i'm trying to build a sound "proof" room in my basement. for floating the floor, i was thinking about using the Auralex u-boats.

http://www.auralex.com/sound_isolation_ ... _uboat.asp

however, i can't seem to find any information on the compression force ratings for these things. the only information thta seems to be on the website is to place them 16" apart on flooring beams. but, it doesn't give a maximum weight rating to the room based on the number of u-boats used. if the room is too heavy, it's going to compress the u-boat all the way, making it completely useless since vibration is going to be passed down anyways.

my problem is that i'm building the room on REALLY f'd up concrete, and so we have to make adjustable feet in order to level the floating floor on the concrete floor. if i can find the compression ratings, i think i can do some math-a-magic and figure out how many feet to use, as well as where to put them.

so, anyone that has had experience with these, please let me know.

thanks.
-mikeC

i'm trying to figure

The UBoats, and any other product serving the purpose of an isolator, must compress to some degree in order to work. You have two sides of the coin...if there is no compression it will not work and if it is fully compressed it will not work.

You have to establish the real dead and live load combinations (not the building code "safe loads") in order to determine what will work. You also have to take into account the long term effect of this load on the materials involved to account for degradation.

If you find any published data from Auralex that indicates the compressive strength of the UBoats...please post it. I have yet to find it.

i've put in a call to the Auralex tech support asking those very questions. (max compression depth to avoid and recommended compression depth(s) for operation).

i'm hoping they get back to me soon. i left a voice mail for the main engineer.

i'll keep you posted.

basically what i've found is that there is no specific data on the compression rates per area for the u-boats. Auralex just defines the number of u-boats to use for a certain area (every 16" for center joists, and every 12" for perimeter joists). they don't appear to give a weight rating for this area, so there must be some implied assumption of average weight here. i'll be damned if i can find it.

but, i did find out that the u-boats are made of an EPDM rubber, with a durometer rating of 60. i googled the definition of the specs for about 10 minutes, and then lost interest.

and, as an FYI, you can buy sheets of EPDM through local rubber distributors. and from what i've been able to glean from the interweb is that tires are also made of the same stuff. so, you could just use some old tires to do the same thing.

that's all i got.

I'm thankful for this post because it gives me something to go on for the room
I'm building.

Thanks for the follow up. I was hoping that Auralex would come through with some actual specs...but oh well.

as a weight maximum, Auralex has said that the floor itself (normal construction with 2x4s 16" on center) will fail before the U-boats reach their maximum compression. while this wasn't the excessively detailed answer that i was looking for, it's close enough for government work.

so, build on!

Unless you have an unusually high ceiling in your basement, you may want to look into the Kinetics RIM roll out floor isolation system.

http://www.kineticsnoise.com/arch/rimwood.html

The main benefit for your application is that you won't have to build up so high (no 2x4's required), and you will probably save some dough.

It is a 1" high product that has high density product spaced out on a fiberglass mat that you roll out. At that point, you lay sheets of ply right on it, so that's it in terms of height.