I'm about to install new skirting boards in a first floor bedroom that has recently been replastered (from bare brick or blockwork). The plasterer didn't go down very close to the floorboards and there is a gap up to 10 cm high in places where the bricks are visible behind. This gap is say 1.5 cm deep (the combined depth of the backing plaster and skim coat). Does this matter, and what is the best way to bridge that gap when installing skirting in front of it? Obviously I want the back of the skirting to be flush with the top of the plaster, not the underlying bricks. Do I just drill extra long screws into the bricks and allow part of the screw shafts to hang though the 1.5 cm air gap between the bricks and skirting?