Why solar panels and steel roofs form a long-lasting partnership
Pairing a ‘PV’ array with a steel roof delivers long term financial and durability benefits
November 30, 2016 by John Bleasby
As more Canadians choose to add an array of solar photovoltaics (or ‘PV’s’ in today’s lexicon) to their roof tops, simultaneous consideration needs to be given to the type of roof material serves as the base platform. In fact, while clients might be drawn to the long term financial benefits of solar energy for their homes, they might be overlooking the importance of the platform underneath delivering parallel long term performance too.
Matching the life of the roof material to the life of the solar panel
It’s not a matter of simply installing an array of PV’s on an existing shingled roof; that could be a serious error. Why? Solar panels have a life expectancy of 30 to 35 years. What would be the point of installing an expensive array of PV’s on a roof that might require replacement or repair in only 15 to 20 years, even less? That would mean disconnecting and removing the panels in order to service or replace the roof membrane or tiles, storing those components safely, and then reassembling the system back on the new roof. Costs could run into the thousands, more if any panels were damaged in the process. Of course, while the argument can be made that protection from UV and weather elements offered by the panels can increase a standard roof’s life, it is a gamble likely to be lost. That’s why more and more engineers and designers are recommending steel roofs instead.
Steel roofs deliver long term value
Many steel roofs offer warranties as long as 45 years. Even without the distraction of a solar array brought into the equation, the industry has long argued that steel roofs deliver the best long-term value despite slightly higher upfront costs. In many cases, a steel roof can be a positive sales feature when the original owner moves on. This is on top of the fact that the steel is fully recyclable at the end of its long useful life, unlike asphalt shingles which usually end up in the landfill, which somewhat negates the environmental gains by installing solar in the first place.
And while talking about the protection from the sun’s rays that a solar array gives, that can sometimes backfire on a traditional tiled roof in warm, humid conditions. That heat and humidity under the panels can promote fungus growth, something steel roofs discourage because of the zinc in the coatings.
Steel roofs are perfect for clamp-on mounting brackets
And then there is the mounting of the solar array brackets themselves. The popular standing-seam metal roof is an ideal host for the brackets that are available on the market. These brackets clamp on to the roof rather than penetrate the surface, thus maintaining warranties and eliminating leaks.
One can always make subjective arguments concerning the style and appearance of a steel roof, and no one will win. Aside from that, many solar arrays installations are on the highest roof tops of a multi-roofed home, often out of sight from the street or garden. Given the long term value expected by homeowners in terms of durability and financial savings, solar and steel should be considered a matched pair in any new-build or renovation situation.
follow John on Twitter @john_bleasby