Wall tie kit on extension not tight

[Donnapaddy]

Hi we are having a single extension and builder is using wall tie kit the long strips that fit on the wall.our house has solid poured concrete that's tough to get in to ,so the wall tie has a lot of play in as it's not tight to the wall.does this matter as builder has said it doesn't as the brick cement will help hold it ...we are novices so help please

 

[cAtLeYx]

He could argue the mortar from the blockwork / brickwork will "bind everything together". I wouldn't accept this and would ensure that the "wall starter" is securely fixed. One other point to ensure is that he cuts a vertical slot within the existing concrete and inserts a DPM, this cut should be within the cavity and will ensure any damp from the outside face of the existing wall does not bridge the cavity and causes "cold bridging / damp on the inside.

 

[Donnapaddy]

Thankyou .they have put a dpm under the new floor ,and on first course of bricks is that what you mean ,also the cement in the brick work today is still a bit crumbly but is has been raining since it was done .will that be OK .it's a big expense and im worried that since its been started it's constantly been wet

 

[^woody^]

If the house is rendered, has he knocked the render off to fix to the smoother concrete wall?

Or is the house something like a Wimpey no-fines construction, where the wall has a rough concrete finish?

 

[^woody^]

One other point to ensure is that he cuts a vertical slot within the existing concrete and inserts a DPM

Vertical DPC

 

[cAtLeYx]

I stand corrected Woody - DPC

 

[Donnapaddy]

It is the wimpy no fines and the render is flat as it's worn off over years

 

[cAtLeYx]

How many courses of brick have been laid. Its always good practise to cover brickwork to keep the rain / elements out. You really want to keep the cavity, blocks/bricks & especially the insulation as dry as possible during construction. Unnecessary saturation during construction will cause internal issue for you once the structure of the building is complete. The warm internal temperatures will pull the moisture inwards and therefore may cause an extended drying out period.

 

[tony1851]

If it's a no-fines house, the walls are like Crunchie bars and it is almost impossible to get screw-fixings in.
It's not surprising the starter strip is loose. Maybe he should have used resin-fixing, to fill the inevitable
over-sized holes.

 

[^woody^]

Generally, any rough surface should be flattened as much as possible by chipping any pebbles away to make the wall starter strip sit as flat as possible against the wall. Then if the fixings are not tight, they should use resin plugs into the concrete as Tony says.

If the strip is not flat against the house, it looks a right mess when it comes to pointing it up with mastic.

 

[Donnapaddy]

Thankyou