Although the appearance of the roof structure was kept simple, the design created several challenges for the roofer.
With a cluster of buildings divided by stairway slots there are many rooftops in a variety of sizes and shapes. They are all flat, which can cause problems with drainage and lead to water pooling. Tackling the problem, the contractor researched a number of products to identify the best material for the job and specified a high-end product with a 25-year warranty.
“We needed a durable, elastic, fully waterproof material,” he says. “We tested it extensively and made sure that everyone, including management, was trained to install the material. Product knowledge and qualified staff are company strengths.”
To address the flat roof, he incorporated insulation to build a gentle slope under the membrane, channeling water off the roof. A computer-generated map laid out the installation plan, with the materials mechanically attached to the roof and heat-welded for a waterproof seal.
The roofing product selected was a single-ply membrane, manufactured by IB Roof Systems, who created the reinforced thermoplastic system nearly 25 years ago. The 6ft sheets of membrane are heat-welded to each other without using adhesives, creating a bond that is stronger than the original material, says Northern California sales representative Will Maddux.
“Because of the waterproof seal, ponding water has no effect and is not an exclusion from our warranty,” he says. “Our EnergyStar® rating recognizes the membrane’s white reflectivity that keeps roof temperatures cool, reducing wear and tear on heating and air conditioning systems.”
The membranes are lightweight at 33lbs to 100sq ft and do not need to be recoated, making them virtually maintenance free. If modifications are required, the membrane can be easily cut and re-welded. The material meets UL Class A code requirements.
IB Roof Systems also supplied the expanding polystyrene insulation, applied in thicknesses of 1/4in to 16in to build up the slope of the roofs.