"alan_m" wrote in message
...
On 19/02/2020 08:21, Brian Reay wrote:
Brian Gaff \(Sofa 2\) wrote:
How would they get the existing stuff out? That might be an interesting
answer, involving taking the house apart perhaps.
I have no cavity walls, but still get leaflets through the door about
it
and wonder at the waste of rain forest and printers costs at delivering
them to houses they cannot fit it to. maybe they will built me a new
house?
grin.
Brian


They dont. If the slab stuff has gaps, they can ( in theory) inject the
foam stuff to fill them. Ive heard of it once, how effective it was/is I
dont know.

How would they establish if the existing cavity wall insulation has gaps?

By using an IR camera outside the house in
winter with the house heating turned up full.