SpecTips: The Preferred Rooftop Solar Attachment Method

Fully Attached Solar Mounting Solution Included in Watertight Roof Warranty

The use of rooftop solar panels is on the rise as sustainability requirements begin to increase across the United States. States like California and cities like New York City have begun mandating the use of rooftop photovoltaic (PV) systems or other green roofing products on projects meeting certain requirements. PV systems help reduce greenhouse gas emissions and will be critical for those looking to achieve net-zero carbon emissions.

Due to space availability, a building’s rooftop makes an ideal location to install a PV system. The roof allows the panels to be installed in a location that is off the ground, out of the way, and is a smart use of otherwise unused space. However, roof system design, as well as the interaction between the roof and PV racking system, must be considered during the design phase to avoid costly roof damage, allow for routine roof maintenance, and to ensure the roof warranty won’t be jeopardized.

There are two main options for rooftop solar mounting which have been debated over the years – mechanically fastened or ballasted systems. Some building owners and design professionals prefer ballasted racking systems to avoid introducing roof penetrations. Roof penetrations are needed for a mechanically fastened racking system, which can be prone to leaking if improperly installed. However, ballasted PV racking systems cover most of the roof, making inspections and routine roof maintenance difficult, if not impossible. They can also impede drainage, leading to ponding water, which should be avoided. Carlisle recommends mechanically attached PV systems to ensure sufficient space under the panels to allow for inspection and maintenance. When combined with compatible flashings and included in the manufacturer’s watertight warranty, mechanically fastened PV racking systems provide better performance, serviceability, and peace of mind.

Carlisle Construction Materials has partnered with Solar SkyRack to provide a premium solution for PV racking. The Solar SkyRack PV mounting system is fully attached through the roofing system to the roof deck below, providing a more secure and robust attachment for the PV array, Carlisle’s preferred attachment method. Solar SkyRack features fully integrated flashings which are manufactured and warranted by Carlisle when installed by a Carlisle Authorized Applicator.  This removes liability from the building owner and promotes a more maintenance-friendly and secure rooftop PV racking system. Solar SkyRack mounts are available in 5⁰ and 10⁰ tilts and designed for bi-facial PV panels, maximizing efficiency and design flexibility.

SPECTIP
When specifying rooftop photovoltaics, ensure the system used provides access to the roof membrane for inspection and maintenance. For mechanically fastened PV systems, ensure the flashings are included in the manufacturer’s watertight warranty and flashed by a certified and licensed roofing applicator to avoid unwanted liability.

Coordinate with Section 481400 – ‘Solar Energy Electrical Power Generation Equipment’ for the specified types of anchoring necessary for the Solar Panel System. 

For additional information and recommendations, refer to Carlisle’s Solar Ready Roof Brochure.

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