Custom Made Flat Roof

From residential flat roofs to industrial warehouses, Built-up roof systems (BUR) have long been the low slope roof solution in the San Francisco Bay Area. These custom-made roof systems are built on the roof deck providing a solid surface roofing membrane.

What is a Built-up Roof?

Often referred to as โ€œtar and gravel roofs,โ€ the Built-up roof assembly consists of a base sheet with multiple redundant layers of fiberglass ply sheets mopped solid with hot asphalt. For added flexibility, Modified Bitumen ply sheets can be substituted for the fiberglass sheets.

Roofer walks on built-up roof in San Francisco

Flat Roof Insulation

Roof insulation can be added benath the roof assembly to improve the thermal efficiency of the building and to add sloping to the roof when needed.

Surface Layer

The protective surface layer of a Built-up roofing system can be a layer of aggregate, slag or mineral granules to protect the roof from UV degradation.

Cool Roof

For a smooth surface, a finished layer of a Cool Roof Reflective Coating or a Cool Roof rated white cap sheet provides increased energy efficiency and complies with Californiaโ€™s Title 24 requirements.


GAFGLASยฎ BUR helps to reduce installation costs while tackling the most demanding Built-up roof installations. GAF Ruberoidยฎ membranes offer greater flexibility, impact resistance, strength, and system compatibility as an integral component of a GAF Built-up roofing system.

As a GAF Master Commercial Roofing Contractor our GAF Built-up roof installations qualify for GAFโ€™s strongest warranties, including the Diamond Pledgeโ„ข – No Dollar Limit Roof warranty. 

For Emergency Roof Leak Repair Service

X