DIY Floor Noise Dampening detail on a Multigenerational 48′ tall ICF home
I am almost done with the shell on my DIY 48′ tall multigenerational ICF home that I have been building after work for the last year and half. Once I get the roof on by the end of the month my attention will turn to putting in the windows and then finally the floor sheathing. I have used open web floor trusses and because this is a multigenerational home that will someday have 4 families living in it, I really want to do everything I can to keep the noise down in-between the 5 floors that make up the house.
I can’t DIY gypcrete so what do you think about the idea of using 1/4″ cork glued to the bottom of the OSB floor sheathing and then screw and glue that to the open web floor trusses. Then 1/4″ of mass loaded vinyl on top of the OSB, then another layer of OSB and then another layer of 1/4″ cork and then finally my flooring. Also in my floor truss cavities I was thinking about putting in fiberglass batts and we are even kicking around putting in a drop ceiling as well.
Does anyone have experience with doing something similar to this?
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I have tried a couple of things and I can tell you what doesn't work. 1/4" cork between OSB won't do much and neither will the MLV.
What does work is concrete over 1/4" cork. This doesn't have to be gypcrete, I've used regular sandmix about 1.5" thick.
For the ceiling bellow, the best is a floating ceiling, that is one that is not attached to the floor structure above at all. The next best thing is hat channel on resilient clips. RC looks OK on paper but doesn't work that well in real life.
As with anything sound, the devil is in the details. The hard part is dealing with all your intersections and eliminating any flanking path and air leaks. This is the real challenge as if you don't get this right, no matter what the STC of your assembly, the end result will not be great. Always test before you close anything up. I find a simple Bluetooth speaker with a smart phone white noise generator works well enough.
No matter what you do, you will never be able to eliminate footfall noise in any light wood framed structure but you can get it so you won't hear anybody or their loud music.
Thank you so much for your thoughtful response! And for sharing your wisdom. I really appreciate it.
LVICF,
To add to the advice Akos gave you - I would start with a rated assembly. That way you can better predict the results. You can find them here:
https://free.bcpublications.ca/civix/document/id/public/bcbc2018/bcbc_2018dbp9rt/search/CIVIX_DOCUMENT_ROOT_STEM:(stc%20ratings)%20AND%20CIVIX_DOCUMENT_ANCESTORS:465649652?4#hit1
This chart is super helpful!!!! Thank you so much for sharing it.
I agree with Akos that the cork, and especially the MLV, isn't likely to do anything here. The MLV will be very expensive too. You'd be better off using homasote board instead. A few layers of type X drywall would give you mass similar to concrete, but would be easier to install I would think (haven't tried this myself).
I absolutely agree that the best ceiling underneath would be decoupled using hat channel or similar. A double layer of type X drywall suspended like this will help damp sounds.
You'll likely be able to cut down significantly on higher pitched frequencies, so you wouldn't hear talking or most music, but it is much more difficult to cut down on low frequencies, such as foot falls and bass tracks from movies. Be careful with your details, air sealing is important for sound too, and I'd avoid putting any holes in that ceiling, so try to avoid any recessed lighting.
Bill
Thanks Bill!! I plan on strapping my ceilings so that I can avoid the penetrations for lights.