Had the same problem with the old felt on my place—looked fine from the outside, but when I pulled up a few tiles, it was like peeling apart wet cardboard. I switched to synthetic underlayment last year when I replaced a section, and honestly, it feels way sturdier. It was pricier, but it didn’t wrinkle or tear when I walked on it, and it’s supposed to last longer. Still, I’m not convinced it’s a miracle fix for damp climates... water finds a way if there’s a weak spot. I’d pick underlayment over just sealant any day, though. Sealant alone just seems like a band-aid.
Yeah, sealant’s kind of like putting a sticker over a leaky pipe—might help for a bit, but you’re asking for trouble down the line. I’ve seen synthetic underlayment hold up way better than old felt, but you’re right, nothing’s totally waterproof if there’s a gap or crack. In my area (lots of wind-driven rain), the folks who skip proper underlayment always end up with soggy attics. At least the synthetic stuff buys you some time when tiles inevitably shift.
- Just bought my first place last year, and the inspector pointed out the old felt underlayment was basically toast.
- Had a few cracked tiles, but the real issue was water getting in through tiny gaps—sealant patches didn’t do much except make a mess.
- Ended up replacing the whole underlayment with synthetic (cost me more than I wanted, but whatever).
- We had a crazy storm last month—wind and sideways rain. Tiles shifted a bit, but attic stayed dry for once.
- Honestly, sealant feels like a band-aid. Maybe okay for a quick fix, but I wouldn’t trust it long-term.
- Synthetic underlayment seems to buy you time if something goes wrong up top. Not perfect, but way better than what I had before.
- If I’d just kept slapping on sealant, I’d probably be dealing with mold by now...
I get what you mean about sealant being a band-aid. I tried patching a couple of spots on my tile roof last fall—looked fine for a few weeks, but after the first heavy rain, water still found a way in. Ended up with some damp insulation and a musty smell in the attic.
Sealant patches didn’t do much except make a mess.
That’s exactly what happened here. I’m debating whether to bite the bullet and do the synthetic underlayment too. Did you notice a big difference in cost between felt and synthetic? I’m trying to keep things affordable, but I also don’t want to keep paying for quick fixes that don’t last.
I hear you on the sealant mess—I've seen more than a few jobs where folks tried to save a buck with patches, and it just led to more headaches down the road. Synthetic underlayment’s definitely pricier up front than felt, but in my experience, it holds up way better, especially under tile. I did a job last year where the homeowner went with felt to save money, and we were back two years later redoing it after another leak. Sometimes spending a bit more now saves you from doing the same work twice... or three times.