Success With Solar Roofing System Starts Long Before Installation

As commercial, industrial and institutional facilities seek ways to reduce expenses in times of rising utility costs, we are seeing a rapid influx of our clients installing photovoltaic (PV) systems installed on their rooftops. One often overlooked issue facing managers relates to the post-installation inspection and maintenance requirements for roofing systems and rooftop PV arrays to ensure both components deliver long-term performance and energy efficiency.

During the design and installation phase for the PV system, many discussions take place related to return on investment and payback. Of course, these long-term, monetary projections include some difficult assumptions. One big assumption is a long service life for the rooftop PV system.

The PV system’s longevity and success implies a long-term successful roof system underneath it. But with the installation of a rooftop PV system, the roofing system becomes more than just a roof. It becomes a permanent platform for the continuous operation, service and maintenance of the PV system that still requires its own ongoing maintenance and repair.

It’s important to consider a number of issues in order to ensure the long-term success of a rooftop PV system. Proper design, quality materials, skillful installation and regular maintenance are four key components to a successful rooftop PV system installation.

The key point we want to discuss in this article is the importance of design to ensure that the roof is compatible with the intended PV system or that it can be upgraded for use with a PV system. For a rooftop PV system, the process of integrated design — having all parties involved with a project, including solar and roofing firms — requires knowledge of both the roofing and PV industries.

At RAMCON, we assist our clients in ensuring that the following design criteria are met.
• Make sure the roofing system will provide at least 25+ years of useful service
• Specify a cover board as a substrate for the roofing membrane in order to prevent damage and to protect the energy-efficiency properties of the roof insulation
• Match the roof membrane’s thickness and proven performance to the required service life of the PV system
• Use construction details that are well established and meet the manufacturer’s requirements
• Elevate framing and conduits above the roof surface to promote drainage, which considerably reduces the potential for leaks
• Design penetrations with round framing so flashing installations are more effectively and efficiently installed, with less chances for voids and need for sealants.
• Install sacrificial membranes or walkway pads at critical traffic locations
• Make sure the rooftop PV system installation does not compromise the roofing system’s warranty, and that you’ll have in your hand an ‘intent to warranty’ from the roofing manufacturer/warranty holder.
• Ensure  that the roofing system’s manufacturer has accepted all PV system details — especially attachments and penetrations — at the design phase.

The goal is to make roofs and solar work together and not have a PV system void the warranty, increase roof maintenance expenses or shorten the roof service life. We work daily, hand in hand with our clients, to ensure they can have the best of both worlds…and at a price that fits into their budget.