closing cavity at the windows

[cw2p]

Hi all. Has the cavity to be closed on the vertical sides of the window ope with an L block or some other block in a standard cavity build or can the insulation be left out to the edge touching to the newly installed window. What is the idea of closing the cavity here anyway?

 

[sydthebeat]

the idea of closing the cavity is to add structural stability, but in most cases its fine not to. i generally specify that the gap between the outer and inner block be filled with insulation anyway, i dont trust the 25mm stuff that some builders include. Do not forget the DPC!!

 

[joker538]

The vertical cavity should be closed in cavity wall with an L-block, strip of 100mm wide vertical dpc and 25mm insulation. The L-block does be built on the internal face to external face. That would be the standard detail for an external cavity wall