Door Stop Bead: Profiles, Fire-Door Specs, and How to Fit It

Your carpenter hangs eight internal doors over a long afternoon. Three close cleanly on the first try. The other five bind at the top, scrape on the strike side, or refuse to latch. The fix is the same in every case: the door stops were nailed to the linings before the doors were hung, and now the swing position doesn't match where someone guessed the stop should sit. Pulling the stops off without splitting them takes an hour per door. Fitting them in the right place takes ten minutes. Door stop beads are the cheapest piece of timber in any second-fix package, and they're the single most common reason new doors don't close properly.

What a door stop actually is (and what it isn't)

A door stop bead is the thin strip of timber, usually

, planted (nailed) to the inside of a door lining. The door closes against it. The stop sets the stopping point of the swing, holds the door flush with the frame, and creates the rebate that an intumescent strip sits in for fire doors.

This is not the floor-mounted rubber buffer that prevents a door handle hitting the wall behind it. That's a different product, often confusingly called a "door stop" in retail listings. The thing this page covers is the timber bead inside the door frame. If you're searching for a magnetic catch or a chrome cylinder that screws into your skirting, you're on the wrong page.

The reason domestic UK door linings have a separate planted stop (rather than a rebate machined into the lining itself) is practical. Premium frames have a moulded rebate where the door closes against an integral step. They're heavier, more expensive, and one-way only. A planted stop bead lets you choose the swing direction on site, adjust the stop position once the door is hung, and replace it cheaply if the door is ever swapped for one of a different thickness. Almost every internal door in a typical UK house uses a planted stop.

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Profiles and sizes

The cross-section dimensions you'll see in builders merchants are remarkably consistent. Three sizes cover almost every domestic application.

The edge detail on the front face is usually a slight 1.5mm radius (a softened arris) on primed MDF profiles, or a square edge on most solid timber. The radius is a paint-finish concern: a perfectly square edge is hard to keep paint built up on without it chipping. Either reads fine once installed.

Length matters less than profile size, but check it. Standard internal doors are 1981mm tall. Add the head piece across the top of the lining and you need around 2.4m of stop per door side, or 4.8m per door (one upright on each jamb plus one across the head). A 2.1m softwood length covers a single jamb with offcuts; a 2.4m length covers a jamb and gives you the head piece from the offcut. SAM04 primed MDF is sold in 5490mm lengths from trade merchants, which gives one full door (both jambs and the head) from a single length.

The 12mm vs 25mm fire-door confusion

This is the single most argued point in DIY forums about door stops, and it costs people money when they get it wrong.

The current rule for FD30 fire doors in domestic settings is straightforward. The planted stop must be a minimum of

, fixed with glue and 38-40mm steel pins, with intumescent strips fitted into a 15 x 4mm routed groove in the lining. That's the BS 8214:2016 specification, retained in the BS 8214:2026 update that came into force March 2026. Howdens FD30 installation instructions, BWF Fire Door Alliance guidance, and Certifire-certified door manufacturers all align on this.

The 25mm requirement that older guides still quote is a throwback to BS 476 Part 8 from the 1970s, which set out a prescriptive construction method before intumescent strips became standard. Once intumescent strips became part of the assembly, the deeper stop was no longer needed. There's even an argument, raised in expert forums, that the deeper stop can create a draw effect that increases cold smoke passage between the door and frame.

If your old door lining has a 25mm rebate or a 25mm stop, leave it. It's still compliant with current standards, just not the minimum any more. The confusion only matters when you're cutting a new lining or replacing an old stop bead for a fire door.

Why you fit the stop AFTER hanging the door

This is the rule almost nobody writing a DIY guide states clearly: the stop bead goes on after the door is hung, the latch is fitted, and the door swings cleanly. Not before.

The reason is simple. The stop position is determined by where the door actually closes, not where the lining was theoretically positioned. Linings twist. Walls aren't truly plumb. A door hung with the hinges on the right may sit 2mm differently from a door hung with hinges on the left, even in the same lining. Pre-cut linings supplied with the stop already housed in (rebated linings) work for some installations but not all, which is why most carpenters buy linings without the stop fitted and plant the bead on after hanging.

The professional sequence:

1. Lining first. Fit and pack the door lining during first-fix carpentry, before the plasterer arrives.
2. Plaster. The plasterer finishes flush to the lining face.
3. Hang the door. Cut hinge mortices, fit hinges, hang the door, fit the latch and strike plate, check the swing.
4. Mark the stop. Close the door fully. With the door held shut against the lining face, run a pencil line down the lining at the back face of the door. That line is exactly where the stop face needs to sit, minus the gap.
5. Plant the stop. Cut the stop pieces with mitred or butt joints at the head, hold them against the pencil line with plastic packers (1-2mm) maintaining the gap, and nail them through into the lining.

Skip step 3 and you're guessing. The forum complaint that comes up week after week ("my newly hung doors are hard to close that last bit") almost always traces back to the stop being fitted before the door was hung, with no allowance for the actual swing position or for paint build-up.

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The 1-2mm paint gap

This is the second rule almost no published guide explains: the stop face does not butt up against the door face. There has to be a small gap, typically 1-2mm.

The gap exists for two reasons. First, paint. When you decorate the door and the stop separately (which you will, because the stop face is on the lining and the door is a different surface), each gets its own coats of paint. Two coats either side of the joint can easily add up to 0.5-1mm of total paint thickness. Without a gap, the door starts binding the moment the paint cures.

Second, seasonal movement. Timber doors and timber stops both expand slightly in summer humidity and contract in winter dryness. A gap that's 0 in March is +1mm by August. A door fitted with no gap will rub for half the year.

The standard professional method: hold a 1-2mm plastic packer (some carpenters use a 2p coin, which is roughly 2mm thick) between the stop and the door face when nailing the stop into position. That sets the gap consistently around the entire frame. Other guides quote 3mm or "1/8 inch", which is a US-influenced figure and works on softwood doors, but feels excessive on a tight UK installation. 1-2mm is the right target.

Material choice

Three materials cover almost every job.

Softwood (redwood pine). The traditional choice. Takes paint adequately after priming and a careful sand. Strong enough to take the latch impact thousands of times without splitting. Repairable if a section gets damaged (you can sand and refill). Knots can bleed through paint if not sealed with a stain-blocking primer. The cheapest option.

Primed MDF (SAM04 profile). Smoother face, no grain, no knots, paints to a glassy finish with minimal prep. The trade standard for paint-grade work where consistency matters. Cannot be stained. There's no grain to show through, and the surface absorbs stain unevenly into a patchy mess. SAM04 is sold trade-counter at Travis Perkins and Jewson in long 5490mm lengths.

Hardwood (oak). For stain-grade or oiled finishes where you want real timber to show through. Available in solid oak (genuinely solid) or oak-veneered (a thin oak skin over softwood or MDF). Solid oak is what you want for a stairhead or a feature door where the trim is on display. Roughly three to four times the price of softwood for the same profile.

For fire doors, the wider 12 x 44mm profile is often specified because the extra width gives more substantial cover over the intumescent strip groove and makes the bead look proportionate to a heavier fire door leaf.

The decision rule is straightforward. Painted finish in a normal room: primed MDF. Painted finish on a budget: softwood. Stained or natural-finish door: solid oak (never MDF). Fire door FD30: primed MDF in 12 x 44mm with intumescent strip groove in the lining.

How to fit it

The tools are basic. A mitre saw or mitre box, lost-head nails (40mm for softwood, 38mm steel pins for fire doors per Howdens spec), a nail punch, a hammer or pin nailer, and a sharp pencil. A pin nailer is faster and reduces the splitting risk near edges, but hand-nailing with a 40mm lost-head pin is fine if you pre-drill or blunt the nail tip.

The fitting steps:

1. Mark the stop line. With the door hung, latch fitted, and door fully closed, run a pencil line down the inside of the lining where the back face of the door meets it. Repeat on the head and the hinge-side jamb. This is the line your stop will be set back from by the paint gap.

2. Cut the head piece first. Measure between the inside faces of the two jamb stops once you've held them dry-fit in place. Cut the head with 45-degree mitres at each end, or with butt joints if you prefer the simpler look. Mitres are cleaner once painted but take more skill; butt joints are forgiving and standard on jobs where speed matters.

3. Apply the head. Hold the head piece against the lining at the marked position with a 1-2mm packer between it and the door face. Nail through the stop into the lining head with two or three lost-head nails, evenly spaced. Punch the heads below the surface.

4. Cut and fit the jambs. Each jamb piece runs from the floor (or just clear of the floor finish if flooring isn't yet in) up to meet the head. Mitre the top to match the head, or square-cut for butt joints. Hold against the marked line with packers maintaining the gap, and nail through into the lining at 300-400mm spacing.

5. For fire doors only: apply a continuous bead of PVA or polyurethane glue to the back face of the stop before nailing, and use 38mm steel pins not lost-head brads. The BWF specification requires both glue and steel pins because the stop has to stay attached during a fire when timber connections fail.

6. Punch and fill. All nail heads punched 1-2mm below the surface. Fill with wood filler matched to the stop material (white filler for primed MDF, neutral for softwood that's going to be painted, beeswax-based stick filler for stained oak).

Mitre joints at the head

There are two ways to handle the corners at the top of the lining where the head piece meets each jamb. Both work. Pick one and be consistent.

Mitred joints are 45-degree cuts on both pieces meeting at a tight V at the corner. The cleaner option once painted. Harder to cut accurately because both faces of the joint have to match exactly, and any twist in the lining throws the angles off.

Butt joints are square cuts on the jamb pieces with the head piece sitting on top of them, or square cuts on the head with the jambs running up to meet it. Faster, more forgiving, slightly less polished. Acceptable on most domestic work and what most production builders use.

Mitre Mate or equivalent two-part adhesive (cyanoacrylate plus activator spray) bonds mitre joints in seconds and keeps them from opening over time. Worth using on visible mitres in higher-end work.

Replacing or repositioning a stop

Common scenario: you've replaced an old 44mm internal door with a slimmer 35mm leaf, and now there's a 9mm gap between the door face and the existing stop. The door rattles in its frame and won't latch cleanly. You need to move the stop forward by 9mm.

The technique:

1. Score the paint along the full length of the stop with a Stanley knife, both at the lining face and along the top edge. This stops paint tearing off the lining when you remove the stop.
2. Slide a wide chisel between the stop and the lining at the centre of the upright piece, not at the ends. Lever gently. The nails should pull out cleanly with the stop. Work along the length, repositioning the chisel every 200-300mm.
3. Pull old nails out of the back of the stop with pliers if they came out with it, or punch them through the lining if they stayed put.
4. Refit the stop in its new position using the close-the-door-and-mark technique. New nails into fresh lining timber, not into the old nail holes.
5. Fill the old nail holes in the lining with wood filler before redecorating.

Replacement stop laths are stocked at any builders merchant. If your existing stops are oak or stained softwood and you can't find a colour match, sometimes the easiest fix is to buy a full new set of stops in primed MDF and repaint the door frame to match. Mixing old and new stops on the same lining usually looks worse than starting fresh.

Common mistakes

Fitting the stop before hanging the door. The single most common failure. Pre-fitted stops force the door to close against a guessed position, which almost never matches where the door actually wants to sit. Fix: pull the stops off, hang the door properly, refit the stops.

No paint gap. New paint adds 0.5-1mm of thickness on each face. A stop fitted hard against the door binds the moment the paint cures. Fix: 1-2mm packer between stop and door face when nailing.

Wrong stop depth on a fire door. A 6mm or 9mm stop on an FD30 door doesn't give enough cover over the intumescent strip and won't pass building control inspection. Fix: minimum 12mm planted stop on any fire door, fixed with glue and 38mm steel pins per BWF guidance.

Nails not punched and filled. Visible nail heads on a painted door stop look like amateur work. Fix: nail punch all heads below the surface, fill with appropriate filler, sand flush before painting.

Mitre joints with gaps filled with caulk. Caulk in a mitre joint shrinks and the crack reappears within months. Fix: re-cut the mitre or use Mitre Mate to bond a tight joint. Caulk is for the wall-to-architrave junction, not for filling carpentry mistakes.

Using MDF stops where the door is being stained or oiled. MDF cannot be stained. The result is a door with stained timber faces and a primed white stop in the middle, which looks wrong and is hard to fix without replacing the stops. Fix: match material to finish from the start. Stain-grade door means stain-grade stop (oak or softwood, never MDF).

Where you'll need this

• Decoration - door stops are painted as part of the second-fix decoration package, after they're planted and filled
• Plastering - the plasterer finishes to the lining face; stops go on after plastering and after the door is hung

Door stops are part of the second-fix carpentry package on any extension, loft conversion, or renovation that involves fitting new internal doors. They're cheap, easy to overlook, and the most common reason newly hung doors don't close properly the first time.

Buying notes

For a typical extension with two or three new internal doors, you'll need around 5-6 metres of stop bead per door (two jambs of roughly 2m each plus a 1m head piece, with 10% added for offcuts). That's two to three lengths of 2.1m softwood per door, or one full 5490mm length of SAM04 primed MDF.

Wickes and Selco stock 12 x 32mm softwood and primed MDF in retail quantities. Travis Perkins and Jewson carry the 5490mm SAM04 trade lengths in primed MDF, and trade counter pricing is materially better than retail per metre. Worth the trip if you need more than one door's worth. Specialist hardwood merchants like Oak Store Direct sell solid oak stops by the 2.1m length.

For fire doors, buy a Howdens or similar Certifire-certified FD30 lining kit that comes with the stop bead supplied loose. The kit includes the right profile (usually 12 x 44mm primed MDF) and the lining is pre-grooved for the intumescent strip. Buying the components separately and trying to assemble a compliant fire door from scratch usually ends up failing inspection.