Rooftop Solar Systems

Solar Roofing

The growth of rooftop solar (or photovoltaic – PV) systems has exploded over the past few years, helped by incentive programs, technological improvements, and the need for alternative energy sources because of rising costs, tight supplies, and environmental concerns. Building owners also have an increased awareness of roofs as an "active asset." Rooftops can be an excellent place to install solar because they are usually unused and unobstructed spaces.

Solar shingles are designed primarily to be used on steep-sloped roofing applications as an electricity-generating replacement for traditional asphalt shingles.

Rooftop solar systems that are designed for commercial buildings with flat roofs can be rack mounted (with ballasted or attached racks) or adhered directly to the roof surface. While an adhered solar system will involve fewer penetrations that require flashing, it also restricts access to much of the roof. A rack-mounted system can allow access to the roof, but very secure flashing methods must be used to avoid compromising roof integrity.

Ballasted rack-mounted systems can allow roof access and have a limited number of penetrations that must be flashed, but wind loads, seismic loads, and weight may be issues.

Utilizing a rooftop to locate PV is not without risks – one of which is the potential to compromise the waterproof barrier that is the roofing system.

Installing solar systems on a flat rooftop requires careful consideration of more than just the efficiency and effectiveness of the system for electricity generation. It also requires consideration of the underlying roof membrane and maintaining its integrity.

The Duro-Last roofing system is particularly effective for rack-mounted rooftop solar systems. It's precision-fabricated to fit each building, and delivered to the job site with up to 85% of membrane seaming completed in our factory. Custom fabricated flashings for roof-penetrating support structures eliminate most rooftop labor from these critical areas. Pre-made rack flashing can mean a faster roofing system installation as well.

Generating electricity through the use of photovoltaic systems is a significant opportunity that is coming of age. Rooftops can be an excellent place to locate solar arrays, especially in locations where open ground may be at a premium. With good planning and design and the use of high quality products with proven installation methods, the rooftop solar system can function in concert with the roof system, providing years of service and benefit from both.