- Butyl oozing isn’t just a Texas thing—seen it on jobs up in the Carolinas and even a few times in the Midwest, especially on darker roofs. South-facing slopes just cook everything more.
- Honestly, I’ve started moving away from butyl tape for that reason. It’s great at first, but after a couple brutal summers, you get that black goo creeping out and making a mess.
- Had a customer last year with a metal roof where the butyl migrated and actually stained the paint. That was a headache to clean up.
- For solar fan installs or anything that needs a long-term seal, I’m using high-temp flashing tapes or even switching to a quality polyurethane sealant. Holds up better, doesn’t get that gummy texture.
- Heat gun’s handy for reactivating old shingle adhesive, but I’d watch out for making things too soft—especially on those 15+ year-old roofs where the granules are already loose.
- If you’re set on tape, check the temp ratings. Some of the newer stuff claims 200°F+ resistance, but I’m a little skeptical until I’ve seen it after a few seasons.
- Bottom line: nothing’s bulletproof in southern sun, but there are better options than butyl if you want to avoid the ooze.
- Didn’t realize butyl could be such a pain until I saw it melting out of my own roof seams last summer. Looked like someone spilled licorice up there.
- I tried the “high-temp” tape on a vent install—so far, so good, but it’s only been through one Texas summer. Fingers crossed.
- Polyurethane sealant sounds promising, but man, that stuff is sticky. Got it on my hands and it took days to come off.
- Honestly, I thought the hardest part would be cutting the hole, not picking the right goo to keep water out... rookie mistake?
Honestly, I thought the hardest part would be cutting the hole, not picking the right goo to keep water out... rookie mistake?
You’re definitely not alone there. Most folks think the “big moment” is the sawzall, but honestly, it’s the sealing that makes or breaks the job. I’ve seen more leaks from the wrong sealant than from a bad cut, especially once that Texas sun starts baking everything.
Butyl can be a real mess, especially on a south-facing slope. I’ve pulled up vents where it’s just oozed out and collected dirt, looking like someone tried to patch things with black taffy. High-temp tape is a decent option, but I’d keep an eye on it after a couple more summers. The adhesive can start to let go, especially if you get those 100+ degree stretches.
Polyurethane sealant is sticky as heck, no doubt. I keep a bottle of mineral spirits handy just for that reason. It does last, though—if you can get a clean bead and don’t mind fighting with it. Did you use a caulk gun or just squeeze it out by hand? I find a steady hand with a gun helps keep things tidy, but it’s still a pain to clean up.
What kind of roof are you working with? Asphalt shingles, metal, tile? Sometimes the best “goo” depends on what you’re sticking it to. For shingles, I usually go with a good polyurethane or even a high-grade roofing cement if I’m in a pinch. Metal, I’ll use a butyl tape under the flange and then a polyurethane bead around the edge.
One thing I’ve learned: don’t trust the packaging when it says “all-weather” or “lifetime.” The real test is a couple of years of sun and rain. If you’re worried, check the seams after the first big storm or after a hot week. Sometimes you’ll catch a problem before it turns into a ceiling stain.
Cutting the hole is just the start. Keeping water out is the real art. Don’t beat yourself up—everyone’s made a mess with sealant at least once.
I hear you on the Texas sun, but I’ll throw in a different angle—sometimes the “wrong” sealant isn’t really the problem, it’s how it’s applied. I’ve seen folks slap on a ton of goo thinking more is better, but that just makes a mess and doesn’t actually seal any better. Less is more, especially around shingles. I’ve had decent luck with just a thin bead of good old roofing cement, pressed in with a putty knife. Never had it ooze out or collect gunk, even after a few brutal summers. Maybe I’m just lucky, but sometimes simple works best.
I get where you’re coming from about application technique, but I’d push back a bit on relying solely on roofing cement, especially in Texas. That stuff can work for a while, but I’ve seen it get brittle and crack after a couple years of UV exposure. Even a thin bead, if it’s the wrong product for the substrate, can end up letting water sneak in under the shingles—especially after one of those classic Texas hailstorms.
“I’ve had decent luck with just a thin bead of good old roofing cement, pressed in with a putty knife.”
I’ve had better long-term results using a high-quality polyurethane sealant. It stays flexible and actually bonds to both metal and asphalt, which is key around solar fan flashings. Roofing cement’s fine for a quick patch, but if you want to avoid callbacks or future leaks, it’s worth spending a few extra bucks on something rated for both high temps and movement. I learned that the hard way after a couple of “simple” jobs turned into return visits mid-summer. Sometimes the “old ways” work, but the newer products really do hold up better in this heat.
