How to Fit a New or Replacement Door
There is quite a lot to do when fitting a new or replacement door – even if it is the right size. You will need to fit the hinges to the door, together with some form of latch and may need to cut new recesses in the frame for the hinges and striking plate. If the door latch has a lock, you will need to drill and chisel out keyholes.
Doors come in standard sizes, but you may need to trim the sides of a door with a plane or the ends with a saw before fitting it. There needs to be around 3mm clearance at the sides and top, and 5mm at the bottom. Always take equal amounts off each side or end, and if planing the top and bottom, work from the edges toward the centre to prevent the wood splitting.
A solid hardwood external door will need three substantial hinges: typically 100mm (4in),but most internal doors can be hung on two 75mm (3in) hinges. If you are using brass hinges, always use brass screws.
Choose the hinge positions, using an existing door as a guide – some hollow flush doors incorporate hinge blocks of solid wood – and mark lines across the edge of the door with the aid of a try square. Then use either a hinge or a marking gauge set to the width of the hinge to mark out the recesses – each hinge should end up so that only the knuckle protrudes from the edge of the door. Also mark the thickness on the face of the door.
Cut out the recesses with a mallet and chisel, first cutting down along the lines with the chisel held vertically, then removing the wood with the chisel held at an angle, bevel down to prevent digging in. Take great care not to go beyond the marked recesses. When the hinges fit snugly, make pilot holes for the screws with a small drill or bradawl and screw the hinges in place.
Offer the door up to the frame, propping it on 5mm blocks, and transfer the positions of the hinges on to the frame. Cut the recesses in the same way, check the fit, make pilot holes and, with the door propped on the blocks again, secure the hinges to the frame. Check that the door swings freely and closes properly without catching the frame. If necessary, remove the door and deepen the hinge recesses, or pack them out with cardboard.
This needs only a large rectangular hole and two smaller holes to fit it. Mark out the position of these on the door – in a solid central rail or bottom rail or, possibly, vertically on the closing stile. Drill the two small holes (for the letter plate securing bolts) and drill largish holes at each corner of the main outline to start the jigsaw (saber saw). Cut along the marked lines, working from the outside of the door, so that any splintering is covered by the letter plate. Do not force the saw or its blade will bend. Clean up the hole with a file and fit the letter plate.