One of the the top three concerns of homeowners considering a solar PV installation is whether the solar PV panels will cause the roof to leak, according to the solar advocacy and education website, SolarPowerRocks.com. After all, common sense implies that, if a solar installer is drilling holes in your roof, there is more of a chance for leaks in the future. This could be true, except when you consider the method a reputable solar installer uses to attach your solar PV array and the sealing materials he uses around those holes.
Solar Panels Are Mounted to the Beams, Not Roofing Shingles
Ask prospective solar installers exactly how solar panels are mounted to the roof. In most cases, they drill through the roof with a heavy duty bolt, in order to attach the solar panels directly to the rafters.
Solar panels should be mounted at a 20 to 30 degree angle (this varies based on the pitch of your roof, the direction your roof faces, even where you live — and one of those things a solar installer will know best!). The biggest danger with solar panels is that wind will get beneath them and they will fly off, taking roofing shingles with them. If the solar panels are mounted directly to your rafters, there is no danger of this. (If winds could ever be heavy enough to literally pull the beams from your home, you have much bigger problems than a leaky roof!)
Solar Panels Should be Well-Sealed
Most reputable solar installers — like any contractors — want to do a good job for their customers. Business is driven by word-of-mouth referrals, especially in a growing industry like solar power. Your solar installer should use some of the best sealant around to ensure against leaks at the points-of-attachment. Check with past customers and the Better Business Bureau, and shop for your solar installer through a reputable resource like EcoOutfitters.net.
Solar Panels Melt Snow Faster
Often, roofs leak in cold climates because of massive snowfall, not rain. Snow piled up on rooftops eventually melts and, if it melts faster than the ice forming below it, can cause ice dams and lead to leaking in the home. (This happened to friends of mine in the Midwest.) Additionally, snow on a roof with no pitch or a low pitch can get heavy and literally cause the roof to cave in. (This threatens to happen to friends of mine in Maine every year!)
Solar panels can alleviate these problems because the solar panels heat up quickly and melt the snow. No snow, no ice dams, no roof cave-ins. Solar panels, constructed from super-strong silicone and other composite materials, are not likely to collapse due to the weight of the snow.
We’re not going to say that solar panels are less likely to leak than an actual new roof in good condition, but think about it: If your solar panels are securely attached to wood or metal rafters below your roofing shingles, even in high winds they’re not going anywhere. Can you say the same for your roofing shingles during the next hurricane or tornado?