I hear you on the basics. I got sucked into the hype and paid extra for a “lifetime” underlayment last time I reroofed. Honestly, it’s still the attic insulation that made the biggest difference in comfort. Fancy stuff’s nice, but not magic.
That’s a pretty common story, honestly. There’s so much marketing around “lifetime” underlayments and all these high-tech materials, but the basics like solid attic insulation or even proper ventilation usually make the biggest difference in real-world comfort and energy bills. I’ve seen a lot of folks invest in premium underlayment expecting it to solve leaks or keep the house cooler, but if the rest of the system isn’t up to par—especially in older homes—it doesn’t move the needle much.
Not to say there’s no value in better underlayment. If you’re in a region with wild temperature swings, ice dams, or heavy storms, the extra durability can help prevent water intrusion when shingles blow off or during wind-driven rain. I’ve been on roofs after big storms where the only thing keeping water out was a solid synthetic underlayment. But if leaks aren’t your main concern, and you’re after comfort or energy savings, insulation and air sealing usually give you more bang for your buck.
I get why people go for the “lifetime” stuff, though—peace of mind counts for something, especially if you don’t want to think about your roof again for decades. But yeah, there’s a limit to what any one product can do on its own. Sometimes it’s just about balancing priorities—spend where it matters most for your house and climate.
Curious—what kind of attic insulation did you end up using? I’ve seen people get surprising results just by topping up old fiberglass batts or blowing in cellulose. It’s not flashy, but it works.
- Gotta agree, underlayment is only one piece of the puzzle. I’ve seen folks drop $$$ on “lifetime” synthetics and still have ice dams because their attic’s a sauna.
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100%. We topped up with cellulose in my parents’ place—suddenly the upstairs wasn’t an oven.“I’ve seen people get surprising results just by topping up old fiberglass batts or blowing in cellulose. It’s not flashy, but it works.”
- Not knocking premium underlayment, though. After last year’s windstorm, the only thing between us and a waterfall in the living room was the synthetic stuff. Worth it for that peace of mind, but yeah, insulation and air sealing did way more for our bills.
- Curious if anyone’s tried spray foam? I hear it’s great but $$$.
- Seen spray foam used a few times, but honestly, it’s not a silver bullet.
- Pros: air seals like nothing else, great for weird angles and gaps.
- Cons: pricey, and if it’s not installed right, you can end up with moisture trapped in the wrong spots. That’s when rot or mold creeps in.
- Had a client with cathedral ceilings—spray foam fixed their ice dam issues, but their HVAC guy struggled to run new lines after. Stuff’s hard as a rock once it sets.
- Cellulose is messy but forgiving. If you get a roof leak, it dries out easier than foam.
- Underlayment’s saved me from leaks more than once, but I still see folks skipping attic ventilation and then wondering why their roof’s cooked after ten years.
Curious—has anyone actually had spray foam *cause* problems down the line? I’ve seen mixed results, especially in older homes where air flow isn’t great...
Curious—has anyone actually had spray foam *cause* problems down the line? I’ve seen mixed results, especially in older homes where air flow isn’t great...
You’re spot on about spray foam not being a cure-all. I’ve seen it do wonders for energy bills, but yeah, in older houses with weird airflow, it can backfire. Had a neighbor who went all-in with closed cell foam in his 1950s ranch. The installer skipped a vapor barrier and didn’t address some old soffit vents. A year later, he found mold creeping along the rafters—turns out moisture was getting trapped with nowhere to go.
I’m with you on underlayment being a lifesaver. If you’re dealing with an older roof, here’s what’s worked for me:
1. Make sure attic ventilation is solid before adding any insulation (especially foam).
2. Use a high-quality synthetic underlayment—it’s held up way better than felt for me, especially after a couple nasty hailstorms.
3. If you’re set on spray foam, double-check that your installer knows how to handle older homes and doesn’t just seal everything up tight without thinking about moisture movement.
It’s all about balance—air sealing is great, but not at the expense of letting your roof “breathe.”
