Garden Pool House/Band practice/recording/Cinema/Guest room

[a366666643]

That means no insulation voids.

How would you fill the void here in the double stud pic? Use 25mm batts laid horizontally all the way along in between the studs and the main thick batts?

but the larger room design seems off to me. It appears to have an inner leaf everywhere except the windows. Also, the ceiling it's decoupled so why are you adding an inner leaf there at all?

The larger room is not decoupled from the structure. But it will have the block outer leaf and a stud inner leaf, which goes up to the roof joists. The ceiling in that room should be attached directly to the joists. I'll get the architect to clarify on the drawing. Thanks!

Also, why aren't you maintaining your spring gap size between the two rooms the same as you are to the exterior wall? That smaller gap will increase your resonant frequency. In your Sept 12th diagram, it looks like you have things correct. This new one isn't the same as you had initially planned.

Yes, the gap size will be the same - I'll get all the changes done to the drawing at the same time. The 12th Sept drawing was my scribbling.

Thanks for pointing these things out!

[Waka]

Just to clarify, according to your designs:

Your home theatre room is the only room that is sound isolated.

The larger room is standard timber frame wall with external block facing, these are coupled. These have standard double glazed doors and windows.

The home theater is fully decoupled room within a room. An internal self supporting timber frame is erected inside this room and supports a second set of joists that your independent ceiling is attached to.

The home theater has two solid core doors, one on each of it's frames.

Are the above points correct?

I'm not really certain on how your architect has designed the home theater. Have you told him the block wall can't be coupled to the timber frame in this room? Because he's drawn a single skin block wall here in front of your inner walls, but there's no mention of how the block wall will be supported. Single skin walls in the UK require support piers every 3m. It's not usually seen on buildings these days because you would usually couple it to a second internal skin of block/timber frame. But we can't do that for obvious reasons.
Also are they happy to have the home theater section of the blockwork completely sealed (that is without any brick vents).
The deviding wall between your large room and home theater will need to have heavy mass on the large room side too, as this is your outerleaf for the home theater MSM system yes?

Dan

[a366666643]

Just to clarify, according to your designs:

Your home theatre room is the only room that is sound isolated.

Yes

The larger room is standard timber frame wall with external block facing, these are coupled. These have standard double glazed doors and windows.

yes

The home theater is fully decoupled room within a room. An internal self supporting timber frame is erected inside this room and supports a second set of joists that your independent ceiling is attached to.

yes

The home theater has two solid core doors, one on each of it's frames.

yes

Have you told him the block wall can't be coupled to the timber frame in this room?

yes

Single skin walls in the UK require support piers every 3m. It's not usually seen on buildings these days because you would usually couple it to a second internal skin of block/timber frame. But we can't do that for obvious reasons.

hmmm, I didn't know that. That's quite important... I'll need to talk to him.

Also are they happy to have the home theater section of the blockwork completely sealed (that is without any brick vents).

It hadn't come up in conversation, although when I asked him about the interstitial condensation risk, he said we have the 50mm clear in the "cavity". Again I'll need to talk to him.

The deviding wall between your large room and home theater will need to have heavy mass on the large room side too, as this is your outerleaf for the home theater MSM system yes?

I had planned the 2 plasterboard layers, on both sides of the double stud.

[a366666643]

I've had a reply from the architect. He had been expecting to use acoustic frame cramps to tie the 2 walls together like these, but he hadn't discussed with me. I'm not sure how much compromise is involved here.

https://www.ancon.co.uk/products/wall-t ... -wall-ties

He'd also expected to use drill vents in the outer leaf.

I'm not sure whether this negates all the effort put into the rest of the isolation?

[Gregwor]

Those clamps say that they isolate above ~140Hz. That's not low enough for what typically require in the recording world.

Also, you know the answer to your last question. Any hole in your outer leaf will trash your isolation.

Greg

[a366666643]

Also, you know the answer to your last question. Any hole in your outer leaf will trash your isolation.

hmm, what are my options if I need the outer leaf sealed?

[Gregwor]

hmm, what are my options if I need the outer leaf sealed?

Does your architect have any options for you?

Greg

[Waka]

I've had a reply from the architect. He had been expecting to use acoustic frame cramps to tie the 2 walls together like these, but he hadn't discussed with me. I'm not sure how much compromise is involved here.

https://www.ancon.co.uk/products/wall-t ... -wall-ties

He'd also expected to use drill vents in the outer leaf.

I'm not sure whether this negates all the effort put into the rest of the isolation?

Sorry, I hadn't realised you had replied! Yes, that's why I asked . Studio construction can't use traditional construction methods and architects don't often realise this.

As Greg said the wall ties probably aren't sufficient at decoupling to be useful. Can you ask you architect to add internal support piers to the home theatre section? Then make the air gap about an inch greater than the support piers extend inwards.

Here's an (amazingly crafted and beautiful) sketch of something that would work acoustically and should satisfy Building Control:

MSM sketch.png

If they refuse to accept the block wall being completely sealed, then you'll have to go three leaf. Let the builder build the entire shell as timber frame coupled to the blockwork as usual (minus the internal plasterboard in the home theater). THEN build a third leaf inside your home theatre completely decoupled. You're going to lose at least 200mm of length and 100mm width in your home theater though this way. You may want to extend the Home theater's width to account for this in your design.

This would be more expensive as the Home theater will now have to have 2 sets of load bearing wall frames in it now.

Dan