On Saturday, 30 December 2017 22:13:06 UTC, Andrew Gabriel wrote:
In article ,
Brian Reay writes:
On 30/12/17 14:53, Roger Hayter wrote:
There are allegedly some dramatic damp problems due to fitting it in the
wrong sort of situation, or with the wrong sort of householder. In
Merthyr Tydfyl and points south especially, for some reason. I don't
know the truth of the matter.


Depends on the house etc.

Some houses, including ours, were build with it as standard. We've not
had a problem.

When it's installed during the build, it's normally held against
the inner skin, leaving an air gap against the outer skin, and
that prevents moisture wicking through.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

Drivel.
Full fill cavity wall "bats" are moisture repellent mineral wool.
As is the stuff blown into existing walls.
Damp patches can appear due to cement droppings on fishtail cavity wall ties.

Rigid insulation board is secured against the inner leaf with clips attached to the cavity wall ties during construction.