What is the best type of standing-seam roof for solar panel installations?
I am in the process of redesigning my garage to increase my roof square footage facing south for photovoltaic solar panels. The roof will resemble a “lean-to” and will be 32 feet to the peak and 50 feet long. I plan on using full length sheets to limit seams.
I want the roof to last as I am planning to cover the entire surface. I know the roofing panels will expand and contract with temperature and this can lead to clamps on the standing seam to wear thru the steel.
I found some clamps that spread the clamping surface area to remedy this but by my count I have seen four different types of standing seam roofing sheets. Some have clips over the seam and others are snap lock along with the original crimped seam.
Can anyone steer me in the right metal roofing direction? And does anyone know what this metal expansion will do to my photovoltaic panels?
Thanks,
Eric
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Replies
Eric,
Your choice of a standing-seam metal roof is a good one. This is one of the most durable types of roofing available.
When it comes to differences between seaming methods, your choice is likely to be dictated by what types of roofing are available locally, or what types of roofing are offered by local contractors, rather than any inherent performance differences between different seaming systems. If you are choosing a local contractor, choose one with an established reputation who stands behind his or her work.
Manufacturers of clamping systems for photovoltaic modules have developed systems that tolerate expansion and contraction. If you have any questions about these mounting systems, contact the manufacturer of the clamps or racks. One system I am familiar with is the S-5 system; here is a link to their website: http://www.s-5.com/home/index.cfm
We've had success in the past using clamps similar to the S-5 products, too. How extreme is the weather change where you live? We're based out of Missouri and have to deal with the up-and-down seasons, which is why we have 24-gauge steel within the metal roofing mainframes. It helps limit any instances of contracting and expanding because of the weather. You can see a photo of a garage extension here, and I apologize for the fogginess and distance of the photo.