Cavity Wall Insulation - have I screwed up?

[zappastix]

Hi

Couple of questions about cavity wall insulation.

Last winter we removed a 3m double glazed window and replaced it with
a modern 3m D/G unit.

Three courses of brick had to be added to original brickwork
as new window was not as high.

The wall is a standard brick/block cavity.

A couple of years prior to this we had that 'blown in' insulation installed on the property.

The cavity floor ended up a mess, because we were not working in the best of condition - dark & cold.

So to remove the muck I also removed the blown in material.

The room got very cold, so I went to Wickes and brought some slabs of Celotex.

MY QUESTION

I squeezed as much of the Celotex as I could in the cavity, forcing it to cut either
side of the wall ties.

So much so, either side of the cavity was filled.

The room is toasty - BUT have I screwed up here - should I have left a gap on the outside wall?

I ask because I'm just about to brick up a doorway for a new bathroom, so a new window can go in.

I've brought Wickes Slab Insulation 100mm - but don't know if I should leave an air gap.

So far I haven't had any problems with the cavity filled with Celotex.

Just want to get it right.

Many thanks.


Stephen

 

[Deluks]

There has been problems with foam corroding wall ties, can't remember which type, might have been the sprayed in foam. If your wall ties are stainless then not an issue.

Full fill slabs should really be of the water resisting type specially made for this purpose (even so, I would never like to use it) otherwise partially fill.

If your outside wall will be rendered or has another form of cladding then you don't need to be concerned. ditto if the area is sheltered from driving rain, for example if there is only a short gap between this wall and the neighbours house.