Aluminum and other metallic solar flashing requires installers to pry composite shingles up to slide the sealing roof attachment beneath. Depending on the condition of the roof covering, shingles can break in the prying process, leaving installers responsible for sourcing and replacing them.
Back in 2012, solar roof mount manufacturer QuickBOLT (SolarRoofHook at the time) released a lag bolt-driven roof attachment by the same name with a rubber puck accessory dubbed Microflashing. The QuickBOLT product didn’t require a mechanical flashing — instead, it went straight through the shingle into the rafter. It uses roof sealant, Microflashing and the force from the driven lag to create a waterproof seal.
At the same time, EJOT carried a lag bolt mount with a smaller washer, and Zep Solar offered an over-the-shingle mount that was acquired by SolarCity (and has been seen on recent Tesla installs). Jared Wiener, executive VP of QuickBOLT, said that it took until 2016 for Microflashing to catch on, and now the company has sold over 2 million units.
Since then, several other manufacturers have released similar mounting solutions with smaller overall footprints that are flashing-free, use a chemical flashing or have minimal flashing when compared to the typical aluminum under-shingle solution.
“That to me is fantastic. It’s a testament to the quality of the technology,” Wiener said.
Each of these over-the-shingle roof mount options have different individual components but require similar steps for installation. In most cases, it takes finding the rafter, drilling a pilot hole through the shingle, filling it with sealant and driving the lag bolt through. The shared attribute is no shingle-prying required.
The mounting manufacturers with over-the-shingle roof mounts consulted for this story and their relevant products are as follows:
- Unirac released FLASHLOC COMP in 2019, which is a two piece system — the mount and the lag bolt/washer. The installer fills a reservoir in the attachment with sealant after the lag bolt is driven until it expels from two vents, further sealing the penetration with a “chemical flashing.”
- Roof-Tech’s RT-MINI, RT-Apex and RT-AIR use a butyl tape on the roof-facing surface to “self-flash.” Each model is designed with four potential mounting points that can be used in both decking (four screws) and rafters (two screws). These mounts use stainless steel woodscrews as opposed to lag bolts.
- SunModo released a flashing-free over-the-shingle mount called NanoMount this spring that comes in both rafter and decking models. The rafter NanoMount requires one lag bolt, while the decking model uses up to four. The bottom of the attachment has a silicon gasket that self-seals as the lag passes through it, requiring no pilot holes.
- SnapNrack just brought its SpeedSeal Track and Foot to the market in October. SpeedSeal Foot is compatible with the company’s Ultra Rail Roof Mount series and the Track with the RL-U Roof Mount. SpeedSeal has an EPDM compressible ring that is filled with sealant through a pilot hole. When driven, it creates a seal.
- And QuickBOLT, whose Microflashing set the course. The company is soon releasing Deck Mount, a T-foot over-the-shingle mount with four lag screw points and a silicon adhesive bottom for comp shingle decking attachment.
Each product has run the gamut of waterproofing and wind and weatherization testing, but aluminum or mechanical flashing remains a common practice in solar roof mounts.
“In most places, it’s been accepted by AHJs, but there are still hang ups,” said Connor Morrison, product manager for Unirac, about minimal flashing products. “Naturally, that’s an old school way of thinking.”
Designed with installer in mind
These minimal roof mounts with smaller overall footprints match the necessary number of attachments to hold a rooftop solar array as those using mechanical flashing. And every component required to install them can often fit in one box, meaning fewer trips down the ladder for installers.
John Ferreira, training analyst in operations training for Sunrun, has been installing solar since 2012. He found that in colder conditions, the sealant used with mechanical flashing would often freeze. The company recently started working with SnapNrack’s SpeedSeal and other over-the-shingle mounts and found that sealant freezing wasn’t an issue given the speed to install.
The fewer materials in over-the-shingle roof mounts can also mean less investment for installers, and many come with 25-year warranties.
“I do believe it’s important to note that all we’re trying to do here is help the solar industry,” QuickBOLT’s Wiener said. “Our job is making solar more affordable, and I personally want to see the solar industry grow in the United States. In a way, that allows people to get over the biggest hurdle.”
Special installation considerations
When using these Microflashing-style mounts, installers should take extra care to find the rafter. One advantage of mechanical flashing is a larger surface area and more room for error with mis-drilled pilot holes.
Another concern is the materials used in certain products can be incompatible with composition shingles. EPDM rubber is chemically incompatible with asphalt, a major ingredient in comp shingle rooftops.
These products can come with a sealant solution included in the mounting kit, but in case they don’t, it’s recommended to look for one that can work on multiple substrates and climates; and that the sealant has a history of prior roofing applications.
Despite the few extra considerations, minimal-flashing options can help installers do their jobs quicker and lessen the possibility of damage to shingles during installation.
“I think that the mechanical- or flashing-less installations are the way of the future,” SunRun’s Ferreira said. “I would be upset if I was an installer and had to go back to mechanical flashing, that’s for sure.”