Homasote For Soundproofing?
The ceiling in my office and my (soon to be) baby’s room are sagging and in disrepair. I’ve finally decided to take them down, run new electrical, ceiling fan boxes, recessed cans- the works. And no, there’s no detail or molding being destroyed! just flat, saggy, cracked plaster. My plan is to clear out the…
The ceiling in my office and my (soon to be) baby’s room are sagging and in disrepair. I’ve finally decided to take them down, run new electrical, ceiling fan boxes, recessed cans- the works. And no, there’s no detail or molding being destroyed! just flat, saggy, cracked plaster.
My plan is to clear out the plaster and lathe, cut homasote to fit between the joists, then a layer of 1/2″ ply and screw 2x4s against the existing joists to snug the whole thing up against the floor above . Hopefully this will both shore up the sagging and creaky floor in the baby’s room ( no subfoor- just pine planks against the joists) and provide some soundproofing. After that I’ll add a layer of R13 fiberglass or denim insulation and seal the whole thing up with 5/8 rock.
The questions:
A) does that sound like a reasonable plan? I’m hoping the homasote will absorb at least some of the sound that transfers from our home into our neighbors home ( narrow houses with continuous shared joists).
B) Where can I get Homasote around here ( I’m in Clinton Hill but will travel)
Thanks
Homasote is made from recycled newspapers and marketed as a “green” alternative to plywood.
Plywood often contains formaldehyde which is considered a carcinogen. Exterior grade plywood is supposed to off-gas less formaldehyde than interior grade plywood.
Where are you getting the Homasote info that says otherwise?
I’ve had real success with using homosote for soundproofing but my understanding (and other posters all seem to have good ideas) has been that changing the density of the materials is what really works. The other key here is using caulking or fillers at any gaps, like ceiling fixture electrical box etc….You could soundproof all day and leave one gap open that will transmit sound like you hadn’t done a thing.
What I would do is put fiberglass insulation between the joists, then screw 1/2″ plywood to the joists. If the joists aren’t level you can shim appropriately as earlier posters mentioned. Then screw a layer of homosote to the plywood and then a layer of 1/2 sheetrock over that and finish. The great part about using the plywood first is that you can put the screws in the homosote and sheetrock almost anywhere (don’t need to hit the joist) which is great if you are working alone on a ceiling. This combination of material has worked well for me (fiberglass batts+plywood+homosote+rock). You can buy homosote at Home Depot/Lowes or any lumber yard around you house – very common. good luck
the chinese hardware store off tillary by duffield has homasote.
is it really carcinogenic???
if you’re gonna use hat channel, you might also consider going to the next step and using ‘soundclips’ to mount the hat channel. these physically decouple the ceiling from the joists, making it harder for sound to travel. this is what i did to make a band practice room in our basement, it definitely makes a difference. soundproofing.org has the clips. i also used two layers of sheetrock with a layer of sound-dampening ‘glue’ in between. check out ‘green glue’ or quietglue from quietsolutions.com
A professional would not screw the sheetrock directly to the joists. The joists are probably uneven and your ceiling will look it. Run 3/4″ metal hat channels perpendicular to the joists, 16″ on center, shimmed as necessary, and screw your sheetrock into that. You won’t be sorry.
you are doing way too much with very little result.
To acheive soundproofing you want to seperate your materials so sound can not transfer (or even amplify) to the next material.
Insulating with R-13 or higher between joists will help. You may want to secure your squeaky floor from above to the joists to elimate that problem. You then need a dense foam and/or lead barrier between the joists and the sheet rock.
Homasote is carcinogenic. Do NOT put that near your baby!
1) Not sure what you mean, but in general, you should put soundproofing over the joists, not between them, as joists themselves transmit a lot of sound.
2) Home Depot on Dekalb (and norstrand?)