Things to think about it

Door sizes are standardised to the three most common widths, which are still exact in imperial terms: 2ft 3in (686mm), 2ft 6in (762mm) and 2ft 9in (838mm). If you have a non-standard doorway, you may need to have a new door specially made. Most off-the-shelf doors will be a very tight fit in a standard door frame, and therefore only need a small amount trimmed off their height and edges in order to fit them exactly.

There is usually a limit to how much you can trim a door (around 10mm in total), so check instructions before you start. You should always remove equal amounts from both sides of a door.

Changing internal doors will instantly revitalise a room, however, the job will be considerably easier if you use the same sized hinges as before, and can therefore use the same hinge positions that are already on the door frame. This is the technique shown in this leaflet. If the frame (door lining) is also new, simply measure off hinge positions on the lining also, and cut out using the same principles as shown for the door edge.

If you do not use the old hinge positions as guidelines for hanging a new door, the standard positioning for hinges on a door edge are 15cm down from the top and 22.5cm up from the bottom. For a heavy door, a third hinge can be placed equidistant between these two.

There are many ways to finish your new door, from paint, to the huge range of easy-toapply natural wood finishes that are now available.

Handles and latches are normally not included with an off-the-shelf door. This allows you to choose your preferred style.

Favourite handles may be reused on a new door, but make sure that the latch works smoothly. If it doesn't, they are inexpensive to replace. To remove an old door, you may need to use a screwdriver to loosen old paint around the hinges and in the slots of the screws. Use a hammer to tap the handle of the screwdriver with the slot end positioned on the screwheads. A couple of taps will usually break the paint seal and make unscrewing the screws possible.

The latch plate and doorstop (thin batten of wood inside the door frame that stops the door) may need slight adjustments when a new door is fitted. Much will depend on the new door being the same depth as the old, and whether you position the handle in the same position as for the old door.

Take care when using chisels, always follow three rules:

  1. Keep hands behind the cutting edge
  2. Chisel away from your body
  3. Always secure the timber you are working on with a clamp or vice

Fit an internal door


Remove the old door. Ideally, plan to keep the doorstop in the same place. This will generally work as long as the new door is the same depth as the old. For thicker doors, the doorstop position will have to be adjusted.


Allow for a 3mm gap between the hinged edge of the door and the lining. A butt hinge is ideal to measure this gap.


On the closing edge, measure for a 3mm gap. Draw a line on both sides of the door so you reduce both edges equally.


Lay the door on its sides and plane back to the pencil lines. Replace door and check 3mm gaps on both edges.


You also need a 3mm gap at the top and bottom of the door. Bear in mind the finished level of the floor.


Mark with pencil lines as before and plane off as required. When using the plane, work from the outer edge of the door inwards to prevent splitting the end grain. To remove more than a few millimetres, use a hand saw.


Reposition the newly planed door. Mark across from the exact position of the old hinges on the lining onto the new door edge.


Lay the door on its side and use the marks to position the hinges. Draw a line around them and mark hinge thickness on the front edge too.


Use a chisel to make two cuts at either end of the hinge position, allowing the chisel corner to cut slightly further than the line edge.


Carefully run a retractable knife along the long side of the pencil line between the two chiselled cuts, pressing firmly but evenly. Cut to hinge depth.


Remove the marked wood with a chisel. Make cuts across the grain every 5-10mm, so you do not split the wood, tapping in the chisel to hinge depth.


Gently use the chisel blade to remove the wood by tapping the chisel along the pencil line at the front edge of the door, at the depth of the hinge.


When you have removed wood from all hinge positions, hold each hinge in place, mark screw holes and pilot drill (2-3mm bit ideal). Secure all hinges.


Fit the other half of the hinge into existing hinge positions on the door lining and screw in place. You might need someone to hold the door.


Mark top, bottom and end of latch case onto door face – line up with existing strike plate on door frame.


Continue pencil lines across door edge and draw a vertical guideline through the middle of the horizontal lines.


Measure the latch length and also the distance from the latch end to the spindle centre and mark on door.


Select a flat bit that is slightly larger than the latch casing and mark the latch depth with tape.


Place the bit point on the vertical guide on the door edge and drill slowly to the required depth. Be precise.


At the marked off spindle position drill carefully into each door face taking care not to split the wood.


Push the latch into the hole and position precisely vertical. Draw a pencil line around the latch plate.


Remove the latch and chisel away the wood within the guidelines to the depth of the latch plate.


Push the latch into position, ensuring the latch plate sits snugly. Drill pilot holes for the screws and secure.


Insert the spindle through the latch. Long spindles may need cutting down with a junior hacksaw.


Position the handles on the spindle. Make sure they are precisely vertical and use an awl to mark fixing holes.


Fix handles in position with a hand-held screwdriver, as a drill/driver can slip and scratch the handle surfaces.


Close the door and check that the latch engages correctly with the strike plate on the door frame.


If the strike plate needs any slight adjustment, unscrew it, chisel out any wood as required and refix the plate.


If the door rattles, or does not close tightly against the doorstop, lever it off with a chisel and reposition it.


Before decoration, have one final check to ensure that the door closes neatly within the frame.