Composite tiles themselves don’t seem to trap as much heat as asphalt did, but insulation still helped with overall comfort.
That lines up with what I’ve seen—composite tiles reflect more heat than old-school asphalt, so attic temps aren’t quite as brutal. Blown-in cellulose is great for plugging air leaks and keeping winter drafts down, but in summer, the temp drop inside is usually pretty modest. If you’re after a big cooling effect, attic ventilation and radiant barriers tend to move the needle more. Still, every bit helps... especially when the Midwest humidity kicks in.
If you’re after a big cooling effect, attic ventilation and radiant barriers tend to move the needle more.
I’ve always wondered about radiant barriers—did you install one under your composite tiles, or just rely on insulation? I’m in a similar climate and debating if it’s worth the extra step.
I’ve always wondered about radiant barriers—did you install one under your composite tiles, or just rely on insulation? I’m in a similar climate and debating if it’s worth the extra step.
I actually went through this same debate last summer when we re-roofed. Ended up going with a radiant barrier, but not under the tiles—just stapled up to the rafters inside the attic. The roofer tried to upsell me on a fancy “deck-applied” barrier, but honestly, the price jump was wild and I couldn’t find much real-world data showing it made a huge difference over the attic install.
Here’s what I noticed: before the barrier, our attic would get so hot you could barely stand it by noon. Afterward, it was noticeably cooler—still warm, but not that oven-baked feeling. The AC seemed to run less, though I can’t say it was night-and-day on the bills. We’re talking maybe 5-10% less on average during peak heat. Not nothing, but not a miracle cure either.
Insulation alone helped some, but in my case, adding that reflective layer made more of a dent than just piling on more batts. Still, if your attic is already well-insulated and ventilated, you might not see as much bang for your buck.
Curious—what kind of composite tiles did you go with? Mine are the synthetic slate-look ones (DaVinci), which supposedly reflect more sun than asphalt shingles, but I haven’t seen much difference in attic temps compared to my neighbor’s basic comp roof. Wondering if anyone else has actually measured before/after temps with different tile types?
Also—did you run into any headaches with local code or HOA rules when switching to composite? My inspector nitpicked every little thing...
I’ll push back a bit on the radiant barrier thing—when I did my roof (basic CertainTeed composite, nothing fancy), I skipped the radiant barrier altogether and just beefed up the blown-in insulation. Honestly, I didn’t notice much difference in attic temps compared to my neighbor who paid extra for the rafter barrier install. Maybe it’s our climate (hot but dry), or maybe it’s just diminishing returns once you hit a certain R-value. I’d say if your insulation is already solid, the radiant barrier might not be worth the hassle or cost. My inspector didn’t care about the composite switch, but the HOA had a field day with color matching... that was more of a headache than any code stuff.
I’m with you on the radiant barrier thing—when we moved in, I obsessed over attic temps and ended up just adding more cellulose insulation. Didn’t see any huge difference from neighbors who went all-in on barriers either. Our summers are brutal but dry, so maybe that’s it? The HOA color drama is real though... spent more time arguing about “charcoal gray” than actually picking a shingle.