What gap should I leave around a door?

Allow a 2-3 mm gap on the hinge side and lock side, and a 2-3 mm gap at the top. At the bottom, allow 8-10 mm for carpet, or 3-5 mm for hard flooring. These gaps ensure the door swings freely without binding. For fire doors, the maximum gap is 3 mm on all edges (4 mm at the bottom with an intumescent seal).

Where should door hinges be positioned?

For a standard internal door, position the top hinge 150 mm from the top of the door and the bottom hinge 225 mm from the bottom. If using three hinges (recommended for heavy or fire doors), place the middle hinge centrally between the other two, or slightly above centre. Use 100 mm (4-inch) butt hinges for standard doors.

How do I trim a door to fit?

Mark the cutting line with a pencil and straight edge. For small amounts (up to 5 mm), use a hand plane or belt sander. For larger cuts, use a circular saw with a guide rail or a track saw. Always score the cut line with a Stanley knife first to prevent splintering. Remove equal amounts from both sides if possible.

What size latch do I need?

Standard internal doors use a 64 mm (2.5-inch) tubular latch. For thicker doors (44 mm+), use a 76 mm (3-inch) latch. The backset (distance from door edge to spindle centre) is typically 44 mm for a 64 mm latch. Bathroom locks use a similar body but with a thumbturn mechanism instead of a key.

Can I hang a door on my own?

Yes, but it is much easier with a helper or a door hanging tool/wedge. A door lifter wedge (around £5) lets you adjust the door height with your foot while marking hinge positions. Alternatively, rest the door on a thin packer while you work. A door hanging typically takes 1-2 hours for a competent DIYer.

How to Hang a Door

Tools and Materials

Tools Required

Tape measure and pencil
Hand plane or belt sander
Circular saw (for large cuts)
Sharp chisel (25 mm and 38 mm)
Mallet
Drill/driver with pilot drill bits
Spirit level
Door lifter wedge
Stanley knife

Materials Required

Internal door (standard 1981 x 762 mm or measured to fit)
3 x 100 mm butt hinges (with screws)
Tubular latch (64 mm or 76 mm)
Door handles (lever on rose or backplate)
Packing shims (if frame is out of plumb)

Before You Start

Measure the opening at three points (top, middle, bottom) for width, and both sides for height — use the smallest measurements
Check the frame is plumb and square using a spirit level and tape diagonal measurements
If replacing a door, remove the old door and check hinge recesses — you may be able to reuse them
Allow the new door to acclimatise indoors for 48 hours before fitting to prevent warping
Prime or seal all six faces of the door (including top and bottom edges) to prevent moisture absorption

Step-by-Step Installation

Step 1 — Measure and mark. Measure the opening and transfer dimensions to the door, allowing for gaps (2-3 mm sides and top, 8-10 mm bottom). Mark the cutting lines clearly.
Step 2 — Trim the door to fit. Trim with a plane for small amounts or a circular saw for larger cuts. Score the cut line with a knife first. Test-fit the door in the opening with packers at the bottom.
Step 3 — Mark hinge positions. With the door wedged in the opening at the correct height, mark the hinge positions on both the door and the frame simultaneously. Top hinge: 150 mm from top. Bottom hinge: 225 mm from bottom.
Step 4 — Cut hinge recesses. Using a sharp chisel and mallet, cut the hinge recesses to the exact depth of the hinge leaf (typically 2-3 mm). Score the outline with a knife first, then chisel out the waste. The hinge should sit flush with the surface.
Step 5 — Fit hinges to the door. Screw the hinges to the door first, using pilot holes to prevent splitting. Check that the hinges sit flat and flush in their recesses.
Step 6 — Hang the door. With a helper or door lifter, position the door in the frame and drive one screw into each hinge on the frame side. Check the gaps and swing. Adjust if needed, then drive the remaining screws.
Step 7 — Fit the latch. Mark the latch position (typically at handle height, 1000 mm from the floor). Drill the latch bore hole through the edge, then chisel a recess for the faceplate. Insert the latch and screw the faceplate flush.
Step 8 — Fit handles and strike plate. Drill the spindle hole through the face of the door. Fit the handles on both sides. Close the door and mark where the latch meets the frame. Chisel a recess for the strike plate and fit it with screws.
Step 9 — Final adjustments. Check the door opens, closes, and latches smoothly. Adjust hinges or plane edges as needed. Apply a final coat of paint or stain to any exposed timber.

Common Mistakes

Not checking the frame is square — a twisted frame will cause the door to bind or swing open
Cutting hinge recesses too deep — the door will bind on the hinge side; pack with card if too deep
Splitting the timber by not drilling pilot holes — always pre-drill, especially near edges
Removing too much from one edge — trim equally from both sides where possible
Not sealing the top and bottom edges — moisture ingress causes warping

Cost Estimate (2026)

Item	Typical Cost
Internal door (hollow core)	£30-60
Internal door (solid core / panelled)	£60-200
Butt hinges (pair of 3)	£5-15
Tubular latch	£3-8
Door handles (pair)	£10-50
Total (standard internal door, DIY)	£50-280

Related Calculators

Use the Door Hanging Calculator for material lists, and the Door Lining Calculator if you need to install a new frame.