Garage conversion wall design

[DIYMike]

Hi, I am doing a conversion and I'm unsure how to do new internal skin block / brickwork, Should it join onto existing walls or be kind of floating? It would obviously have wall ties to outer skin which would be using wall starters. Please see diagram.

scan_250708-093100.pdf

[Redbeard]

The sketch shows no insulation to the exposed side wall. Is this the intention?

[DIYMike]

Sorry if my sketch isn't clear, yes I was intending to have insulation on all four walls. Because the garage is so narrow I was just going to fix insulation with plasterboard already stuck on it (I don't know what it's called) straight onto the long side walls.

[Nickfromwales]

3 hours ago, DIYMike said:

Hi, I am doing a conversion and I'm unsure how to do new internal skin block / brickwork, Should it join onto existing walls or be kind of floating? It would obviously have wall ties to outer skin which would be using wall starters. Please see diagram.

scan_250708-093100.pdf 314.36 kB · 7 downloads

Why not do the internal structure in timber frame? The brickwork connecting to the outside wall will be a huge cold bridge. 

[DIYMike]

Thanks NickfromWales that sounds like a good idea. Unfortunately for me (and I was trying to avoid explaining in detail) I have already built the walls. after finishing the front, I sat down to look at my handiwork and came to the same conclusion, I'd just made a huge cold bridge. So now I was thinking, what if I cut back 100mm off the ends of the internal skin and inserted / extended the long wall insulation. Do you think that would get through building control?  

[Nickfromwales]

7 hours ago, DIYMike said:

Thanks NickfromWales that sounds like a good idea. Unfortunately for me (and I was trying to avoid explaining in detail) I have already built the walls. after finishing the front, I sat down to look at my handiwork and came to the same conclusion, I'd just made a huge cold bridge. So now I was thinking, what if I cut back 100mm off the ends of the internal skin and inserted / extended the long wall insulation. Do you think that would get through building control?  

Doubt the wall will have any stability if it’s not mechanical tied in at the end.

 

You’ve tried to avoid the detail, lol so I’ll try to avoid telling you I’d make it the better job and remove the walls and replace with stud and insulation or just the insulted boards as you say .

 

Assuming you’ll need insulation 3-4 sides around you’ll be better off either the timber frame (3x2) with PIR inlaid, and another 25mm over the front of studs (if you can afford to lose another inch of interior space?). Building control may allow you to just dot and dab insulted plasterboard straight on to the external leafs, if so, removing what you’ve done will free up more internal area, assuming you’re already allowed to just insulate the side wall then you should be allowed to do the same 3 sides around?
 

Obvs ceiling insulation needs beefing up too.