Bonding 100mm to 75mm cavity internal wall

[baker332]

Ah see you modified the drawing woody so a literal step in, straight block work, beyond the spreader.

Any reason it's not possible to angle brick work?

 

[^woody^]

Why would you angle it? Isn't the extension perpendicular, with parallel leafs.

Normally you would build it with the step and then line the plasterboard flush across the new and existing wall.

 

[noseall]

Normally you would build it with the step and then line the plasterboard flush across the new and existing wall.

We used 25mm Celotex, foam bonded directly to the wall, on our last 100mm/75mm job.

 

[^woody^]

We used 25mm Celotex, foam bonded directly to the wall, on our last 100mm/75mm job.

Yes that's the principle that I normally specify, and it brings the existing wall up to similar insulation value as the new wall.

 

[baker332]

Why would you angle it? Isn't the extension perpendicular, with parallel leafs.

Normally you would build it with the step and then line the plasterboard flush across the new and existing wall.

Thanks, I get it. Just that angling the block seems to work? I started this, and if it's not the right way of working will take it down, but see photo this is the block angled from old on the left new on the right:

 

[^woody^]

Building is not a science.

There are established principles that are known to work, and other non-standard ways that will work and other ways that might or might not.

If you are asking if a competent bricklayer would do that, or is a person specifying or managing that work would accept that, then the answer is no.

If you are asking "I've done this now, will it be OK?" then the answer is, "it might be, it might not, its a risk". Yes you can board over it and then its all hidden, even if it does crack.

The angling of the wall is not as big a concern as the excessive vertical straight joints and minimal bonding.

 

[baker332]

Thanks Woody really interesting, I'll get this seen to then. It seems some builds will butt up to the new build assume hopefully with a wall starter to prevent the excessive vertical joint, but in this case I've not done that or toothed in enough.

Thanks for the feedback.