DR-05Fill the fixing line and holesFill each nail or screw hole and the shallow groove left by the rail. On solid brick or block, use a standard multi-purpose filler, building up deep holes in thin layers. On plasterboard, whether over timber studs, metal studs, or dot-and-dab, use a flexible filler, as rigid filler can crack when the board flexes. On lath and plaster, use a plaster-specific filler and press it in gently - don't overwork it, as vigorous filling can crack old brittle plaster. If a lath has broken or plaster has come away in a patch, cut a small offcut of plasterboard to fit, tape the joints with scrim tape, then cover with one or two thin coats of filler.