How I put in a solar attic fan (and what I’d do differently next time)

That rafter spacing thing is always a treat, right? I swear, every time I open up an attic, it’s like a box of chocolates - never know what you’re gonna get. Scrap 2x6s are basically the duct tape of framing in my book. Not pretty, but if it holds and you’re not planning to host a tea party up there, who cares?

On the flashing, I hear you about peel-and-stick. It’s quick, and I’ve seen folks use it for all sorts of stuff, but in central Texas? That sun will cook anything that isn’t metal or stone. I’ve seen more than a few “miracle” tapes just curl up and wave goodbye after a couple summers. Metal’s a pain - especially if you’re up there with tin snips trying not to slice your hand open - but at least you can sleep at night when the next thunderstorm rolls through.

Ever notice how some of those solar fan kits come with the flimsiest flashing known to man? Like, did they expect us to install this on a dollhouse? I usually end up tossing their hardware and using something beefier from the local supply store. And don’t get me started on the screws they include - half the time they’re made of cheese.

One thing I’ve started doing is running a bead of high-quality sealant under the flashing lip before screwing it down. Not textbook, maybe, but it seems to help with those weird roof pitches and old shingles that don’t sit flat anymore. Anyone else run into issues with shingle granules getting under the flashing and causing leaks? Or is that just my luck?

Anyway, I’d take ugly-but-solid over pretty-and-leaky any day. At least until someone invents self-installing fans that actually fit where they’re supposed to...

- Totally agree about the “cheese screws” - I’ve had a few snap off halfway in, which is always fun to dig out.
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“running a bead of high-quality sealant under the flashing lip before screwing it down”

- I do the same, especially on older roofs where nothing sits flush anymore. Never had an inspector complain.
- Granules under the flashing? Yep, especially after cutting shingles for the opening. I usually brush the area clean, but sometimes you just can’t get them all. Noticed it’s worse with the thicker architectural shingles.
- Curious - has anyone tried using butyl tape under the flashing instead of just caulk? Wondering if it’d hold up better in the heat or just make a mess.

Tried butyl tape on a vent install last summer - honestly, it got super gooey in the heat here (central Texas). Was a pain if I had to reposition anything. I’d stick with a good sealant unless you’re somewhere cooler or less humid.

Had the same issue with butyl tape on a skylight install here in Austin. It turned into a sticky mess by midday, and I ended up with fingerprints everywhere. Switched to a polyurethane sealant for the next one - way less hassle, even if cleanup’s a pain. Curious if anyone’s had luck with those high-temp tapes?

Curious if anyone’s had luck with those high-temp tapes?

Butyl tape just doesn’t cut it in Texas heat - it’s like trying to work with half-melted chewing gum. I get the appeal of polyurethane, but man, that stuff is expensive and a bear to clean up. I’ve seen some folks swear by the foil-backed high-temp tapes for metal roofs, but I’m skeptical about long-term adhesion once the sun starts baking everything. Has anyone actually had one hold up through a full summer without peeling or leaking? I’m not sold on paying double unless it really lasts.