edge. Make arrangements for a permanent repair as soon as possible.
- Permanent Restoration of Roof Seams. Restoration of aged roofing seams should be performed by a licensed roofing contractor.
- Single-Ply Seams. EPDM seams typically can be restored by "stripping in" the seam with a new covering of membrane material.
- Modified Bitumen Seams. Minor repairs to modified bitumen seams can be performed by pulling open the affected seam area and re-sealing the seam using a roofing torch. When seam deficiencies are widespread, the only effective long-term repair is the installation of a new layer of modified bitumen membrane over the affected roof surface area.