How to Fit a Door Leaf: Hang, Trim & Hinge (India 2026)

Learning how to fit a door properly is the difference between a leaf that swings silently and shuts with a soft click, and one that drags, springs open, or refuses to latch. Fitting a door slab (the bare leaf, hung on site) means trimming it down to the frame with even margins, planing a small bevel on the lock edge so it clears as it closes, cutting clean mortises for three hinges, hanging it, and then fine-tuning the swing and gaps. It is one of the most satisfying jobs on an Indian site — but also one of the easiest to ruin by over-trimming. This guide walks the full sequence from measuring the leaf against the door frame, through scribing and planing, to mortising the hinges and checking the final gaps, and is honest about where a DIY hand should stop and a skilled carpenter takes over.

Before you start: tools and the rules of thumb

Fitting a leaf is mostly about removing material slowly and checking often. You will want a tape, a sharp pencil, a try-square, a marking gauge, a sharp hand plane, a chisel set, a mallet, a drill, a screwdriver and a couple of wedges to hold the leaf in the opening. A power planer speeds the work but removes material fast — dangerous on a hollow flush door.

Three numbers govern the whole job:

• Margins: about 2-3mm on the hinge and lock stiles, and 2-3mm at the head.
• Maximum trim: never plane more than about 5-6mm off any one side, and split a wider reduction equally between the two stiles so the leaf stays centred and any lock mortise/panel layout stays balanced.
• Bottom undercut: 6-12mm over the finished floor — more for ventilation, less where a threshold or seal is fitted.

The leaf must already be the right basic size for the opening. If a 35-40mm-thick flush door has a solid lipping (the timber edge band) of only a few millimetres, you cannot plane far before you cut through the lipping into the hollow core — which is why over-trimming is the most common DIY failure.

How to fit a door, step by step

Work in this order; each step depends on the one before it.

The first two steps are not optional. If the frame itself is out of plumb or square, no amount of clever leaf-trimming will give an even gap — the door will bind at one corner and gape at another. Sort the frame first; see door frame plumb and level.

Measuring and scribing the leaf to the frame

Measure the opening width at the top, middle and bottom and the height at both jambs and the centre, and always work to the smallest dimension. Indian frames — especially site-built timber chowkhats — are rarely a perfect rectangle, so a leaf cut square to the largest reading will jam at the tightest point.

Offer the leaf into the opening, resting it on small wedges to hold it at the right bottom undercut, and pushed up against the hinge jamb. Now scribe: run a pencil or a scribing block along each jamb so the line on the leaf copies the exact shape of the frame, including any out-of-square. Mark the head the same way. Subtract the margin — about 2-3mm per side — from the scribe line; that final line is your plane-to line. Scribing copies the frame's real shape onto the leaf, which is why it beats simply measuring and cutting a rectangle.

Remember the maximum trim rule: if the leaf is much too wide, do not take it all off the lock stile. Split the reduction between both stiles so the leaf stays centred, keeps its factory lipping on both edges, and — on a panelled door — keeps the stiles looking even. Taking more than ~5-6mm from one edge of a flush door risks breaking through the lipping into the hollow core.

Planing the stiles and the lock-edge bevel

Plane down to your scribed line in long, even strokes, checking the fit by offering the leaf back into the opening repeatedly — it is far easier to remove a shaving more than to glue timber back on. Keep the plane square to the face on the hinge stile so the hinges seat flat.

The lock (closing) edge gets a slight bevel — about 2-3°, leaning so the face that meets the frame last is fractionally narrower. As a door swings shut it pivots on the hinges; the outer corner of the lock edge follows an arc and would catch the frame rebate if the edge were dead square. The bevel lets the leading edge swing clear into the rebate and close cleanly. It is subtle — a millimetre or two of lean across the thickness, not a chamfer you can see across the room.

Seal every planed edge afterwards: a bare timber edge wicks Indian humidity and swells, so prime and paint or polish the cut edges before the door goes into service. See door painting.

Marking and mortising the three hinges

Most interior leaves hang on three hinges, which resists warping better than two and spreads the load. Standard layout:

Hold the leaf in the opening against the hinge jamb and pencil the hinge positions across both the leaf and the frame together, so they align exactly. Set a marking gauge to the hinge-leaf width and depth and gauge the mortise (the recess) on the leaf edge. Chisel out the mortise to the depth of the hinge knuckle so the hinge sits flush — too deep and the door is "hinge-bound" and springs open; too shallow and the gap on the hinge side is too wide. Cut the matching mortises on the frame.

Fix the hinges to the leaf first, then offer it up and drive one screw per hinge into the frame. Test the swing and gaps before you drive the rest — a single screw is easy to back out and adjust. For hinge sizing on heavier leaves, the door hinge size calculator helps; replacing tired hinges is covered in door hinge replacement.

Fit detail: scribe line, lock bevel and hinge layout

Hanging, checking the swing and the gaps

With one screw per hinge driven, swing the leaf slowly and watch the whole arc, not just the shut position. Look for:

• Even reveal: the gap should be uniform — about 2-3mm — all round the head and both stiles. A wedge of gap that narrows toward one corner means the frame or the hinge depth is off.
• No drag: the leaf must not scrape the frame or floor anywhere through the swing. The high spot is usually mid-arc, not the closed position.
• No spring-open: if the door pushes itself open, a hinge mortise is cut too deep (hinge-bound). Pack a thin card shim behind that hinge leaf.
• Clean latch: the leaf should meet the door-stop evenly and the latch should align with the strike.

Only when the swing is true do you drive the remaining screws and fit the lock or latch (mortised at handle height, roughly 900-1050mm). For a deeper checklist of gaps and what each fault means, see door clearances and tolerances and the overall door fitting guide.

Planing the bottom for the undercut

The last cut is the bottom. With the door hung, scribe a line that gives the target undercut of 6-12mm over the finished floor — 10-12mm for carpet, return-air or bathroom ventilation, less where a threshold or seal is fitted. Always work to the finished floor, not the bare screed; if you cut to the screed and tile or marble goes down later, the door binds. On a hollow flush door, never cut past the solid bottom rail into the void. Take equal amounts if the floor slopes so the leaf bottom stays parallel, then seal the cut edge. The fine detail of this gap is covered in door undercut clearance.

When to call a carpenter

DIY hanging is realistic on a light internal flush leaf in a true frame. Call a skilled carpenter for heavy or solid timber leaves, out-of-square frames, double doors that must meet in the middle, fire-rated doors (which need tight ≤ 3mm gaps and certified hardware), and any leaf where the lock mortise and hinge layout must be cut to fine tolerance. A factory prehung unit — leaf already hung in its frame — sidesteps most of this; see prehung vs slab doors. To plan the whole job and avoid the classic errors, read the complete door guide and door installation mistakes, and estimate labour with the door fitting cost estimator.

Frequently asked questions

How much can I plane off a door to fit it?

As a rule of thumb, plane no more than about 5-6mm off any one side, and split a wider reduction equally between the two stiles so the leaf stays centred. On a hollow flush door you must stay within the solid timber lipping — cut into the hollow core and you expose the void and weaken the leaf. If the door is far too big, it is the wrong size for the opening.

Why does the lock edge of a door get a bevel?

As the door swings shut it pivots on the hinges, so the outer corner of the lock edge follows an arc. A square edge would catch the frame rebate; a slight 2-3° bevel, leaning so the leading face is fractionally narrower, lets the edge swing clear and close cleanly. It is a millimetre or two across the thickness, not a visible chamfer.

Where do the three hinges go on a door?

The top hinge sits about 200mm down from the top edge, the bottom hinge about 250mm up from the bottom edge, and the third hinge in the middle (or slightly above centre). Three hinges spread the load and resist warping better than two, which matters in India's humidity swings. Mark the leaf and frame together so they align exactly.

Why does my newly hung door spring open by itself?

That is "hinge-bound" — usually a hinge mortise cut too deep, so the hinge knuckles are pinched and force the leaf open. Pack a thin card shim behind that hinge leaf to bring it out, or if the gap is wrong on the hinge side the mortise may be too shallow. Check both hinge depths and the frame is plumb.

How big should the gap under the door be?

Leave a bottom undercut of 6-12mm over the finished floor — 10-12mm where the door must pass return air, sit over carpet, or ventilate a bathroom, and less where a threshold or seal closes the gap. Always measure to the finished floor, not the bare screed, or the door will drag once tile or marble is laid.

Should I fit a door slab myself or buy a prehung door?

A light internal flush leaf in a true frame is a realistic DIY job if you measure, scribe and trim patiently. A prehung unit comes with the leaf already hung true in its frame and is faster and more accurate, though dearer and less flexible. For heavy, solid, double or fire-rated doors, or an out-of-square opening, use a skilled carpenter.