Cavity wall insulation

[patsparky]

Is it possible to have cavity wall insulation in rat trap bond brickwork? I have been told it wont flow into the cavity because of all the header bricks. I would dearly like my property to be insulated.

[kwicky]

choose your bond?

http://en.wikipedia.org/wiki/Brickwork

[buildersmate]

If you've been told this by a reputable cavity wall installer then I suspect that is it, because their installation process/method, as well as their materials, are closely controlled through something called an Agrement Certificate. This is set up to ensure that the installation will not result in unacceptable levels of dampness coming through the cavity wall. Whilst you do have a cavity wall it is partially compromised by the header bricks which bridge between the outer and inner skins. With air able to circulate in there, any dampness is partially able to evaporate up the cavity. With CW insulation the insulating material itself is impervious to damp penetration but the ability for water to bridge to the inner skin via the headers will be increased. I cannot say for definite that it cannot be done but you should be advised by the suppliers.