Gather your supplies
• Replacement 100mm solid brass hinges (3)
• 1-1.5mm plastic packers
Remove door from frame by supporting door on wedges and removing hinge screws. Finish with top hinge, so the door won’t fall on you.
Place door in door stands. These are a pair of 600- to 900mm- long pieces of 70 x 35mm softwood with a notch cut out of centre, and a wedge driven in to hold door.
Remove old hinges and try to find replacement hinges that are same size and have same screw hole pattern. Even if old screw holes are stripped, they can be filled and reused.
Measure out for third hinge in middle. Hold hinge in place with back of leaf on edge of door and mark around using a sharp pencil.
Cut along outside of hinge using a utility knife to cut paint neatly.
Chisel out a housing for central hinge. It should finish flush with door edge. Depth will vary depending on hinge used. When chiselling at top and bottom of housing, hold chisel a fraction of a millimetre inside marked line, so when you tap chisel, the bevel on other side will push chisel right onto the line.
Plug old hinge screw holes by gluing matchsticks or other soft timber into holes. In most cases, you can hold 3 matches at entrance to hole and tap them in. When they can
go no further, they will snap off.
As door needs to be packed out at bottom and recessed at top to tilt it slightly, make adjustments on door. Chisel out an extra 1 or 2mm at top of door so that hinge sits below surface of door edge.
Predrill, then screw on new hinges. The top will be slightly recessed and centre hinge flush. Use 1-1.5mm packers, cut to suit, to pad out bottom hinge and raise it a little.
Measure distance from top hinge to centre hinge, then mark and cut a housing in door jamb to match hinge spacing on door. Plug old screw holes.
Stand door back on wedges at front and back and adjust so height is right. Then drive in one screw in top hinge and one in bottom. If bottom hinge is a little deep, you may need to add more packers. Test swing of door, then fit remaining screws.