New England Clean Energy has installed 1,000 solar electric systems on homes and businesses in Massachusetts, Rhode Island and New Hampshire, and dozens of those were on metal roofs. That includes standing-seam, corrugated metal, and metal shingles. The process of installing solar on a metal roof is a little different versus the traditional asphalt shingles. Here’s how.
The Difference of Installing Solar on a Metal Roof
Attaching the Rail: Before putting up solar panels, we install a system of rails upon which the panels are mounted. How we do that for metal roofs varies.
Standing-seam metal roofs are great to work on because in many cases, rails are not even necessary. Using special clips, we attach the panels directly to the seams. When the system design and panel layout require rails, the rails are attached to the seams and then the panels to the rails. In both cases, there are no roof penetrations whatsoever, and no screws required.
(Designing a solar energy system for a metal roof also entails a slightly different process, which I’ll write about in a future post.)
With corrugated roofs, the rails are usually attached to the ribs using special hardware which is secured to the rib with two or four screws.
Installing Metal-Shingled Roofing
On metal-shingled roofs, like asphalt-shingled, we use pedestal mounts, which slide up snugly under the shingles. One lag bolt further secures each mount, which we then seal using our Triple-Seal Roof Mount.
Having holes drilled in your roof can strike fear in the heart of a homeowner, but any reputable installer warranties its workmanship, including protection against roof leaks due to the roof penetrations. For example, New England Clean Energy provides 10- and 20-year warranty options.
Attaching the Panels: Once the rail is up, attaching the panels to the rail uses the same method and hardware as for asphalt roofs.
Electrical Work: The electrical work in the basement, outside the house, and on the roof proceed the same for all roofs, regardless of material.
Time Frame: Our crews need twice as much time on a metal roof as on asphalt shingles for two reasons. First, finding the rafters can be time-consuming, as I’ll explain in a future post. And metal roofs are slippery compared to asphalt, which means moving more slowly and more carefully to maintain safety and quality.
Solar on a Metal Roof is a Winning Choice
All in all, installing solar on a metal roof is an energy-efficiency and aesthetic winner. Although our crew members are quick to point out the complexities of installing on metal roofs, they’re also the first to say how tremendous the final product looks.