Cavity Closures

[Richard Radford]

I'm currently building an extension. The cavity was 80mm but my brickie has partially closed the cavity at the windows and doors by turning the inside leaf outwards (hope that makes sense). The resulting gap is around 30mm. On advice from the Buildings Inspector I purchased some Dampcor (I think that's what it was called), which is effectively a length of dpc with polystyrene stuck to it.
How do I use this? I am presuming that the dampcor goes into the cavity with the dpc against the inside face of the outer leaf and the polystyrene facing the inside leaf. Not sure what is being achieved by doing this though? Please help. Want to fit my new windows tonight!

 

[masona]

See this. This is the nearest picture I can find you at the moment,the picture is okay but the dpc should continue to the outer wall ( L-shape).The idea is to stop the rain at the front of the brickwork penetrating into the second wall of the cavity.Found another picture here. If you can't make a L-shape then put the dpc on the side window frame first as well and don't forget to use sealant on the outside of the frame.

 

[Richard Radford]

Excellent. Got the picture now. Thanks very much