John Sayers' Recording Studio Design Forum Archive

Hi!

I`ve been reading this great forum for a while but this is my first post.

I`m planning on building practice-rooms in a large steel hall with the use of free standing cells of about 30 kvm each, using room in a room design. This steel hall have been used for storaging of containers, so it seems robust in its construction. This will be on the 1. floor (above the groundfloor).
I`m planning on using 20mm rigid fiberglass (705??) under a couple of layers of 25mm fiberboards as a floating floor. My concern is the halls steel floor; when you jump on it rumbles a bit. Can this steel floor give me problems compared to a concrete one? Say that the room below will work as a big resonator? There will be no one below, but outside this hall 20 meters down the road there will be neighbours.... Should i be concerned and maybe reconsider my floating floor technique?

What do you guys think?

Thanks

SL

Can you give more details of the construction, such as size and spacing of frame members, thickness of the steel floor, and what's a KVM?

Using somewhat compressed insulation (not closed cell foam) between the steel and the wood floor will help damp the vibrations, both in the steel and in the wood floor - you might also need to use something like spray-on foam or cellulose UNDER the steel for more damping, depending on the severity of the vibrations...

Also, even steel can break - so you'd need to figure out a floated floor plan that doesn't concentrate the weight of your rooms where there is no support under the steel flooring... Steve

knightfly...

kvm is square meters ..
it´s a scandinavian thing..=)

Thanks for your reply Steve!

Oops, KVM was a slip of my native tounge... I meant m2 - square meters.

I can give more details on the construction when I`ve had a much closer look & maybe taken some pictures.
BTW here`s a link to compressed fiberglass I`ve been thinking of using:

http://guide.rockwool.no/sw14502.asp

From the picture of the product, can you tell what you call these things in the States? Is this what you call 705?
They also come in 50mm. Will 50mm give better results than 20mm, or is it better to put the money into building raisers for drums and bassamps inside the rooms on top of the already floated floor?

thanks

Stein

In north america we have:
fiberglass - including 705, made from silica
rockwool - made from basalt slag
Both fiberglass and rockwool are mineral wool.

http://www.bobgolds.com/AbsorptionCoefficients.htm shows absorbtion coefficients for both.

Fiberglass comes in two flavours: rigid and fluffy. Fluffy is usually things like pink R19 batts by Owens Corning, and rigid is often yellow and denser. http://www.ethanwiner.com/oc-703.jpg

rockwool I've only seen in rigid, and it's usually grey.

Rockwool is usually denser than fiberglass to equivilent absorbtion. Rockwool often can take much higher temperatures without melting.