Alternatives to mass-loaded vinyl?
Aedi
| Posted in General Questions on
Hi all,
I know the green building community is not overly keen on PVC (for good reason), and I certainly do not want to put it inside my building envelope if I can help it. Unfortunately, one of the more useful sound dampening materials is mass-loaded vinyl, or MLV. Does anyone have any alternatives to MLV for cheaply adding weight underneath flooring for sound dampening purposes? All I can seem to think of is concrete or gypcrete, or perhaps some generic rubber sheets.
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Serena Mat: https://www.soundproofingcompany.com/product_information/serena-mat-underlay
Made from 93% recycled "crumb rubber".
Looks like a solid product. The extra elasticity will help with impact noise, though unfortunately it is less than half the density of MLV, making it less efficient for adding mass.
Aedi,
What is your floor structure, are you trying to prevent air borne noise or foot fall noise from going through? Generally MLV is a waste of money except in very specific circumstances.
Preventing air borne noise from the room below. I'll be implementing a few different soundproofing strategies in the whole assembly, but the in this case the MLV is just for adding mass without raising the floor too much.
Do you have access to the room bellow or you must do everything from up top?
For mass and cost you can't beat concrete, but it won't help much if there is a lot of flanking transmission into the floor cavity from bellow. Mass helps but not as important as decoupling and air sealing.
Aedi,
MLV and underlayment are typically used to prevent structure-borne sound from the space above. if you are primarily worried about sound attenuation the other way there are a number of simple floor/ceiling assemblies that are very effective.
My go-to one, which I find most trades can do without much problem is:
- Floor framing with mineral wool batts
- RSC-1 sound isolation clips.
- Resilient channels
- Two layers 5/8" drywall.
With a bit of care sealing, and avoiding bypass opportunities, it works.
+1 for Malcolm’s advice regarding the use of double 5/8” drywall (for mass) and resilient channel. Mineral wool between joists will help too. Mineral wool is much better than fiberglass for sound deadening. All of this require access to the ceiling in the lower level though.
I haven’t really found anything works all that well in a floor to dampen footfalls and the like except for heavy carpet with padding. The only other thing I can think of trying would be a layer of cork, but I don’t know if that will accomplish much. Soundboard, which is something of a dense but loose fiberboard, is often used in floor assemblies but the results tend to be mixed.
You’ll have the best results using 5/8” drywall suspended on resilient channel on the ceiling below. Add mineral wool between joist cavities and you’ll have a very noticeable reduction in sound transmission.
Note that “real” drywall (not ultralight) is best for soundproofing due to the higher mass.
Bill
We used EPDM on a project not too long ago. It was more for weather protection but we figured it would help with sound as well.