I’m curious—has anyone here actually gone with synthetic underlayment and noticed a difference in interior comfort or humidity?
Honestly, I haven’t noticed much of a change in comfort or humidity just from switching to synthetic underlayment. It’s great for durability and water resistance, but I think most of the “comfort” claims are a stretch unless you’re pairing it with solid insulation upgrades. Upgrading to a higher R-value, though—that’s where you’ll feel a real difference. Had a client swap out old batts for spray foam during a roof job, and they said the house was way quieter and held temp better, especially in the attic rooms. The underlayment helps protect everything, but insulation is what really changes the feel inside.
Title: Need Advice On Replacing An Old Leaky Roof
The underlayment helps protect everything, but insulation is what really changes the feel inside.
Couldn’t agree more with this. Synthetic underlayment’s a solid upgrade for durability, but if you’re expecting it to magically make your house cozier, you’re gonna be disappointed. I’ve overseen plenty of roof replacements—unless you’re pairing that underlayment with better insulation or fixing airflow issues, you probably won’t notice much inside. Save the big bucks for insulation if comfort’s your goal. The underlayment’s more like an insurance policy than a comfort upgrade, honestly.
Makes sense about the underlayment not doing much for comfort. I’m curious—if you’re already tearing off the roof, is it worth looking into adding insulation from above, or is that just a waste unless you’re gutting the whole thing? Seems like a missed opportunity otherwise...
is it worth looking into adding insulation from above, or is that just a waste unless you’re gutting the whole thing?
I’d argue it’s not a waste at all—actually, it’s one of the smartest times to do it. A few years back, I managed a project where we added rigid foam above the sheathing during a roof replacement. The difference in thermal performance was noticeable right away, and it barely added to the timeline. Unless you’ve got some weird roof geometry or access issues, it’s almost always more cost-effective than trying to retrofit from below later. If you’re already tearing things off, why not get the most bang for your buck?
I get the logic behind adding insulation from above during a roof job—it’s definitely efficient if you’re already pulling things apart. But I’d just say, from a budget angle, it’s worth running the numbers first. The up-front cost for rigid foam can be a bit of a sticker shock, especially if you’re trying to keep expenses tight. On my last project, I ended up going with blown-in cellulose from below later on because the roofers’ quote for foam was way higher than I expected. If energy bills are killing you or you’re planning to stay put for years, maybe it pays off sooner... but if you’re thinking short-term or resale, it might not pencil out as fast as people say. Just my two cents—sometimes “most bang for your buck” depends on how long you’re sticking around.