Extension PIR insulation wrong size!

[Deb65]

Hi all need advice please. We’re self building a small extension to rear of property, building regs have been out and advised we need to replace pir insulation to ensure a 50ml gap, we’ve managed to remove it without out knocking the wall down, but now need to refill the cavity. We had to cut wall ties to enable us to do this so we’re hoping that the following plan would be achievable.. install large pieces of pir boards and stick to wall and drill through retrofit wall ties. Would this be acceptable? Can’t think of any other way to do this, any advice would be appreciated thanks

 

[freddiemercurystwin]

Jeez, this is why you get drawings done.

 

[jono_h]

You’re going to struggle to get the boards to butt up tight to each other and you won’t be able to tape the joints. I’d be surprised if your Building Inspector accepts it.

 

[mattylad]

How are the wall ties going to be repaired now It's done?

 

[Deluks]

I can see it being quicker to knock down inner skin, if lightweight blocks.