Metal flashing with a solid bead of sealant is definitely the route I recommend, especially on anything low-slope. Tape just doesn’t seem to have the lifespan, even when it’s labeled UV-resistant. I’ve inspected plenty of roofs where the “permanent” tape started curling up or turning brittle by the second summer, and it’s almost always worse on the south or west sides.
I’ve seen a few liquid-applied flashings in action—some of the newer urethane-based ones seem promising, but prep is everything. If there’s any dust, moisture, or loose granules, you’ll get peeling or bubbling. The other catch is they don’t always expand and contract with the roof as well as advertised, especially after a couple freeze-thaw cycles.
Mechanical fasteners might be old-school, but for anything exposed to high winds (or, honestly, just regular summer storms), they’re still the most reliable. I get the appeal of skipping them for a cleaner look, but I’ve seen too many “easy installs” turn into callbacks when the first big rain hits. If you’re worried about leaks, a little extra work up front with proper flashing and sealant pays off in the long run.
I get where you’re coming from with the old-school flashing and sealant—definitely feels like the “safe bet” on paper. But, for what it’s worth, when I put in my solar attic fan last summer, I actually went with one of those “no-fastener” flashing kits that uses a high-bond butyl tape. I was super nervous about poking more holes in my shingles (our roof is only five years old and I didn’t want to void the warranty). The kit specifically said their tape was UV-resistant and would last as long as the shingles.
I guess time will tell, but after our first winter (with a couple of those wild freeze-thaw cycles and a pretty nasty windstorm), it still looks tight—no curling or brittle edges so far. Maybe it helps that our roof isn’t super low-slope, and the fan is on the north side, so it avoids that relentless afternoon sun. I did go overboard with cleaning the area before sticking anything down… probably spent more time prepping than anything else.
I totally get that tape can be sketchy if you don’t prep well or if it’s in a spot that gets hammered by sun and rain all year. But for folks like me who are really hesitant to mess with fasteners (especially since I’m no pro roofer), these newer tapes might be worth considering—at least on a newer roof in decent shape.
If it does fail, I’ll probably be singing a different tune, but right now, I’m just glad I didn’t have to do any drilling or risk hitting a rafter by mistake. Still, if my roof was older or already had issues, I’d probably agree with you about going with metal flashing all day. Just figured I’d throw out my experience for anyone else who’s nervous about making holes up there...
Man, I hear you on the “no more holes than necessary” front. I’ve seen too many folks end up with a leaky attic after getting a little too drill-happy. That butyl tape stuff has come a long way—honestly, as long as you cleaned the shingles like you’re prepping for surgery (sounds like you did), it’s probably good for a solid run. I’d just keep an eye on it after a big storm or if you get a crazy hot summer. Sometimes those tapes surprise you and hold up better than the old-school goop. If it does start to peel, at least you won’t be cursing a bunch of extra nail holes.
That’s pretty much how I handled mine last summer—minimal holes, lots of patience, and a ton of butyl tape. I will say, I got a little nervous during our first big rain, but it held up fine. One thing I’d add: if you’ve got older shingles, sometimes the tape doesn’t stick as well, especially if there’s any grit left. I ended up using a heat gun on low to help it bond. Not sure if that’s “by the book,” but it worked for me. Just something to keep in mind if you notice any edges lifting after a while.
Interesting about the heat gun—never tried that, but I can see how it’d help with older shingles. Did you notice any long-term issues with the tape after a few months? I’ve had butyl start to ooze in the heat, especially on south-facing slopes. Wondering if that’s just a Texas summer thing or more universal...
