John Sayers' Recording Studio Design Forum Archive

knightfly

but it WILL reduce flanking noise into the house (and vice-versa)

I agree, but I would have phrased it differently.
Concrete is great at stoping airborn sound, but lousy at stoping structural born sound (i.e. Sort of: once the sound is moving the concrete, the concrete is a great conductor of sound). Decoupled concrete, say in a separate building, works well.

Greetings

My Studio build is in a double garage adjoining the house. THe house walls are double leaf ( brick - airgap blocks ). Which means one side of the studio is triple leaf.

To be honest, after tests do far, this triple leaf wall isn't doing any harm. I dont think hendriks proposed design is bad. I would put a door into the studio from the house. Just as I did myself.

Steve is right about the weight of a concrete floated floor. I made my supporting concrete slab 150mm thick with about 400mm thick edges.

You don't need steel reinforcement for the supporting slab, but you DO for the floating slab. The are positive and negative moments in the floating slab. I used 1/2" rebar on 300mm centres in the centre of the slab. MY floating slab is 125mm thick.

Depending on your building codes, you may need insulation under your supporting slab. I did, and used 70mm celotex floor insulation.Amazing stuff, it supports tons of weight.


Paul

Thanx Paul. You helped me al lot. Now i am trying to do a good design and I will post it here later... So Thanks all.

regards

Hendrik

Sorry I ahvent' been abck for a while. This forum onyl sesm to be working at some times fo the day - bizarre?

Hendrik wrote:Wow!!!

Thank you very much Paul. Now I understand it and know how to built this Floating Floor.... Building the Walls on the Floating floor is a good point. Sometimes I think to complicated...

But I have 2 other Question... :

1. Is a 15 cm Concrete on the sylomer enough? I know I have to calculate the load to choose the right sylomer, but is it enough to build everything up (Walls etc.)?

Yes. More the better really. I used a 125mm (12.5cm )slab on the sylomer.

2. How did you realise the contact between the walls and the ceiling, or did you build up the ceiling on the wall frame?

The WHOLE ROOM floats on the concrete slab, so the ceiling joists simply rest on the stud walls ( atatched with truss clips and very long screws )

3. (perhaps Steve?) My building is a standard "Brick House" which means that I have a Brick - Insulation - Clay brick System as the Outer Walls.

Now, when I build up the inner walls (only these ones which stands parallel to the outer Brick), I have a 3 Mass System. Or not? How can I handle this?

Thanks that you help me.

Regards
Hendrik

Hendrik, the left wall of my garage is teh wall of the house. It is, like you place, a double leaf wall - Brick - air blocks. Even though this section is 3 leaf, it's still VERY SOUNDPROOFED. But then I'm using 6 layers of 12.5mm drywall and 1 layer of 18mm MDF on my inner room walls and ceilings.

Here's a description of my floor system from Soil upwards.....

1] 100mm Hardcore
2] 10mm blinding sand
3] DPM ( damp proof membrane )
4] 70mm Celotex Floor insulation
5] DPM
6] 150mm Concrete oversite base - Fibre Mesh mix. NO steel reinforcing
7] 50mm high Sylomer blocks- 50m air gap filled with 45kg/m3 Rockwool
8] 18mm PLywood formwork
9]125mm Floating concrete Slab - Fibre Mesh mix with steel reinforcement

Calculated to about 9 to 10Hz - POssibtyl even lower in practise as I've added some more weight to the design since then.

When you calcualte the weight for the sylomer, you MUST also include the walls and ceiling, and any other heavy items that will be in the studio.

In practise this means the edges of the floating floor will be more densely populated with sylomer, as of course the extra loads due to ceilng and walls are on the edges.

To do this I divided the floor up in to ZONES. Each wall footprint was a zone, and the main usable floor area was another zone.

Roughly the main flor area had 80mm x 82mm sylomer blocks on a 550mm grid. The wall zones had 60mm x 125mm sylomer blocks spaced about 200mm apart


If you look at my studio build diary http://forum.studiotips.com/viewforum.php?f=1( can't rememebr which page ) you can see piccies of how I laid out the blocks, and how I spent a lot of time getting the heights of each block as close to being the same as possible. Otherwise the load on each block will be different and the floor won't work so well.

hth


Paul