"Ended up having to redo the sealing with a different product, which was annoying since the first pass looked perfect at first glance."
Yeah, been there myself. I installed a solar attic fan last summer and ran into similar headaches. Thought I'd done my homework on sealants, but turns out asphalt shingles can be picky. I ended up using a polyurethane-based sealant after the eco-friendly stuff failed to bond properly. It wasn't my first choice environmentally, but it held up way better.
Humidity's definitely sneaky too—had a sunny day that felt perfect, but the sealant stayed tacky way longer than expected. Now I always check the dew point and humidity forecast before starting any roof work. Learned that one the hard way...
Did you notice any difference in attic temps after switching sealants? I'm planning to install one soon, but now you've got me second-guessing my sealant choice. Thought silicone would be fine, but maybe polyurethane's the safer bet. Also, did you have any trouble positioning the fan for optimal sunlight? My roof angle's a bit weird, so I'm wondering if that's gonna be another headache...
I switched from silicone to polyurethane last summer, and honestly, I didn't notice a huge difference in attic temps. Maybe a degree or two cooler at most, but nothing dramatic. Silicone held up fine for me before, but polyurethane just felt sturdier and more durable long-term, especially with the heat and weather swings we get around here.
As for positioning the fan, yeah, that was a bit of a pain. My roof angle isn't exactly standard either, so I ended up using some adjustable brackets to get the right tilt. Took some trial and error to find the sweet spot for sunlight exposure without looking awkward from the street. But once it's set, you won't have to mess with it again, so it's worth spending extra time upfront.
Have you thought about how you're gonna handle wiring or are you going fully solar-powered? I went solar-only to avoid messing with electrical stuff, but now I'm wondering if I should've wired it in for cloudy days...
Yeah, positioning was definitely the trickiest part for me too—spent way longer than I expected fiddling with angles. Did you notice much difference on cloudy days? Mine's solar-only, and honestly, it's been fine even through some gloomy stretches... wouldn't stress too much about wiring it in.
Cloudy days aren't usually a big deal unless you're dealing with several days in a row of heavy cloud cover. I've seen solar attic fans hold up pretty well even during gloomy stretches, just like you mentioned. The bigger issue tends to be debris buildup—leaves, dust, and stuff like that can really cut down efficiency. Have you checked yours after storms or windy periods? I've had to clear mine off more than once after heavy weather rolled through... nothing major, but definitely noticeable if you let it slide too long. Curious if anyone else has had similar experiences with maintenance or if it's just my luck with trees...
