the door is on the 1st floor leading to an iron fire escape, the sill sits on brickwork and is wider than the actual door opening. my plan is to put dpc under the sill, but a chippie I know says we should then drill three holes through the top of the sill and screw the sill down, then countersink and mastic where the screw holes are, obviously this means screwing through the dpc, and the mastic will show through the stain on the sill. I would prefer to wedge the sill in, and cement and use frame sealant round the sill, any ideas would be greatly appreciated.
