Bricking up external door - help

[RVS6]

Hi

I am about to brick up an external door in an external cavity wall. Both leaves are brick with a 75mm cavity (1960’s build). Two items that I need some advice on are as follows:

1. The cavities at either side of the opening are closed with brick – do I need to cut the brick out to fully expose the cavity?

2. Will it be okay to use thermalite/breeze blocks on the inner skin? I have plenty left over from other work. Just worried about cracking between the existing brick and the new block as they are different materials. The internal walls will be fully plastered so would some EML nailed to the thermalites before plastering eliminate cracking? I will be putting wall starters in to anchor the blocks.

Comments would be much appreciated.

Cheers

 

[tony1851]

1. If there is a vertical dpc already in place, no point in cutting the bricks out to maintain the cavity.

2. aac blocks do shrink, though the lateral shrinkage on the width of a doorway will not be that much, but a strip of em lath
would not go amis.

 

[^woody^]

If you leave the closed jambs in, then you risk having two lines of pattern stained decorations where the solid wall is cooler than the cavity wall each side of it. It depends on the room usage. It's a risk not a certainty, but a risk all the same. Take it or leave it.

You are better off using fishtail ties and not a wall starter and these wil reduce the potential for movement, but either way the joint will likely crack. You are better off hacking plaster off either side and boarding across or fitting some mesh.

 

[RVS6]

Thanks Woody
I think I will cut out the brickwork jambs rather than take a risk.
I have already fitted the wall starters, is it likely to make that much difference? There would be a tie at each course of block. If I chose to put in the fishtail ties would this be at every other course?

Noted on the mesh - will get the plasterer to include for this, then hopefully no cracks!

Cheers

 

[^woody^]

If you have fitted the starters then leave it at that. But yes, fishtails would be every block course