How Do I Hang a Door Properly? Step-by-Step Carpentry Guide

Summary

Hanging a door is the trade-test job of carpentry — every joiner is judged on whether they can hang a door square, gap-perfect, latching correctly, and not catching. It's also the most common call-back: a door that swings open by itself, won't latch shut, drags on the floor in winter when it didn't in summer, or has a 5mm gap at the head and 0mm at the latch. Every part of those failures comes down to the same skills: read the frame, plane the door true, set the hinges with care.

For a tradesperson, door hanging is also one of the most frequently quoted-and-misquoted jobs. "How long to hang a door?" The honest answer is 45 minutes for an internal door in a true frame, 2 hours when the frame is out of square (most are), and half a day when a customer has bought a door that's too small and you're rebuilding the frame.

This article covers the procedure for a standard internal door, the variations for external doors and fire doors, frame-fault diagnosis, hinge specification, and common mistakes.

Key Facts

• Standard UK internal door height — 1981mm (78") most common; 1981/1981mm height tolerances ±2mm
• Standard UK internal door widths — 457mm, 533mm, 610mm, 686mm, 762mm, 838mm (18", 21", 24", 27", 30", 33")
• External door standard — 1981 × 838 × 44mm thick (rebated or non-rebated frame)
• Fire door standard — FD30 (30-minute), FD60 (60-minute) — typically 44mm or 54mm thick. Heavier, requires CE-marked hinges with intumescent backing
• Clearance gap (internal door) — 2mm latch side, 2mm head, 3–4mm threshold (more for carpets)
• Clearance gap (fire door) — 3mm or less on all sides per BS 8214:2016 to maintain fire resistance
• Hinge count — 2 hinges for doors ≤25kg; 3 hinges for >25kg or any fire door
• Hinge position (rule of thirds) — top hinge 1/3 down from top edge; bottom hinge 1/3 up from bottom; centre hinge (when fitted) at exact centre
• Hinge size (internal door) — 75mm or 100mm × 75mm pressed steel or solid drawn brass
• Hinge size (external door) — 100mm × 75mm minimum, solid steel or brass
• Latch backset — 60mm standard internal (door-edge to handle centre); 76mm available for thicker doors
• Door swing direction — described as "left-hand" (hinges on left when viewed from the side it opens toward you) or "right-hand"
• Building Regulations Part B (Fire safety) — applies to fire doors in HMOs, flats, and protected escape routes

Quick Reference Table

Detailed Guidance

Step-by-step: hanging an internal door

1. Measure the frame opening. Note the height at both jambs and the centre, the width at top, middle, and bottom. Frames are rarely square — note the worst-case dimensions.

2. Identify door swing direction. Stand on the side the door opens TOWARDS you. Hinges go on the right = "right-hand"; on the left = "left-hand".

3. Position the door dry into the frame with wedges or door-bobs taking the weight. Mark the edges of the door where they need planing — 2mm clear of frame at top and latch side, 3–4mm at threshold.

4. Take the door out and plane to size. Use a sharp jack plane on the long edges (hinge and latch); a block plane on the top and bottom. Plane WITH the grain on each edge, alternating direction at the ends to avoid breaking out. Check edges remain square with a tri-square. Lightly chamfer the latch-side edge (the door must close into a frame stop without the corner catching).

5. Position door back in frame with wedges at the correct clearance gaps. Confirm a 2mm gap all round with a piece of card.

6. Mark hinge positions. Top hinge: 150–200mm from top edge (or 1/3 of door height). Bottom hinge: 200–250mm from bottom edge. Centre hinge (if used): centre of the door height.

7. Mark hinge depth on the door edge — use the hinge leaf as a template, scribe round it with a marking knife.

8. Chisel the hinge mortices to the depth of one hinge leaf thickness — typically 2–3mm. Pare clean and square. Test-fit the hinge — should sit flush with the door edge.

9. Pilot-drill and fix hinges to the door with the supplied screws.

10. Offer door into frame, screw the top hinge to the frame first (one screw only to test). Test the swing — door should sit at 2mm clearance all round.

11. Adjust if needed — either by deepening the door-side mortice (door is binding) or packing under the hinge (door is loose). Once correct, fix all remaining screws.

12. Mark and mortice for the latch. Standard 60mm backset internal. Chisel face-plate flush. Latch operates smoothly when door is closed.

13. Mark strike plate position by closing the door against the frame with the latch in. Mortice and fit strike plate. Adjust until door latches with a single firm push.

14. Fit handles, test multiple cycles, ease any binding. Clean up, sweep shavings, leave the customer's space the way you found it.

Fire door specifics

Fire doors (FD30, FD60) have stricter rules:

• Must be installed in a CERTIFIED frame, with the certificate retained.
• Three hinges minimum (some manufacturers specify three on FD30 even at lighter weights).
• Hinges must be CE-marked, fire-rated, with intumescent pads behind each leaf.
• Clearance ≤3mm on all sides.
• Intumescent strip on the door edge or frame rebate — must NOT be painted over.
• Smoke seals where smoke containment is specified (typically in HMOs).
• Self-closing device (mechanical closer) where the door is a fire/escape door.

A non-compliant fire door install can be deemed a Fire Safety Order breach and create liability for the installer, the building owner, and the eventual occupant.

External door specifics

• 3-hinge minimum. Use solid steel or solid brass hinges, not pressed steel (corrosion).
• Threshold weather seal required.
• Door must close against a continuous compression seal (or brush seal on a lower-spec installation).
• For PAS 24 security compliance, use Anti-snap euro cylinder, 3-star (TS 007) or Sold Secure SS312.
• New external doors in new builds must achieve a U-value ≤1.4 W/m²K per Part L1A.

Common faults and their causes

• Door swings open or shut on its own — frame is out of plumb. Use a level to check the hinge jamb; if more than 3mm off plumb, the door will gravitate. Shim hinges to compensate or re-fix frame.
• Door drags on threshold — clearance was set in summer with low timber moisture; in winter the timber expands. Plane more aggressively (3–4mm threshold clearance).
• Latch doesn't engage — strike plate is misaligned; door is sitting slightly low or high in frame; latch backset is wrong for the handle.
• Door binds on hinge side — hinge mortice is too shallow; hinge sits proud and door can't close. Deepen mortice.
• Door is gappy at the top — hinges are over-mortised; door is sitting too low in the frame. Pack out the bottom hinge slightly.

Frequently Asked Questions

How much should I quote for hanging one internal door?

A standard hang on a true frame, customer-supplied door: £80–120 + materials. If you're supplying the door, add £35–80 for a standard primed door. Out-of-square frames add 30–60 minutes; quote £150–180 for these. Fire doors add 30–60 minutes for compliance steps; quote £180–250.

Can I plane a fire door to fit?

Yes, but only within manufacturer's stated trimming allowance (typically 6mm off any edge, sometimes more from the bottom only). Trimming beyond the allowance voids the fire certification. Some doors are intumescent-stripped on the edge — never plane through the strip.

What's the best way to find out if a door is left- or right-handed?

Stand on the side the door OPENS TOWARDS you. If the hinges are on your right, it's right-handed; on your left, left-handed. UK convention. Always confirm with the customer before buying the door — wrong-handed doors are a common return.

Do I need to seal the door bottom for a carpeted threshold?

The customer's choice. Sealing a carpeted threshold prevents draughts at the cost of slightly stiff opening. Standard practice is to leave 8–10mm clearance for fitted carpets (clears underlay and pile), then no brush seal unless customer requests it.

Why does the latch only engage when I lift the handle?

The strike plate is sitting too low, or the door has dropped slightly. Lift the door by gripping the bottom of the hinge side and lifting — if the latch then engages clean, the hinge screws are loose or hinges are wearing. Re-fix with longer screws or replace hinges. If lifting doesn't help, the strike plate needs re-fixing higher.

Regulations & Standards

• BS 8214:2016 — Code of practice for fire door assemblies. Specifies installation, gaps, hardware, intumescent provision

• BS EN 1935:2002 — Building hardware – Single-axis hinges – Requirements and test methods. Used for fire-door hinge certification

• BS EN 12209:2016 — Building hardware – Locks and latches. Used for euro cylinder and mortice latch certification

• PAS 24:2022 — Enhanced security requirements for doorsets and windows. Required on new builds under Part Q

• Building Regulations Part B (Fire safety) — Volume 1 (dwellings) and Volume 2 (other buildings); covers fire door requirements

• Building Regulations Part Q (Security) — applies to new dwellings; mandates PAS 24 doorsets on accessible openings

• Regulatory Reform (Fire Safety) Order 2005 — applies to HMOs and commercial buildings; fire-door compliance is a "responsible person" duty

• BS 8214:2016 — Fire door assemblies code of practice — BSI

• Approved Document B: Fire safety — gov.uk

• Approved Document Q: Security – Dwellings — gov.uk

• Door and Hardware Federation: technical bulletins — DHF

• skirting architrave — finishing door architraves and skirtings

• fire door installation — fire-door specific install procedure

• door frame fitting — fitting a new frame from scratch

• competent person schemes list — Part Q self-certification routes