Is It Worth Insulating This Gap?

[thomp1983]

Hi all,

When we had our extension built part of the top of original outer cavity wall was removed as pictured,

This wall is now internal inside my double garage, as you can see the top 4 courses were removed, I'd like to keep the gap as my ladders fit up there nicely out the way, what I'm wondering though is, is it worth sticking 100mm celotex to the inner blockwork, this will a) cover the original cavity in the brickwork and b) hopefully help insulate the inner wall as the garage is cold compared to the rest of the house as you'd expect due to the doors not being fully sealed.

Thanks
Chris

 

[^woody^]

I can't see it making any difference and with a payback period running into centuries if at all calculable.

 

[thomp1983]

There's no real cost, I've loads of celotex off cuts I can use for it but like you I didn't know if it would actually make a difference