is the frame work being fastened to the wall? you could pack it off 20mm at that point. Or drill several holes in the timber where the air brick is. and just put a few extra fixings into the wall either side.
is the frame work being fastened to the wall? you could pack it off 20mm at that point. Or drill several holes in the timber where the air brick is. and just put a few extra fixings into the wall either side.