Although a few asphalt shingle roofing manufacturers have a specific presence in solar (CertainTeed has its solar shingles and GAF recently released a decking-attached solar system), most are pretty hands-off when it comes to solar installations. This means solar contractors have to navigate varying roofing suggestions and association guidelines to ensure a solar array is installed correctly and warranties are upheld.
“In an ideal world, a solar installer would reach out to the roofer that put the roof on and give them a head’s up, get any feedback and any info on warranties, [understanding] how what they’re doing will affect the roof,” said Chris Fisher, product manager for CertainTeed Solar. “We recognize that the chance of that happening is very slim.”
If solar installers and roofing contractors/manufacturers aren’t typically talking to one another, where can solar installers seek best installation methods that won’t damage roofs?
First, it’s always recommended that solar installers know what each roofing manufacturer requires for its warranties. They may already require certain flashing or have preferred sealants. They all will also usually refer to national or international codes and standards for best practices.
So, a good first step is to know what type of roof is being installed on and how it reacts with solar panels. The rest is kind of at the installer’s discretion.
Solar Power World reached out to the top asphalt shingle roofing manufacturers in the United States (as determined by the Asphalt Roofing Manufacturers Association) and received mixed messages on solar best practices, so we know what solar installers are dealing with roof to roof. The one thing they did all agree on—be careful working on their roofs. Even if flashing is installed perfectly, sloppy installation methods can cause major damage.
“Damage to a roof that may void the [roofing] warranty applies to not just where you’re putting the flashing, but also to working on the roof, like walking on hot, soft shingles, or balancing modules on their corner and making indentations on shingles,” Fisher said. “There needs to be an awareness to how you’re working on the roof is affecting the roof.”
John Kouba, director of technical services at Malarkey Roofing Products, suggested that certified roofing contractors assess a roof’s health before a solar installer comes in, to ensure the roof can support solar panels.
“It is imperative for solar installers and roofing installers to work together on the installation of a photovoltaic solar system,” Kouba said. “This collaboration can ensure a good solar panel installation that will not damage or shorten the life of the roofing system and reduce the risk of leaks from the solar installation [to] the roof.”
Owens Corning‘s director of products and programs Bert Elliott took this one step further and suggested the roofing contractor be the one to poke holes in the roof, not the solar installer.
“We always recommend that mounting brackets be installed by a reputable roofing contractor,” Elliott said. “They will understand proper roofing practices and water management techniques. Care must be taken to protect the roof from damage during installation, as well as properly following the instructions of the mounting bracket manufacturer.”
Bringing in a roofing contractor might seem excessive, but then there’s no question as to whether roofing warranties are still valid.
Roofing manufacturers might not have obvious lists of dos and don’ts, but a little common sense and extra care paid by solar installers will safeguard them against roofing issues that arise post-installation.
“The last person on the roof is the first person that someone is going to call if there’s an issue,” Fisher said. “Solar installers are going to find themselves in that position where the assumption is that they screwed up the roof.”
If all codes and standards were met, solar installers should have nothing to worry about.