Racking Equipment Guide
Inside this Article
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In this article we survey products available to North American PV integrators for residential or commercial pitchedroof applications. While several of the companies listed here are well-known to veteran installers, others are likely unfamiliar to you. These include established manufacturers in Europe that are relatively new to the US market or are just launching products here for the first time; new products targeted at PV applications from companies that have typically served the broader roofing market; and entirely new product innovations from start-up companies.
Most of the sloped-roof products included here were represented at Solar Power International 2009. While at the event, SolarPro’s team of technical editors were on the lookout for attachment solutions that meet building code requirements for flashed penetrations and for mounting systems designed for installing PV systems on pitched roofs. Here is what we found.
FLASHED OR NONPENETRATING ATTACHMENT SOLUTIONS
Manufacturers, installers and customers increasingly insist on the highest-quality practices for all aspects of the PV installation. It is no longer considered acceptable, for example, to rely exclusively on sealants for waterproofing when lagging an L-foot to a rafter. Many in the industry consider this method negligent, given the flashed attachment options readily available today. After all, the International Building Code requires that all roof penetrations be flashed for proper weatherproofing. Installation manuals from roofing manufacturers and the Asphalt Roofing Manufacturers Association also specify that roof penetrations be flashed. (Refer to the “Wheel of Accountability,” which was developed by Stuart Wentworth at Quick Mount PV, on page 74 of the October/November 2008 issue of SolarPro magazine to see the many sources of guidelines, rules and regulations that pertain to the roof.)
Within the last decade, most racking manufacturers introduced posts—also known as stanchions—as attachment options, which allow contractors to install a boot flashing over roof penetrations. Some installers embraced this method, but others saw it as cost prohibitive. However, when the additional cost of this hardware and the labor to install it is compared with the liability for damage caused by non–code-compliant roof penetrations, many installers conclude that flashing is cheap insurance in the long run. Precisely because the construction industry faces increasing litigation from building owners, especially due to water intrusion, PV installers need to reevaluate their positions about how roof penetrations are waterproofed and how this affects the bottom line.
Historically, this issue of flashing of attachments has been ignored. Installers did not have many alternatives to L-foot attachments. Few inspectors seemed to pay attention to this detail of the installation process. But as jurisdictions formalize the permitting processes that pertain to PV systems, properly flashed roof penetrations will likely show up on the list of their requirements. Fortunately, as the need for and awareness concerning flashed-attachment products have grown, so have the diversity and adaptability of the solutions available to you.
EcoFasten Solar. The latest in a line of companies that offer slate roof services and snow guard systems, EcoFasten Solar is a new entrant to the PV market. Flashed attachments from the company are available for multiple roof types. Its slopedroof product lines include the Quik-Foot and Green-Fasten options, both of which are designed for use on asphalt shingle roofing systems. The Quik-Foot method utilizes a base plate that connects to the rafter using two screws. Flashing covers the base plate, extending below the course of shingles above the attachments. The Green-Fasten method uses a single lag screwed into the roofing member. Flashing is placed under the course of shingles above the lag, and the lag screw passes though the separate block attachment and the flashing as it attaches to the roof member. The installer is not required to cut the roofing shingles while installing either Quik-Foot or Green-Fasten products. In addition to attachments, EcoFasten Solar offers a wide variety of top-compression blocks, including several types of L-feet and Z-feet.
Quick Mount PV. The innovators behind Quick Mount PV have been in the PV installation industry for 7 years and in the construction trades for more than 20. The company offers flashed attachments for a variety of roof materials: composition asphalt, wood shake and flat or curved tile. The products are designed to allow the installer to penetrate the roof surface while maintaining a watertight seal, regardless of the roof material. The composition asphalt and shake products have an aluminum block integrated into the flashing, which allows for connection to any rail system that utilizes L-feet. Rail systems from ProSolar or other channel systems are compatible as well. The tile flashings integrate a post attachment for connection to the rail system. In addition to the PV racking attachments, Quick Mount PV also has products for pool heating collectors and conduit supports for exposed conduit runs.