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Solar Spotlight: K2 Systems on the evolution of solar roof flashings

Tile Roof

In this special edition of Contractors Corner, Johan Alfsen talks about the evolution of solar roof flashings from “goop and a prayer” to tried-and-true metal solutions and new plastic solutions. Below is a is a link to the Solar Spotlight podcast with Solar Power World on Apple Podcast, but it is also available on all podcast applications.

SPW: When you started in this industry, what was the norm for flashings on solar mounting systems?

Johan Alfsen, senior director of product marketing, K2 Systems: I got into it as an installer in 2004 and the norm was an L-foot put straight to the roof and sealant all over it — I call that the “goop and a prayer” era. And then some guys would use a roof flashing over some kind of standoff, but those are the guys that were kind of the innovators who were doing it right.

How has that changed over the years? 

The original owners of Quick Mount PV were installers and they had this product that they started making that was called an all-in-one flashing and mount. So instead of putting in a standoff post and then trying to wedge in a flashing over it, it was a one-piece solution where it was all integrated into one. You slipped it in and bolted it down.

As an installer, I saw this as a huge need and a no-brainer. My classic move was showing up at the job sites with a bag of Gatorades at lunchtime and showing guys this product right out of the back of my truck on a mini roof section. They loved it.

I would say the roofing industry norms and the solar norms were not aligned whatsoever, and now that bridge has been crossed. It was a lot of technical training, a lot of videos and just showing guys how to do it right and trying to keep the efficiency on the roof as well.

What are some situations where non-metal flashings are preferred over traditional metal flashings?

A metal flashing is basically a sheet of metal, typically a 9-by-12 flashing square, with a mount on it and some kind of sealing element. A solar installer has to get a pry bar under there and break that seal and slip the flashing in. It might be easy to do in my area like Northern California where the climate is not too hot and not too cold, but you tell a guy in Las Vegas to pry up 45 or hundreds of shingles, and you can tear that roof up.

So this new wave of what’s been called flexible flashing is a non-metal flashing where instead of prying up the shingles and getting a metal flashing up there, you can now have some kind of bracket that has a sealing element underneath, like a compatible butyl. You peel off the protective paper and essentially glue it down with a tested, proven seal. This is the big debate now, some guys will no way go away from a metal flashing, and that’s fair in certain applications. But like I said, guys in very intense heat can’t get those shingles up, so I totally understand why they want to have these self-sealing products.

You’re going to start seeing more products come out that have these options. We’re looking at it ourselves at K2, but we’re very strict on testing. I’d say it’s regional based, like in Las Vegas or Arizona, where the heat is just so intense that a metal flashing might cause more harm than good.

What should installers prioritize when they are researching the best flashing products to use?

It really depends on where you’re based and what trends you’re seeing with shingles. I would just look at what works best for your install crew. Something that people don’t think about is how you pack things on your belts and in boxes and on your truck. What stacks the best? What works with your flow of work?

Choose what works best for you: Are you doing more new homes, or more re-roofs? Where’s that roof going to be in 10 years and how are you going to be able to pull it off and service it and fix roofs? There’s a lot of options out there, and we’re trying to host more webinars to train on what to look for and what mount to choose because we have options for all the different roof types.

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