John Sayers' Recording Studio Design Forum Archive

Rod,

Steve kinda' diverted this question to you since you have more experience with sand filled floor cavities.

Here my thinking so far; (Just ignore that sound of smoke detectors going off)
9. 3/4" T&G Cherry flooring
8. 1/4" "Quiet Floor" Pad
7. 5/8" Plywood - Glued and screwed (Rotated 90 degrees)
6. 3/4" Plywood - Glued and screwed
5. 2x6 Floor Joists and filled w/Sand (double banded on perim?)
4. 1/2" Neoprene "Pucks"
3. 10 mil Poly Vapor Barrier
2. 12"x12" Concrete perimeter footing 1" above "grade" (independant "pads" for ea/room)
1. Earth

Should I fill the joist cavities completely? (Using vibration settling)
OR
Should I fill the joist cavities to within (or slightly less than) 2" if the top of the joists and "over stuff" the remainder with 2" of rockwool or 703 or ??? (to accomodate for the sand settling)

How would you recommend tying the double bands together? Glue and screw? Glue and threaded bolt? Something else? Single band?
What method for attaching the joists to the banding?

Now the "mad scientist" in me gets unleashed...

OK, I'm creating pads for each room. In the voids between the rooms, (e.g. between the pads and between the pads and the exterior walls) should they too be filled with sand? Or should they be "empty"?

I would think "empty" as the sand has a higher density than air, and therefore would transmit sound energy better than air. Then again... it's mass that kills LF... ARRRRRRRRGH!... mah branebukit hurtz...

BEER!, MORE!, GLUG!, BELCH, GLUG! farrrrrrrt, GOOD better feel! BEEEEER!

Thanx,
xaM

Just wondering if anyone has any idea as to which is cheaper...

Sand filled floors, as specified (or improved upon by those on the know) or concrete?

Thanx,
Max

Max, haven't had much luck getting hold of Rod lately, gotta run to work for now - I'll see what I can do tonite... Steve

xaMdaM wrote:Rod,

Steve kinda' diverted this question to you since you have more experience with sand filled floor cavities.

Here my thinking so far; (Just ignore that sound of smoke detectors going off)
9. 3/4" T&G Cherry flooring
8. 1/4" "Quiet Floor" Pad
7. 5/8" Plywood - Glued and screwed (Rotated 90 degrees)
6. 3/4" Plywood - Glued and screwed
5. 2x6 Floor Joists and filled w/Sand (double banded on perim?)
4. 1/2" Neoprene "Pucks"
3. 10 mil Poly Vapor Barrier
2. 12"x12" Concrete perimeter footing 1" above "grade" (independant "pads" for ea/room)
1. Earth

A few comments here........ with a sand filled deck you really do not gain anything with the pucks....... the sand acts as the dampening agent -

One other item - the vapor barrier really wants to be below the concrete- not above..... otherwise you WILL get condensation on the bottom side of the barrier - and it WILL produce mold.

If the concrete is already in place - then forget the poly barrier and use a chemical sealer for the concrete prior to construction of the deck assembly.

Should I fill the joist cavities completely? (Using vibration settling)
OR
Should I fill the joist cavities to within (or slightly less than) 2" if the top of the joists and "over stuff" the remainder with 2" of rockwool or 703 or ??? (to accomodate for the sand settling)

Fill the cavities completely,

How would you recommend tying the double bands together? Glue and screw? Glue and threaded bolt? Something else? Single band?
What method for attaching the joists to the banding?

You can either toe nail the band together - or you can use angle brackets on the inside face - your choice - and you only need a single band.

The joist can be toe nailed into the band with 4 16d nails - or you can use joist hangers to assure connection - once again - tis your choice -

Now the "mad scientist" in me gets unleashed...

OK, I'm creating pads for each room. In the voids between the rooms, (e.g. between the pads and between the pads and the exterior walls) should they too be filled with sand? Or should they be "empty"?

I would think "empty" as the sand has a higher density than air, and therefore would transmit sound energy better than air. Then again... it's mass that kills LF... ARRRRRRRRGH!... mah branebukit hurtz...

Don't use anything - think about it for a moment - you will have dead air space between the walls - and sand dampened floor - you will gain nothing by putting anything in that void space.

Rod

rod gervais wrote:A few comments here........ with a sand filled deck you really do not gain anything with the pucks....... the sand acts as the dampening agent -

That's GREAT news... another cost savings!

One other item - the vapor barrier really wants to be below the concrete- not above..... otherwise you WILL get condensation on the bottom side of the barrier - and it WILL produce mold.

If the concrete is already in place - then forget the poly barrier and use a chemical sealer for the concrete prior to construction of the deck assembly.

Haven't even dug the first shovel full yet, so I have time to take care of the poly issue.

You can either toe nail the band together - or you can use angle brackets on the inside face - your choice - and you only need a single band.

The joist can be toe nailed into the band with 4 16d nails - or you can use joist hangers to assure connection - once again - tis your choice -

Rod

Thanks Rod! So, I'll go single band with joist hangers, fill the cavaties completely with sand and put the poly below the concrete footings.

Thanx!!!

Max