Gearslutz.com - View Single Post - "Floating floors in the control room" Who's done it?

Ethan Winer · 30th December 2002, 07:52 PM

Craig,

> we're about to install the floor in the control room and are pretty set on the Auralex rubber feet and 2x6's ... what did you use to ill the void between studs? <

I built a pro studio years ago with floating walls, ceiling, and floor. Here's what the acoustic consultants had us do, which was fairly cheap and worked very well:

Place a layer of 2-inch thick 703 fiberglass board on the underfloor, then place two layers of 4x8 sheets of 3/4-inch plywood on top of that. Use two layers of plywood for stiffness (so it doesn't flex) and strength. Very important: be sure to use both glue and screws to join the two layers of plywood. If you don't use a liberal coating of glue and lots of screws, the floor will squeak as you walk around. Also, lay one layer over the other so one board straddles the ends of the two below. That is, if the lower boards are running north-south, make the upper ones go east-west. This way the upper boards straddle the joints in the lower boards.

Besides providing excellent isolation, this method avoids the need for studs, framing, rubber mounts, etc. In fact, since I assume you're floating the floor to increase sound isolation between rooms, the real goal is to decouple the two floors. Fiberglass will do a better job than studs and sand which add mass more than decouple.

One caveat: This was twenty years ago, and we might have used 705 instead of 703. I don't remember for sure. Hopefully someone else here is familiar with this method, and can advise which fiberglass material is better suited.

--Ethan

30th December 2002, 07:52 PM	#9
Ethan Winer Lives for gear Join Date: Oct 2002 Location: New Milford, CT, USA Posts: 5,076	Re: "Floating floors in the control room" Who's done it? Craig, > we're about to install the floor in the control room and are pretty set on the Auralex rubber feet and 2x6's ... what did you use to ill the void between studs? < I built a pro studio years ago with floating walls, ceiling, and floor. Here's what the acoustic consultants had us do, which was fairly cheap and worked very well: Place a layer of 2-inch thick 703 fiberglass board on the underfloor, then place two layers of 4x8 sheets of 3/4-inch plywood on top of that. Use two layers of plywood for stiffness (so it doesn't flex) and strength. Very important: be sure to use both glue and screws to join the two layers of plywood. If you don't use a liberal coating of glue and lots of screws, the floor will squeak as you walk around. Also, lay one layer over the other so one board straddles the ends of the two below. That is, if the lower boards are running north-south, make the upper ones go east-west. This way the upper boards straddle the joints in the lower boards. Besides providing excellent isolation, this method avoids the need for studs, framing, rubber mounts, etc. In fact, since I assume you're floating the floor to increase sound isolation between rooms, the real goal is to decouple the two floors. Fiberglass will do a better job than studs and sand which add mass more than decouple. One caveat: This was twenty years ago, and we might have used 705 instead of 703. I don't remember for sure. Hopefully someone else here is familiar with this method, and can advise which fiberglass material is better suited. --Ethan