Garage/outbuilding conversion question

Bippu

Active Member
Hi I’ve been hunting around and can’t really find the answers I want for my outbuilding conversion.
I have an existing outbuilding with single skin.
It currently has poly membrane against wall then batting that stops below floor height , 25mm polystyrene. There is a gap between pad an wall I guess it’s used as a little drain and on top MDF panel to sub floor. Dpc is 2 brick up.
1. remove MDF keep place and blackjack floor and walls. 3 coats people have said.
2. Block up the back end windows replace side door and door end windows with double glazing. Replace sliding door with oak door as main entrance.
3. Replace 25mm polystyrene with 75mm celotex except piers have 25mm.
4. 50 mm airgap and sole plate around room.to place new stud work In and decouple from ceiling.

If I fill the stud with additional 50mm celotex Double foil or use a vapour barrier on roomside stud. I can’t have inwall surround speakers and also how do you fit backbox and electrics ? Back box is 50mm as deep as the stud?

8. Plaster board 12.5mm
9. 100mm celotex on floor with chipboard floorboards
9. Fit Fabrics track To plasterBoard
10. Fit 50 mm broad band absorbition rockwool slabs and it round sockets wiring speaker cable etc on stud wall
11. Bulk up ceiling insulation and tie insulation in with wall.
13. Fit ceiling covering
14 . Fit fabric

I’d really appreciate some help in ensuring place will be damp free and resolve wiring paths and any other tips.
I’m hoping to hide everything away behind the fabric wall
I’ve not decided on pj or 85” tv
 

Attachments

  • DD960759-5B27-48F6-8ACF-6DF244F2E1A5.jpeg
    DD960759-5B27-48F6-8ACF-6DF244F2E1A5.jpeg
    331.5 KB · Views: 176
  • D55A8ADE-DF56-4281-9773-B09878FB9C21.jpeg
    D55A8ADE-DF56-4281-9773-B09878FB9C21.jpeg
    256.9 KB · Views: 147
  • 137DE0B4-F880-47FB-B7BC-015FCBCDDE84.jpeg
    137DE0B4-F880-47FB-B7BC-015FCBCDDE84.jpeg
    353 KB · Views: 180
  • 163910EB-AAD6-4C84-A0A3-D8EC0A5B5C91.jpeg
    163910EB-AAD6-4C84-A0A3-D8EC0A5B5C91.jpeg
    487.1 KB · Views: 182

Sfs

Active Member
Single skin block work. Personally I'd clad the exterior on 19mm battens with insect mesh along the bottom to protect from water ingress. Liquid membrane on floor to dpc, 50mm celotex with 18mm glued t&g floating floor. Batten walls internally and line with 50mm kingspan, vapour control layer then plasterboard (dryline or slim) then finish with floor, paint etc
 

Bippu

Active Member
For the floor you could consider this stuff, no idea of the costs;


With my install, I’m considering in wall speakers behind my screen, in 100mm stud wall.
Is your build single skin ? With the I wall I guess it will create a cold spot or create thermal bridging depending if you can get any insulation behind it. ive also decided to create floating floor and insulate.
 

Lesterjd

Active Member
Single skin block work. Personally I'd clad the exterior on 19mm battens with insect mesh along the bottom to protect from water ingress. Liquid membrane on floor to dpc, 50mm celotex with 18mm glued t&g floating floor. Batten walls internally and line with 50mm kingspan, vapour control layer then plasterboard (dryline or slim) then finish with floor, paint etc

I second this. I too have a garage with single skin walls. I damped proof the floor and half way up the walls with Bitumen and a DPM barrier from top to bottom + floor, 2"x3" wood frame with 2" air gap and double layered plaster board, floating floor with insulating between joist. Hope this helps, it looks a good size room........it's gonna be Great.
 

Bippu

Active Member
I second this. I too have a garage with single skin walls. I damped proof the floor and half way up the walls with Bitumen and a DPM barrier from top to bottom + floor, 2"x3" wood frame with 2" air gap and double layered plaster board, floating floor with insulating between joist. Hope this helps, it looks a good size room........it's gonna be Great.
Thanks could I ask a couple of questions please.
Did you put a vapour barrier room side, Behind plasterboard ?
Did you put floating floor in first and build stud wall on top ?
What did you do for heating or a/c ?
What’s you speaker surround setup ? Did you hide cables or put Speakers in ceiling or wall Or on stands around room ?
 

Lesterjd

Active Member
Hi, the vapour went against the wall there was an air gap into the roof void. The garage had a concret floor so would of had a damp proof membrane already but I bitumened about 1 foot in from the wall and layed an acoustic foam membrane which the foor went over.
Stud walled all around, leaving a 2" gap from the wall, then flooring.
For heating I went for a split air con system hot / cold.
I know a lot more now and would of changed a few things if I could go back in time, but I can't. I put my speaker cables in ducting when they left the equipment rack, they went into the roof void, but when they arrived at the speaker end I just drilled a hole through the plaster board. If I continued the ducting in nice simple bends or added a face plate to the wall any changes in cable would of been easier to make.
So yes I hid my cables but could of made more room for adding extra speakers when needed, no atmos when I first built the room. Speakers are hidden apart from the atmos in ceiling and surrounds.
Here is a few photo's to help you:

DSC_0010.JPG

Flooring note the green membrane



cinema ceiling.JPG

Addind the stud wall etc.

Surround set up is 7.3.4 but I have an upgrade itch at the moment and might change my proccessor because I may add wides.
Hope your build goes well, and you may get some better advice, but its a learning curve, the only issue I have is that the room is to small and I wish it was bigger, bigger room= better sound.
 

Bippu

Active Member
Thanks for sharing , I’ll have to checkout that membrane and bitumen paint options. Going to need a lot of paint. I hope to decouple as much as I can.
I was going for a 5.1.2 with a separate hifi option for music.
is it work upgrading to 7.x.x if I have a single listening position. ?
 

The latest video from AVForums

Star Wars Andor, Woman King, more Star Trek 4K, Rings of Power & the latest TV, movies & 4K releases
Subscribe to our YouTube channel
Support AVForums with Patreon

Top Bottom