Where the doors are to be located on a conservatory what do you do with the DPM/concrete over the cavity? I am currently up to damp course with a 75mm cavity and the conservatory frame will sit on the inside edge of the outer brick, do I need make sure that the DPM reaches the outer brick in this area or cut it back to cover the inner brick, Plus any advice on filling the base with concrete & screed/self levelling compound.