Is a UK house wall already two leaf?

[garethmetcalf]

Hi
We are buying a house with a downstairs room that I will be using for my studio. I will be working on a detailed plan once we have the house and I can check dimensions properly etc, but I need some advice about sound reduction. The room will be mainly used for mixing and vocal recording, rather than full bands.

The house is in the UK built in 2002 from brick, so I'm assuming outside walls are breeze block and brick, and interior walls are stud wall. http://www.fidler-taylor.co.uk/Water-La ... 20Q8U.aspx

The room is 5.43m x 2.43m and on the ground/basement floor, above it is the kitchen and lounge. The short back wall is an outside wall but is actually underground as the house is on a hill, one long wall is an outside wall that is partially underground (the slope of the hill), the other long wall is an inside wall with a hallway the other side, and the remaining wall is actually a patio door to the front.

My biggest concern is sound transmission between the studio and rooms above (and vice versa).

My current thinking is: Remove plasterboard from ceiling and inside stud wall, add plywood to the underside of floorboards between ceiling joists. Build new stud wall frame on the inside of the stud wall (and mount double layer plasterboard on the inside), and build a new ceiling frame from this across to the outside wall so that I can hang double layer plasterboard new ceiling on this (mass-air-mass).

My first question is: Would it be OK to support the new ceiling between 3x2 mounted to the outside wall and my new inside stud wall, or would I be better building a new stud wall all the way around the room? (worried that this might create a three leaf system on the outside wall...?)

My second question is: For the patio door, would another patio door mounted inside the room (connected to my new interior wall) provide any useful additional sound reduction? (i.e. worth bothering?)

I hope this makes sense and will have a go at drawing out if necessary!

Thanks very much

[Soundman2020]

Hi there Gareth, and Welcome!

My first question is: Would it be OK to support the new ceiling between 3x2 mounted to the outside wall and my new inside stud wall,

Not such a good idea! That would directly connect your inner-leaf to your outer leaf, creating a clear flanking path. Also, since you'd only be isolating the room on two sides, your isolation would not be very good...

or would I be better building a new stud wall all the way around the room?

Correct!

worried that this might create a three leaf system on the outside wall...?)

You didn't mention how that wall is built, so it is possible that you could end up with a 3-leaf. But that would not necessarily be the end of the world: you can compensate for the reduced low-end isolation by putting more mass on the "middle" leaf, and increasing the size of the air gap, until you get things back where you want them.

My second question is: For the patio door, would another patio door mounted inside the room (connected to my new interior wall) provide any useful additional sound reduction? (i.e. worth bothering?)

You are building a "room-in-a-room". It's a new self-supporting and fully independent structure that sits inside the existing house. Like any other room, it needs doors! So you will need two doors, for sure: one in the (existing) outer leaf, and one in the (new) inner leaf. They will be "back-to-back", and open in opposite directions. The outer-leaf door must open towards the outside, and the inner-leaf door must open into the room. Both must have the same surface density of the wall they are in, and both must be completely sealed all around the full perimeter, with at least two full seals.

I hope this makes sense and will have a go at drawing out if necessary!

A diagram would certainly help, but an actual SketchUp model of the entire studio would be much better...


- Stuart -

[garethmetcalf]

Hi Stuart

I'm really sorry that I didn't reply to your reply. We had been preparing for and then moving and I haven't had chance to come back to the forum.

Since posting this question and actually moving into the house I've come to the conclusion that the space I have for a studio isn't going to work. It's too narrow and given the amount of work needed to make it quiet enough (traffic, footsteps above etc) it would shrink even further.

I am busy reading up on this forum and in Rod's book (again) and devising a plan for a wooden garden studio - built from scratch, room in room.

I'll start a new thread asap

Thanks again
Gareth

[Soundman2020]

Devising a plan for a wooden garden studio - built from scratch, room in room.

Cool! Looking forward to seeing that project progress.

I just noticed whereabouts you are in the UK as well: my dad was from Derby itself. Small world!


- Stuart -

[garethmetcalf]

Small world indeed! I work at the University in Derby...

Anyway, my new thread is started. I'm very excited about finally getting to build a studio from scratch!!

Thanks
Gareth