Reducing floor sound transmission

[shafty85]

So, we bought a house. Long story short, we're renting the main house back to the sellers until their new place is built. We're discovering that the sound transmission between the house and the suite is less than ideal. They have kids and I am fairly certain there is no insulation between the spaces, making the joist cavities lively echo chambers, lulling us into a false sense of craziness with the constant noise of children when we don't even have any of the creatures.

So, what is the best and/or cheapest way to deal with this? While this isn't a long-term situation for us, our hopes are to use this as a rental property in the future and it will hopefully help keep tenants renting longer than if they don't have to constantly listen to the upstairs tenants.

My thoughts are:
1 - remove ceiling drywall, insulate and install some sort of sound transmission barrier on the underside of the joists (rubber? I'm sure there's a product for this). Reinstall drywall. I think is likely the most effective option, but also most likely the most expensive. I'd be able to take all the drywall down no problem, but not keen to put it back up on the ceiling and definitely not taping/mudding/sanding - leave that to people who are good at it, as it will affect the finished product.

2 - I've read online that you can cut a strip out of the drywall and spray insulation into the joist cavities. Seems like a less expensive option, but also less effective and I'm not certain how uniform/good of coverage the insulation would have. Any sort of joist blocking, etc and the spray insulation won't be able to get into all areas of the joist cavity. I'm just not sold that this is a practical option.

3 - Leave it as is - tenants won't care if they listen to our crazy sex parties or the wild ravings of whatever crazy family lives above them if we do move to another house.

What other options are we missing? Anyone dealt with this before?

[ctsmith]

The best (expensive) way would be similar to your #1 proposal using Acoustiblock. It's a membrane like product and the joints get taped. Available directly from the manufacturer, cheesy website, but the product performs very well. Essentially you want to to look at the STC rating of the ceiling / floor assembly. The higher number the better. Insulation and installing the new drywall over resilient channel would be the next less expensive/ effective option.

[BigDaddy]

Easiest and most bang for the buck is to add another layer of Sheetrock to your ceiling and carpet the upstairs floor.

If you have hardwood above you, you want to soften any impacts.


If you elect to go to the next level, make sure you caulk the shit out of any places (joints) where air can get through. Sound will leak like water.

[XXX-er]

I have a downstairs basement suite with 8 ' ceiling s , so the bedroom is right over my bedroom upstairs, so when I rented to a new set of Tennant's i found out buddies gf had done a playboy photo shoot, seemed like agood idea to upgrade the sound proofing.

So i dropped the ceiling 6" using metal t- bar and put in roxal sound deadening and now all I hear is vague muffled sounds from below, I can't tell if buddies trying to get a blow job or getting shit for eating crackers in bed

[Skidog]

Never be the downstairs tennant. I dont think anything short of concrete floors between levels ever does enough.

You can deaden the sound somewhat but youll always hear noisy upstairs tennants.

[XXX-er]

Dammit boy thats the sound of money rain ing down from above but i will give you your mantra which you will repeat when the renter kids rage

Ommm xxx $ a month, xxx $ a month ...

But you wana fix that so renters don't move on ya

[shafty85]

I have a downstairs basement suite with 8 ' ceiling s , so the bedroom is right over my bedroom upstairs, so when I rented to a new set of Tennant's i found out buddies gf had done a playboy photo shoot, seemed like agood idea to upgrade the sound proofing.

So i dropped the ceiling 6" using metal t- bar and put in roxal sound deadening and now all I hear is vague muffled sounds from below, I can't tell if buddies trying to get a blow job or getting shit for eating crackers in bed

That's definitely an option, as I believe we have 8' ceilings as well, but it would mean dropping the ceiling everywhere (in for a penny, in for a pound, as they say) and not sure we want the look of a t-bar ceiling.

The best (expensive) way would be similar to your #1 proposal using Acoustiblock. It's a membrane like product and the joints get taped. Available directly from the manufacturer, cheesy website, but the product performs very well. Essentially you want to to look at the STC rating of the ceiling / floor assembly. The higher number the better. Insulation and installing the new drywall over resilient channel would be the next less expensive/ effective option.

Thanks for the tip on the ceiling. I guess I'll have to start learning about what it is the architects do to figure out the STC ratings.

Easiest and most bang for the buck is to add another layer of Sheetrock to your ceiling and carpet the upstairs floor.

If you have hardwood above you, you want to soften any impacts.


If you elect to go to the next level, make sure you caulk the shit out of any places (joints) where air can get through. Sound will leak like water.

Definitely not putting in carpet and insulation should fill all the air spaces. Would the drywall mud act as caulking in filling air space?

Never be the downstairs tennant. I dont think anything short of concrete floors between levels ever does enough.

You can deaden the sound somewhat but youll always hear noisy upstairs tennants.

Definitely the best option in terms of performance, but not viable to do; the cost would be through the roof with replacing all the flooring, baseboards, doors, etc not to mention the possible need to upgrade the floor joists. Plus, I don't know if the last stair tread would meet code then (additional 1 1/2" inch to step up) and you'd be stepping down another 1 1/2" to the deck. Definitely the best performance option, but not realistic for my situation, unfortunately.

[nickwm21]

There are sound deadening drywall products (quietrock) that are two 1/4" layers of rock laminated with either a sheet of plastic or metal between. The product is mostly used in MD offices, hospitals, lawyer offices, courtrooms, etc to up the STC ratings for confidentiality requirements. You could try hanging the ceiling with that.

Typically sound walls have a layer of quietrock on each side, acoustic insulation inside, all boxes have sound pads, all penetrations have sound-caulk. So as much of that as you can reasonably accomplish will make a difference.

[Skidog]

That's definitely an option, as I believe we have 8' ceilings as well, but it would mean dropping the ceiling everywhere (in for a penny, in for a pound, as they say) and not sure we want the look of a t-bar ceiling.



Thanks for the tip on the ceiling. I guess I'll have to start learning about what it is the architects do to figure out the STC ratings.



Definitely not putting in carpet and insulation should fill all the air spaces. Would the drywall mud act as caulking in filling air space?



Definitely the best option in terms of performance, but not viable to do; the cost would be through the roof with replacing all the flooring, baseboards, doors, etc not to mention the possible need to upgrade the floor joists. Plus, I don't know if the last stair tread would meet code then (additional 1 1/2" inch to step up) and you'd be stepping down another 1 1/2" to the deck. Definitely the best performance option, but not realistic for my situation, unfortunately.

yeah concrete would've been a during construction phase. I dont think retro fit would work here...

do the easiest fix IMHO that deadens at least SOME of the sound and then move upstairs.

[ski-wpk]

Our last house had nothing in between floors. Lots of sound transmission (both upstairs and down). Current house we added insulation in between the joists, RC channel (basically a thin metal grid) between the joists and drywall, and thicker drywall. After all that not much difference in sound transmission. Carpet helps a lot, as I would guess all the other specialized products mentioned above (good to know!).

Just wanted to mention our experience so you don't spend time and effort to insulate, etc. with minimal gain.

[NW_SKIER]

Why not just hit the ceiling with a broomstick when they're being too loud?

In all seriousness, you'll always hear them regardless of what you do.

[::: :::]

Easiest and most bang for the buck is to add another layer of Sheetrock to your ceiling and carpet the upstairs floor.

If you have hardwood above you, you want to soften any impacts.


If you elect to go to the next level, make sure you caulk the shit out of any places (joints) where air can get through. Sound will leak like water.

solid reccomendation ^^^


for an overall strategy to reduce sound transmission, you want to:
A. isolate materials that transmit vibrations, or
B. you want to increase mass, or
C. ideally both

example for A
look into redoing your ceiling with RC channel (resilient channel)
you will have to put sealant along the full perimeter of the ceiling so that you are completely isolating the ceiling from the walls


example for B
multiple layers of sheetrock


example for C
you can also add sound batt to the cavities in the assembly below





Since you likely have multiple floor surfaces on the upper level (tile, carpet, hardwoods), it's more likely that a single side solution will be most economical since you're not necessarily going to replace all those finishes upstairs. If you know that you will update the floor finishes over time, including a resilient mat under those new finishes could be done as a phased project to improve the ratings of the systems indicated above.

Isolating footfalls (like high heels on hardwood) is different than isolating a loud sex, but the tools to make it happen come from the strategies above

read some here:
http://www.greenbuildingadvisor.com/...eep-noise-down
https://www.gypsum.org/technical/usi...s-section-vii/

[abraham]

solid reccomendation ^^^

Do you work on this kind of stuff much?

[::: :::]

Do you work on this kind of stuff much?

i have in the past
in the commercial world more than residential because there are sound transmission standards to hit for multi-unit residential

[Lindahl]

Joists, RSC-1 clips, hat channel, drywall, green glue, drywall - works well for basement home theaters - pretty much the best you can do without fully decoupling the ceiling and floor (new construction). STC is around 40ish I think? Greengluecompany.com will have more info on their site.

[UTpowder]

Joists, RSC-1 clips, hat channel, drywall, green glue, drywall - works well for basement home theaters - pretty much the best you can do without fully decoupling the ceiling and floor (new construction). STC is around 40ish I think? Greengluecompany.com will have more info on their site.

Did something very similar in my office. Nobody living above me but I am an audiologist and remodeled an older home to open my practice. Due to custom dimensions I elected to build my own sound booth. It's worked very well. I do some diagnostic testing for he Army reserves and have to have my booth meet their standards. When it was tested I was told that it did better than many commercially available sound booths.

I'm on a very busy main street location and it can be quite loud. So in addition to the above I had cellulose insulation blown into every where I could find an open space - all exterior and interior walls. High quality windows and heavy doors with good tight fitting rubber thresholds make it very quite inside.

[Gepeto]

Find the most multidisciplinary local insulation contractor over to offer their solutions. Do whatever phases you can/want "DIY" and pay for the rest.

Try this link: http://www.homeadvisor.com/task.Insu...ade.61820.html

Rugs

The most sound proof walls (sound studio) I've ever built were filled with sand to 36" and straight forward in fabrication. Pretty amazing damping effect as a result.

[Alpinord]

A 'parting wall' approach came to mind, initially. Out of curiosity how much better does RC channel work vs simple running 2x2s (or 1x2s) perpendicular to the joists and infill with rigid insulation?

solid reccomendation ^^^


for an overall strategy to reduce sound transmission, you want to:
A. isolate materials that transmit vibrations, or
B. you want to increase mass, or
C. ideally both

example for A
look into redoing your ceiling with RC channel (resilient channel)
you will have to put sealant along the full perimeter of the ceiling so that you are completely isolating the ceiling from the walls


example for B
multiple layers of sheetrock


example for C
you can also add sound batt to the cavities in the assembly below





Since you likely have multiple floor surfaces on the upper level (tile, carpet, hardwoods), it's more likely that a single side solution will be most economical since you're not necessarily going to replace all those finishes upstairs. If you know that you will update the floor finishes over time, including a resilient mat under those new finishes could be done as a phased project to improve the ratings of the systems indicated above.

Isolating footfalls (like high heels on hardwood) is different than isolating a loud sex, but the tools to make it happen come from the strategies above

read some here:
http://www.greenbuildingadvisor.com/...eep-noise-down
https://www.gypsum.org/technical/usi...s-section-vii/

[::: :::]

A 'parting wall' approach came to mind, initially. Out of curiosity how much better does RC channel work vs simple running 2x2s (or 1x2s) perpendicular to the joists and infill with rigid insulation?

the 2x2's continue the rigid frame of the floor/ceiling assembly (so not really solving the issue)
the rigid is just filling volume so you could use something cheaper for that task
probably better to just add layers of drywall

now, if you just glued/screwed drywall thru the rigid (no 2x2 sleeper), you'd be improving the situation, but still not as good as the resilient channel
rc channel >> rigid insul (as isolator) >> hat channel or 2x2

[Lindahl]

Last time I looked, RSC-1 clips work better than RC channel fwiw

[::: :::]

Last time I looked, RSC-1 clips work better than RC channel fwiw

agreed
i'm guessing they're a little more expensive, tho

whatever material is chosen as an isolating device, the important part is to uncouple the vibration path

[XXX-er]

I put FG acoustic tiles in there I should add, dropped t bar was not too expensive, easy enough to do very quickly with a few hand tools , it didn't make a mess and it did cut noise quite a bit, maybe you aren't crazy about it but you won't be down there

[XXX-er]

Heater ducts common to both floors can let a lot of noise thru

[Lindahl]

Heater ducts common to both floors can let a lot of noise thru

Good point. Using insulated flex duct can help, or even sound absorbing insulation lining an MDF custom duct sandwhiched with green glue to go the whole 9.

[RShea]

I would check out more than just pink fiberglass insulation- either blown in spray or the noise batting insulation like in the 2nd example above. Years ago used the sound batting in between the studs in a common wall with noisy machinery and presses and the other side of the the area was office and sales space. While not the same due to being vertical walls, compared to the floors, the pink will probably have very limited total affect.

A skiing acquaintance does some type blown insulation as his business for outside walls and claims there are no gaps with his process and really seals everything up tightly. Many times it is more about the density and material type than thickness of the over all solution.