My dining room extension is under construction. The builder has completed it except for decoration but due to a missing window sill I can still see the construction method of the wall. It appears to be
– a thin outer cladding of stonework to match the external appearance of the rest of the property
– a very small air gap or approx. 2cm (clogged with quite a bit of debris in between)
– an inner wall of single thickness blockwork
– inner plasterboard dry lining.
I am no building expert but I thought there had to be a layer of insulation in addition to the blockwork and that given the standard construction here this would normally be expanded foam or the like sandwiched between 2 layers of blockwork. Don’t building regs demand a good layer of insulation?
I am also concerned that the small gap between the outer skin of stone cladding and the blockwork needs to be completely free of debris bridging the gap so as to ensure no water transmission?
I want to challenge the builder on these points but would like some expert advice first so I can feel more confident on these points.