Wall insulation - gap in cavity

Yorkie1

Once I have replaced my single glazed windows with DG, I have up till now intended to put cavity wall insulation into my mid-30s semi.

I have encountered a potential CWI difficulty in the outside wall and would value views on a) how much of a difficulty this may cause, and b) whether it is easily remediable.

The house originally had an external coal store, which the previous owner had bricked up in order to create an under-stair area for the washing machine. At the same time the gas meter was installed in the same space.

It is clear that only the external wall was bricked up. At the back of this understair area, there is only a single brick wall between the outside and the inside - thus no wholly enclosed space throughout the entire side of the house for CWI, so any insulation would end up falling down into this understair area without barriers to retain it, and insulation couldn't be added at ground level at all.

I've looked upwards through the gap at the top of the area, and there is a cavity wall going upwards - with a piece of wood jutting out into about half of the cavity:



There isn't enough room between the external wall and the gas pipes / wiring cables for a second wall to be created at the back of the understair area.

Is there any existing CWI material which is sufficiently thick so that it won't fall down the space between the outside wall and this piece of wood?

Assuming there isn't, would it be straightforward for another batten to be added to the existing piece of wood, to create a barrier to prevent insulation getting into this area?

If that other piece of wood was added, would I need to be careful about which insulating material was used?

Hope I've explained it clearly enough - no wonder there's a massive draught coming from that area. It's only a tongue and groove door on this side of it!

Thanks in advance

Yorkie1

Just wondering whether anyone had any comments on the viability of creating a complete barrier / base in the cavity wall above my understair area, and whether I'd need to be careful regarding which CWI material was then used to insulate the wall?

phill99

Just close the cavity off with timber and then get the CWI people to inject into the cavity. As long as the cavity is closed off (eg like a door frame, then whatever goes in the cavity won't come out.

Yorkie1

Many thanks Phill99. This is a huge learning curve!

goaliehammy

You could also get some kingspan insulation board to fix to the single wall. just cut out around the gas meter and clip to the wall. this will provide insulation to this area also and as phill99 said just close off the upper cavity.

Yorkie1

I love it when a plan starts to come together, thanks goaliehammy