Mounting solar panels: go with traditional flashing or try those newer deck-mounted seals?

- I get where you’re coming from - deck seals do seem cleaner, especially if you’re worried about a bunch of holes in the roof.
- My place is older (asphalt shingles, Midwest), and I went with flashing after seeing a neighbor’s deck-mount leak during a crazy rainstorm. Could’ve just been a bad install, though.
- Honestly, both options have their headaches. Flashing took more time to line up, but I sleep better knowing it’s there.
- Sounds like your setup’s working great, though. Maybe it really does come down to installer skill and local weather.

Honestly, both options have their headaches. Flashing took more time to line up, but I sleep better knowing it’s there.

That’s a pretty common feeling, especially with older roofs. I’ve seen deck-mounted seals work fine on newer builds, but on anything with some age or “character,” flashing just gives that extra peace of mind. The install does take longer - lining up the flashing under the shingles without damaging them can be fiddly, and sometimes you run into brittle or double-layered shingles that complicate things.

One thing I’d add: a lot depends on how well the installer understands your specific roof type. Asphalt shingles in the Midwest can get pretty beat up by freeze/thaw cycles, so any penetrations (flashing or deck seal) are potential weak spots over time. I’ve inspected homes where deck seals looked perfect at install but started leaking after a couple harsh winters.

If you’re dealing with a low slope or older decking, I’d lean toward traditional flashing every time. For steeper, newer roofs, those deck seals might be fine as long as they’re installed right and checked regularly. Either way, installer skill is huge - seen great jobs and horror stories with both methods...

- Had the same debate last year when I put panels on my 90s-era roof (asphalt, Midwest winters).
- Went with flashing - took forever, but I figured better safe than sorry with all the freeze/thaw we get.
- Deck seals looked tempting, but I’ve seen a neighbor’s start leaking after two winters... not fun.
- If your shingles are brittle or double-layered, flashing is a pain, but at least you know it’s solid.
- Installer skill really does make or break it - mine was super patient, which helped a ton.
- If you’re handy and patient, flashing’s doable. If not, maybe deck seals, but keep an eye on them.

I get the “better safe than sorry” angle with flashing, especially in the Midwest where freeze/thaw is brutal. But honestly, I’m not convinced it’s always worth the hassle if your roof isn’t ancient or already leaky. I looked into both options last fall when I had my panels put in (asphalt shingles, about 12 years old, pretty average slope). The installer was all about the new deck seals - said they’ve improved a lot in the last few years, and the install was way less invasive. Less shingle lifting, fewer holes, quicker job. I was skeptical at first, but after seeing how clean the install looked and talking to a couple neighbors who’d gone that route, I decided to try it.

Deck seals looked tempting, but I’ve seen a neighbor’s start leaking after two winters... not fun.

I hear you on that. But from what I gathered poking around online (and bugging my installer), a lot of those early leaks were from cheap seals or rushed installs. The newer ones seem to be holding up better, at least around here. One neighbor had his done with IronRidge seals three winters ago - no issues so far, and we get plenty of ice dams and snow pileup.

I do think installer skill is everything. If someone’s gonna rush it or doesn’t know what they’re doing, flashing probably gives you more margin for error. But with a solid installer who actually follows the manufacturer’s instructions? Deck seals seem fine… at least on roofs that aren’t already falling apart.

That said, if your shingles are brittle or double-layered like you mentioned, I’d probably avoid both options unless you’re ready for some patching. My roof’s still got some life left, so fingers crossed these seals hold up. If they don’t… well, guess I’ll be back here complaining in a couple years.

Curious if anyone’s actually had a deck seal fail recently (like post-2020 versions)? Hard to separate old horror stories from what’s out there now.

I do think installer skill is everything. If someone’s gonna rush it or doesn’t know what they’re doing, flashing probably gives you more margin for error.

Couldn’t agree more - installer makes or breaks it. I’ve seen “leak-proof” deck seals fail in under two years just because the crew cut corners. But honestly, even the best seal can’t save a roof that’s already got issues brewing underneath. Curious - has anyone had insurance push back on claims when deck seals were used instead of flashing? I’ve heard mixed stories, especially after big storms.