Help Me Save My Tenancy - What Sound Deadener to Use?

Question

To help absorb the carrying costs of financing flip properties, I agreed to remodel an unfinished basement in exchange for a lower-than-market rent for myself. Now that its complete, I see how badly the area under the kitchens tiled floor needs to be insulated from noise. The owner now works a night job, and this has created late-night noise problems as the basement bedroom is directly below the kitchen.

There is a 16" space above the basement ceilings sheetrock that could be filled with fiberglass insulation if a few sheets of rock were removed. Understandably, the owner doesn't favor opening up finished sheetrock if its not necessary.

In looking at Home Depot, I see the R-30 fiberglass insulation (9 inches thick) that could go above the sheetrock if a couple of sheets were removed. I also saw 2" thick polystyrene foam insuation in 4 by 8 sheets that could be attached to the ceiling easily and wouldn't look pretty but might function if its sound deadening qualites are effective.

I also saw 2" thick Tuff-R commercial insulation with an R value of 6.5 that has foil backing on both sides, and Sound Choice Sound Deadener that is about 3/4" thick and looks like a fiberboard.

From a quick and dirty viewpoint, the Polystyrene is white in color and could be attached quickly. This general problem will persist with a future tenant, but the owner doesn't understand the problem so much as he is able to sleep soundly on the upstairs level. I also sleep with earplugs, but guess must be a lighter sleeper.

The R values don't mean so much in a sound deadening situation; What might my best course of action be in this situation? It may come down to both fiberglass insulation and the sound deadener attached to the bedroom ceiling but I don't know the sound qualities of polystrene though it could be attached quickly.

Is polystyrene an effective sound deadener? Maybe I could put it over a layer of the Sound Choice Sound Deadener. Being tired each day is proving tough on making investment decisions.

Burt L. · Answer

A long weekend with my face inside a ceiling; the floor joists are 2 X 16, on 24" centers. The contortioning was from working between joists two rows over from the ceiling opening - at times - to keep cuts into the finished ceiling to a minimum. I haven't yet applied drywall compound to the seams where the openings have been re-sheetrocked, but much of what was predicted seems to have borne out. I do hear much less of the low frequency noise above, such as dogs eating dog chow etc. but there doesn't seem to be much difference in the sound of footsteps or dogsteps. I knew it was chancy, but had little to lose by trying as resigning the ceiling struture of a room I inhabit is a difficult stretch now. On to the next step - so to speak. thanks for the help.

Jon Holdman · Answer

I had assumed when you said there was 16" space that there were 2x16 floor joists. From your description of contorting to get insulation in other spaces, it must be something different.

Burt L. · Answer

I was able to start installing insulation in the ceiling today, by cutting some 4' by 4' openings. I found that I can work two floor joists over from the openings, with some serious contortioning. With 16" of height to work with, I went with R-30, which is 10.5" inches tall. Even lucked into some 24" wide batts at Lowes. Hope to make some progress in the sound deadening; there are other things I may have preferred to do this weekend besides manuver insulation into place by cutting into a finished ceiling, but this is important. Thanks for the suggestions

Aaron McGinnis · Answer

Something to do for dust contamination... buy a lot of sil (Maybe 2mm or so) and turn the area into a giant plastic bag. You'll spend easily $50 on Sil, but it will make cleanup very easy. You won't find batt insulation for 24" centers. Get regular batts and cut them length-wise to fit... if you have 16" joists (That's a giant joist. Sounds like an LVL beam or something) you may be able to stack more than just R-30 in there. Basically, the more insulation you can cram into the space, the more the sound will be deadened.

Burt L. · Answer

I appreciate the replies and the additional research done in distinguishing between low and high frequency noise. My primary issue is the low frequency found of footsteps on a tiled kitchen floor above. Due to the direction the joists run, it would be relatively simple to remove just two sheets of sheetrock that run lenth of the room, in the center of the room, and slide in R-19 that is 9 inches tall into the space thats 16" above the sheetrock. I realize I'm addressing the wrong frequency, but then I can "work from the top down" by addind sound-proofing below it, if its proves unsuccessful by itself. I'll try to locate some R-19 for 24" centers tomorrow morning as the local Home depot didn't have it on the shelf. As I'm living in the unit, refinishing an entire ceiling and living in the dust again isn't so appealing, a second time. I could then add the sound prrofing below, which would be ugly, but the owner avoids major expense and I avoid dust around computers, and having to sell the owner on another major remodel. Maybe the combination will be successful. I'd use sound -reducing earmuffs over my earplugs if I could sleep on a pillow with earmuffs, but I"ve already tried that. Thanks for the insight.

Jon Holdman · Answer

I did some more research on the topic after Burt posted. The consensus is putting some insulation between the joists will help with high frequencies - voices. The low frequencies - footsteps - are transmitted through the joists. Ideally, you would have both. In my basement, which has nothing between the joists, but does have the resilient metal strips, footstep noise is the issue. At one time we used this room for our bedroom, and I had a hard time to sleeping because of footsteps. Adding another layer of sheetrock was a pretty frequent suggestion, but Burt seems to be saying modifying the ceiling isn't really an option. If the headroom exists, adding a drop ceiling with insulation above it should help significantly.

Aaron McGinnis · Answer

I'm going to disagree with Jon here, and say that putting batts in the ceiling would have a positive effect on sound dampening. We've used batts in that way to deaden sound from bathrooms and laundry rooms adjacent to living areas with good effect... even R13 would make a difference. Lowes sells sound insulating sheetrock that would help as well. Sound can also travel through the walls, so having insulated wall cavities would make a difference. On the very expensive end of things, consider using foam insulation (icynene, sp)... it'd cost a fortune, but that'd be as good as you're gonna get for sound dampening effect (It'd also make the space such that you could heat it with a birthday candle and cool it with an ice cube, but that's another story entirely.) A thought for further research would be to look this topic up on websites geared for musicians. I know a few drummers who had excellent tactics for soundproofing their practice rooms. This can get as expensive and complicated as using a sound-baffling matrix material (looks like egg cartons) in the walls and ceiling to reduce noise.

Burt L. · Answer

Thanks for the reply - yes, the sheetrock is attached directly to the floor joists. It sounds as though even if there had been fiberglass insulation placed in the 16" tall space between the sheetrock and the tiled kitchen floor, it would have made little to no difference. The floor joists are on 24" centers. Short of removing a finished ceiling, buidling a new joist system and refinishing the ceiling again - it seems that I"ve little to lose by getting sheets of sound deadener and attaching it to the ceiling to see if it makes a difference. I can add a layer of the polystyrene below that, next. I don't know what any health effects might be of sleeping below polystyrene. It also seems this has little to do with "R" value. I learned to sleep with ear plugs some years ago during my dormitory years, and haven't slept without them since. Some people think that makes me a little odd, but sleep is more important. Maybe I can find some thicker sound deadener besides that offered at Home Depot at $10 per sheet. I will need eight sheets. Great to know that opening the ceiling just to install fiberglass insulation - would likely have been a waste of time and resources. That would have been very frustrating. Think I'll try adding sound deadener to the ceiling before redesigning the floor joists as this stage of testing will be so easy. A subsequent tenant will have the same problem, and I"m open to other suggestions too.

Jon Holdman · Answer

Is the basement ceiling sheetrock nailed directly to the floor joists? If so, that's you sound source. Vibrations from the floor transmit through the joists to the ceiling sheetrock. Adding something into the spaces between the joists won't help much, if at all. You need to decouple the ceiling sheetrock from the joists. I've sheet metal strips that attach to the joists and then you attach the sheetrock to those. We have those in part of our basement. Not very effective. Best would be to rip out the ceiling, install a totally separate set of joists between and not touching the existing ones and hang the sheetrock from those. Put the sound deadening material between the two sets of joists, zigzagging between them. The new joists only have to support the sheetrock, not a load from above, so relatively small boards, maybe even 2x4's would work. I'm skeptical putting an inch or two of anything directly onto the ceiling would work. Perhaps a drop ceiling with something on top of it. Have you considered ear plugs? Totally serious.