I've noticed similar results with fiberglass myself. Did my attic a few years back and while it definitely helped with heat, I still hear every raindrop during storms. Funny you mention carpet remnants—I actually tried something similar but with old moving blankets. Tossed them up there as a temporary fix, and weirdly enough, it did make a noticeable difference in noise reduction. Not exactly a long-term solution, though... dust magnets for sure.
As far as cellulose goes, my brother-in-law had it installed professionally about three years ago. He loved the soundproofing at first, but yeah, the settling issue became pretty obvious after the first winter. He ended up topping it off again himself last summer—said it wasn't difficult, just messy and time-consuming.
Honestly, I'm leaning toward spray foam if I ever redo mine completely. Pricey upfront, but from what I've read and heard from others who've done it, the sound dampening and insulation values seem worth considering. Just gotta convince myself (and my wallet) to pull the trigger one of these days...
Spray foam definitely has its perks, especially when it comes to sealing air leaks and boosting energy efficiency. But from experience, the sound dampening might not be as impressive as you'd expect, especially for rain noise. Had a client who went full spray foam last year—he loved the insulation factor and lower energy bills, but during heavy rains, he still noticed quite a bit of drumming on the roof. Turns out spray foam's great at blocking airflow and thermal transfer, but it doesn't necessarily absorb vibrations well.
If noise is your main annoyance, you might want to consider pairing spray foam with something specifically designed for acoustics. I've seen people add mass-loaded vinyl or acoustic panels underneath the roof decking before foaming. A bit more work (and money), but it can really help quiet things down.
Just something to keep in mind before you commit to the expense of spray foam alone...
Good points overall, but honestly, I've seen spray foam do a decent job with noise reduction—depends a lot on the roof material and thickness of the foam. Had a homeowner last spring who switched from fiberglass batts to closed-cell foam, and he swore the rain noise was noticeably quieter afterward. Not saying it's perfect, but maybe your client's roof decking or shingles were part of the issue too? Just something else to consider...
I've noticed something similar on a few inspections, actually. Closed-cell foam can help with noise, but I've also seen it amplify certain sounds if the decking or shingles are thin or installed poorly. Had one homeowner who was convinced foam made his attic louder, turns out his roof decking was wafer-thin plywood from the '80s. Once he upgraded the decking, things quieted down nicely. So yeah, foam helps, but it's definitely not the whole story—gotta look at the whole roof assembly sometimes...
Had a similar experience on a job last summer. Homeowner had us spray closed-cell foam thinking it'd solve all his attic noise issues. At first, he swore it got louder, especially during heavy rain. We went back up to check things out, and sure enough, the decking was super thin OSB that had warped over time. The foam was basically turning the whole roof into a drum skin, amplifying every drop of rain.
Ended up pulling off the shingles, replacing the decking with thicker plywood, and reinstalling everything properly. After that, the foam actually did its job—temps dropped noticeably, and the noise was way better. Learned a good lesson there: foam insulation is great, but it won't fix underlying structural issues. Always worth checking the decking and overall roof assembly before jumping straight to insulation upgrades...
