Platinum Roofing was asked to replace the roof at 909 Montgomery Street in San Francisco. This building has a unique roof system known as an inverted roofing membrane assembly, or IRMA. In this type of roof, an assembly consisting of EPDM (rubberized material) is adhered to a concrete substrate with 3 1/2 inches of insulation placed over it, which is held down with netting and a gravel ballast. The beauty of an inverted membrane assembly is that the insulation on top protects the membrane below from solar degradation. This significantly increases the service life of the roof.
The job, however, was not without challenges. The crew had to get all of the roofing components off the roof and back on without disturbing the tenants, who worked very long hours. The multiple office balconies had concrete pavers for foot traffic on top of the gravel. The pavers were artistically arranged and had to be painstakingly placed back exactly as they were. Because of the limited access, the roofing gravel had to be washed on the roof so it could be re-used. It was a very tedious job with a very small window of time in which to do it.
The crew at Platinum completed the job on time with minimal disruption. After having gone through one winter, Platinum Roofing is pleased to report that there has not been a single problem with this great looking power-house of a new roof.