What do you think of Cow Mats for Soundproofing?

TWerner

Senior Member
We're getting closer to breaking ground on a new home, so I've been thinking a bit about soundproofing.
In the room I'm concerned with, the floor is the most important thing to soundproof, and looking at the prices of underlayment, they seem like a rip off. So I thought I'd run the idea of Cow Mats by you.
I have cow stall mats under the weight lifting equipment in our current home, and given the prices of vinyl or heavy rubber underlayment, cow mats seem like a much better option. Each mat is 4'x6', they're made of heavy rubber about 3/4" thick, and they weigh around 90lbs each. To carry them up to our current gym, we rolled them as best we could and had two guys to carry each, so they may weigh more than that.
The cost is about $1.60/sq foot, so they're actually cheaper than carpet.
What do you think?
 

iwantmemoney

Senior Member
Haha! No one can answer cuz no one knows what they are! Sounds legit. How do you cover them to make a solid walking surface? Plus, I make it a habit of never buying carpet over $1.60/sq so watch out.
 

TWerner

Senior Member
I guess they're also called horse stall pads, but I learned about them because the gym supply company I bought equipment from in Vermont was close to a TractorSupplyCompany location. They recommended "Cow Mats" over the interlocking rubber tiles.
I know a lot of people use them for flooring in cross-fit since they are the cheapest way to get heavy rubber flooring.
As to covering them, I suppose you could put anything you wanted over them. In my gym area, I didn't cover them.

The only downside to them is that they smell/off-gas like stinky rubber for a few weeks if they haven't been sitting outside at the animal/livestock supply place you buy them.

I was wrong though, they don't weigh 90lbs, they weight 100lbs each. http://www.tractorsupply.com/en/store/rubber-horse-stall-mat-4-ft-x-6-ft
So the numbers work out to :
20.2kg/sq-meter or 4.2lb/sq-ft Heavy!
 

Aeolian

Platinum Member
That would give you damped mass, but no isolation. If you can get them cheaper than other forms of mass it may be part of a properly designed room. Somehow I don't think that it's cheaper than 2 or 3 layers of 5/8s drywall though.
 

TWerner

Senior Member
I think mass wise two sheets of 5/8" thick green board or a higher density drywall would give you almost exactly the same mass/area as these per square foot.

These cost about $40 for a 4'x6' mat, so they are definitely more than 2 sheets of drywall which would run you around $25? But to get damped mass, you'd need to add green glue too, wouldn't you? How much would two sheets of drywall and green glue cost, versus one of this plus one sheet of drywall?

Honestly though, I was only thinking of these for use in a sub floor.
 

StickIt

Senior Member
These would definitely have excellent sound isolation properties!

Without factoring in the cost, I would think that you could:
Joists->subfloor->mats->osb or ply->pad->carpet ?

Is that kinda what you're thinking? I just added padding and carpet because I assumed you were gonna do that for the acoustics anyway. Also, I guess you could just skip the osb/ply underlay, and go for padding and carpet atop the mat? I dunno really, but it looks like it could be a really good idea to me...
 

TWerner

Senior Member
Without factoring in the cost, I would think that you could:
Joists->subfloor->mats->osb or ply->pad->carpet ?

Is that kinda what you're thinking? I just added padding and carpet because I assumed you were gonna do that for the acoustics anyway. Also, I guess you could just skip the osb/ply underlay, and go for padding and carpet atop the mat? I dunno really, but it looks like it could be a really good idea to me...
That is what I was thinking, and I don't know if the top OSB would be needed either, since it would probably require screwing through the mats.
The walls are the easy part. There will only be 2, because it is an attic, and the other 2 sides will be knee walls. There is plenty of information on how to manage walls available, so no worries on those, which means that after the floor, my biggest unknown is the roof/ceiling. The home will probably be steel skinned SIPS with a standing seam roof. OSB SIPS are still a possibility. The SIPS roof could transmit sound well to the outside walls because they are incredibly rigid and light. The outside walls will have hat channel and drywall inside with a drainage plane then hardiboard outside.

Since I may need to find a way to dampen the roof, I will probably avoid even hat channel and drywall on the ceiling until we get the drums and instruments up there. If it is decent, we can just add hat channel and drywall, if it is terrible, we'll have to get creative. I will have many sound absorbent panels on the ceiling either way.
 

Aeolian

Platinum Member
The biggest thing is to make sure your architect understands the load (weight) that you intend to put up there. Better yet, have him read Rod Gervais' book and design the room and supporting structure on purpose. Keeping structure born vibrations from overhead rooms is really hard. And most attics are not designed to support the weight of any enclosure that can contain the sound of drums.

When I worked at Dolby, there was a test theater on the 3rd floor. Isolated concrete slab floating on the existing floor with the room built on top of it. State of the art acoustic design and isolation as it is used to test cinema and recording gear. Even the seats have bass traps under them since the rows of chairs typically create a nice resonant tube in most theaters. Anyway, after all the calculations, to make sure the building would still support it, they put a bunch of barrels up there and filled them with water to simulate the load while nobody was under it.

The last thing you need is your studio crashing down onto your family.
 
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