DO I need to use wall ties?

[jimAuk]

Hi

I am bricking up a previous externall door to install a window.

The size of the brickwork will be 1.70m wide by 0.8m tall, it will be double skin with a cavity filled with insualtion.

Do I need to use wall ties for such a small size?

 

[jimAuk]

Think I have found my answer now>?

every 450mm verticly and 750mm widths. Starting at DP level.

So if that is the case for my wall, I will have 2/3 on the DP layer, 2/3 at 450mm layer and 2/3 under the top layer of bricks.

This links in well with the cavity boards I have got which are 450mm width (height)

 

[RedHerring2]

I think I remember seeing advice that wall ties shouldn't be used on the same mortar course as the dpc. I think it was on Kingspan or Xtratherm web site.
I assume that it's to avoid puncturing the dpc.

The wall ties around any previous unbonded jambs may have been increased.

 

[jimAuk]

I am also going to tie the new wall into the opening with the use of drilled ties.

 

[r896neo]

put a bit of expanded metal along the joint between old and new before replastering the inside to stop it cracking.