David J wrote:
Not quite diy, but does anyone have a view (positive or negative) on
modern cavity wall insulation with foam or granules.

I had a previous house done with insulation foam in the 1970s and I
had no problems at all - apart from giving myself a problem later when
trying to drop a TV cable between floors via the cavity. The foam
insulation reduced my annual heating bill by 25%, and soon paid for
itself.

At the time I remember a brief cancer scare in the newspapers about
homes treated with this foam - but that ultimately came to nothing.

I had assumed that my current house, built in 1997, would have had the
wall cavities filled with insulation slabs at the time of building -
but some recent drilling through the exterior walls confirms that I
was wrong about that. Maybe the current building regulations for
insulation were not in place in 1997.

David

Ours was done a couple of years back with some sort of blown fibre.

Previously had a house with granules that fell out all over the place.
Believe some now used stick together.

Foam did have a bad press because it did give off fumes which did cause
difficulties for some people. No idea whether this is still the case.

Choice may be affected by where you live. We are in a very dry part of
the country. If you live somewhere wetter the choice may be more
restricted.

Grants used to be available from councils or your power supplier.
Probably still the case.

Googling found me a lot of information.