We are having it installed in our 1930's red brick semi soon. It has a
single story extension on the side, and during the survey I was told that
the portion of old exterior wall now enclosed by the extension will still
need drilling and filling. I don't see why as it's no longer outside and so
can't loose heat other than into the extension which is itself heated. If I
can get them to leave this wall then it would save a lot of cleaning up and
redecorating afterwards.

Any thoughts ? the filling will be blown fibre which is both sticky so it
stays in place and also treated against moisture.

--
Pete Cross

Pete Cross wrote:
We are having it installed in our 1930's red brick semi soon. It has a
single story extension on the side, and during the survey I was told
that the portion of old exterior wall now enclosed by the extension
will still need drilling and filling. I don't see why as it's no
longer outside and so can't loose heat other than into the extension
which is itself heated. If I can get them to leave this wall then it
would save a lot of cleaning up and redecorating afterwards.

Any thoughts ? the filling will be blown fibre which is both sticky
so it stays in place and also treated against moisture.

I've already replied to this once but you obviously can't see it:

As has been mentioned on this forum before (mainly by me) blown wool CWI has
to be a complete install, IE, right up to the roof, any voids in it cause
damp problems, even if these voids are now 'indoors'.
Yes, some builders put in a cavity tray in the house wall when building
extensions, but many do not, meaning that if they tried to fill the cavity
above the extension without filling below first, what's the insulation
supposed to sit on? - it can't float in mid cavity so it just falls down
leaving gaps all over the place.
They are not filling this portion of the wall as a way of saving heat, they
are filling it to prevent damp occuring in other parts of the house.
Our general modus operandi was to drill each hole carefully (with the place
dustsheeted up of course) and with an operative holding a shovel directly
below the drill bit, tight up to the wall...usually no more than 4 or 5
holes.
Each hole is then blown and then pointed up with sand/cement leaving it
slightly hollow for polyfilla, a final cleanup inside will leave no more
dust then you could fit on a teaspoon and 4 or 5 ten pence sized patches to
fill and paint.

As an aside the blown wool is not sticky, it resembles cotton wool and is
bone dry, although it is treated against moisture, this is done at
manufacturing stage and is odourless.

Phil L wrote:


I've already replied to this once but you obviously can't see it:

I can only see your 16:02 post. As I am experiencing similar problems to
the OP can you tell me which of your postings I have read please.

Dave