Architrave: Profiles, Fitting, and What to Buy

You've painted the hallway. It looks good. Then you look at the doorway and there's a ragged gap between the door frame and the plaster, full of dry filler that's already cracking. Your plasterer finished three weeks ago and no one's fitted the architrave. Now the decorator has to work around exposed edges, the filler is pulling away from the plaster, and fixing it means stripping back paint you've already paid for. That strip of moulding around the door costs a few pounds per metre. Leaving it until last costs a lot more.

What it is and what it's for

Architrave is the decorative moulding fitted around door and window openings. Its job is simple: cover the joint between the door lining (the timber frame inside the wall) and the plastered wall surface. Without it, you'd see a rough gap where the plaster meets the frame. That gap is ugly, it collects dust, and the filler used to bridge it cracks within months as the building settles.

Every internal door in a typical UK house has architrave on both sides. It's one of those details that's invisible when it's done well and immediately obvious when it's missing or poorly fitted. The key rule is that your architrave profile should match your skirting board profile throughout the room. Ogee architrave with torus skirting looks wrong. It's a small detail that decorators and estate agents notice.

Architrave sits in the second-fix stage of a build. It goes on after the plastering is fully dry, after the door linings are set and the doors are hung, but before skirting boards. Get the sequence wrong and you'll be cutting around obstacles that shouldn't be there.

Profiles and what they look like

The profile is the shape of the moulding when you look at it end-on. Six profiles cover 95% of what you'll find in UK houses and builders merchants.

If you're extending a house built before 1940, the existing rooms almost certainly have ogee or torus mouldings. Match them. Specialist moulding suppliers (Skirting 4 U, National Skirting, Skirting World) carry period profiles that major retailers don't stock, and they'll send samples so you can check the match against your existing skirting before ordering.

For a new extension where you're fitting fresh skirting and architrave throughout, bullnose is the safest choice. It's available from every supplier, every retailer, and every builders merchant.

Sizes: width, thickness, and what looks right

Standard architrave widths in the UK are 44mm, 69mm, 96mm, and 121mm. The 69mm (sometimes listed as 70mm) is by far the most common in British homes and the right choice for most projects.

Width should be proportional to your skirting board height:

• 69-70mm architrave suits skirting up to 150mm tall. This covers the vast majority of UK houses.
• 96mm architrave suits skirting between 170mm and 195mm. You'll see this in houses with taller rooms and more generous proportions.
• 121mm architrave suits skirting 220mm and above. Period properties with very high ceilings and grand proportions.

Thickness is measured from the wall outward. Standard options are 15mm, 18mm, and 25mm. 18mm is the norm. Go thinner only if you're tight on clearance (rarely an issue); go thicker only for a deliberate chunky aesthetic in a period renovation.

MDF or softwood?

This is the first decision most people get stuck on. Both work. The choice comes down to finish, budget, and how much prep you want to do.

MDF architrave has a perfectly smooth face with no grain or knots. It takes paint beautifully and produces a consistent, factory-smooth finish. Pre-primed MDF architrave is available from most suppliers, which saves the most laborious prep steps. The downside: MDF cannot be stained (there's no grain to show), it's heavier than pine, and it swells if it gets wet. For a painted finish in any dry room, MDF is the practical choice.

Softwood (pine) architrave has visible grain and a natural timber feel. It can be stained, oiled, waxed, or painted. Pine is lighter to handle and less prone to moisture damage than standard MDF, though it still needs priming and painting in most installations. Knots can bleed through paint if not sealed with a stain-blocking primer. Pine architrave is comparable in price to primed MDF at the standard 69mm width.

For most extension and renovation projects where the architrave will be painted white or a neutral colour, primed MDF is the right choice. It's smoother, requires less prep, and the finish is more consistent.

How to work with it

The reveal

The reveal is the narrow strip of door lining visible between the inner edge of the lining and the architrave. Professional carpenters leave a 5-8mm reveal rather than fitting the architrave flush against the inner edge of the frame. There are two reasons: it creates a clean shadow line that looks deliberate, and it avoids the architrave fouling on hinges or the striker plate (the metal plate where the latch engages).

Click to enlarge

Mark the reveal consistently around the entire frame before cutting anything. The professional method: cut a small block of scrap timber or MDF to exactly 6mm and use it as a gauge. Hold it against the inner edge of the lining and draw a pencil line along its outer edge, all the way around the opening. A combination square set to 6mm works too. This takes two minutes and prevents the uneven reveals that make amateur work obvious.

Cutting mitres

The three pieces of architrave around a door (two vertical legs and one horizontal head) meet at 45-degree mitre joints in the top corners. Getting these mitres tight is the most visible test of the work.

A mitre saw is the right tool. A decent entry-level model costs £80 – £150; a mid-range saw from Makita, Evolution, or DeWalt costs £150 – £250. If you're fitting architrave throughout a house, it pays for itself in time and accuracy. A mitre box with a fine-toothed tenon saw works for a few doors, but accuracy depends on the saw tracking cleanly in the box. Cheap mitre saws with loose pivots produce poor cuts. A solid mid-range mitre saw (Makita, Evolution, or Dewalt) with a 210mm or 216mm blade is money well spent.

Here's what experienced carpenters know: door frames are almost never perfectly square. The lining twists, the reveals don't run parallel, and the corners rarely meet at exact right angles. This is normal. Don't assume 45 degrees is the correct angle for every joint.

Use a sliding bevel to capture the actual angle at each corner. Set the bevel to the corner angle, halve it for the mitre cut, and cut each piece to match its specific corner. Each end of the head piece may need a slightly different angle. Test-fit before nailing.

Fitting sequence

1. Mark your reveal lines around the entire opening using your gauge block.
2. Measure and cut the first vertical leg. Stand it in position dry (no fixings) and check it against the reveal line. The bottom sits on the floor (or on top of where the skirting board will go, if you're fitting skirting first, but normally architrave goes on before skirting).
3. Measure and cut the second vertical leg. Stand both legs in position.
4. Measure the head piece between the outer edges of the two legs. Cut both mitres. This is the critical piece. If the mitres don't meet tightly, re-cut rather than filling the gap.
5. Fix the legs first. Apply a bead of grab adhesive (Gripfill or similar) to the back surface, position against the reveal line, and nail through the architrave into the door lining with 38-50mm lost-head nails. Six nails per upright, spaced evenly. Use a nail gun if you have one.
6. Fix the head piece. Apply adhesive and nail in place. Drive a nail through the mitre joint itself (downward through the head into each leg) to lock the joint.
7. Punch all nail heads below the surface with a nail punch. Fill with wood filler.

Dealing with proud plaster

This is the single most common real-world problem with architrave fitting, and no mainstream guide explains it well. After a new extension is plastered, the plaster skim coat frequently sits slightly proud of (higher than) the door lining surface. When this happens, the architrave can't sit flat against both the lining and the wall. It rocks.

The standard fix: score around the perimeter of the door lining with a sharp utility knife, cutting through the plaster along the edge. Then use a bolster chisel and club hammer to carefully chop back the proud plaster to just below the lining surface. Work carefully. You only need to remove material within the area that the architrave will cover. Don't dig beyond that zone.

An alternative (preferred by experienced joiners for a cleaner result) is to remove the door lining, trim it to match the new plaster depth, and refit it. This is more work but avoids any risk of damaging the plaster finish.

Gluing mitre joints

Nails hold the architrave to the frame. But the mitre joint itself benefits from adhesive, especially as timber shrinks seasonally and MDF can move slightly with humidity changes.

Professional second-fix carpenters use Mitre Mate (or equivalent brands: Everbuild Mitre Fast, Geocel Joiners Mate). It's a two-part system: a cyanoacrylate glue (superglue) applied to one face of the joint, and an activator spray on the other. When the two faces meet, the joint bonds in about ten seconds. It's strong, it doesn't move, and it stops the mitre from opening over time. A kit costs £8 – £12 and lasts for dozens of joints.

PVA on the mitre faces is the traditional alternative. It works, but it needs clamping pressure while it dries, which is awkward on an installed architrave. Mitre Mate is faster and more practical for on-wall work.

How much do you need

A standard UK internal door opening is 2040mm tall and 826mm wide (or 926mm for wider doors). One side of one door needs two vertical legs and one horizontal head.

The quantities work out simply:

• Each vertical leg: 2040mm plus the reveal (6mm top) minus whatever sits behind the skirting at the bottom. In practice, buy 2.1m lengths (the standard sold length) and trim to fit.
• Head piece: door width (826mm) plus two reveals (12mm) plus two architrave widths (138mm for 69mm on each side). Roughly 1000mm. One 2.1m length covers two head pieces.
• Per door, one side: 2 legs + half a length for the head = 2.5 standard lengths.
• Per door, both sides: 5 lengths of 2.1m. Some suppliers sell "architrave sets" (2 x 2.4m lengths for legs + 1 x 1.2m for the head) which is one side of one door for about 6 linear metres.

For a typical three-bedroom house with 8 internal doors, fitting both sides of every door: 8 doors x 2 sides x 5.2m per side = 83.2 linear metres. Add 10% for waste (mitre cuts, mistakes, off-cuts too short to use) and you need about 92 metres. That's 44 lengths of 2.1m.

Cost and where to buy

MDF primed architrave at the standard 69mm width is the volume product. This is what most builders merchants and DIY stores sell the most of, and where pricing is most competitive.

That range covers primed MDF in the main profiles (bullnose, ogee, torus, chamfered) from Wickes and Screwfix as of March 2026. Wickes bullnose is at the lower end (£4.05/m); torus and ogee profiles cost slightly more (£5.24/m). Screwfix sells five-packs of 2.1m lengths at roughly £4.76/m, which works out cheaper per metre than buying singles.

Softwood (pine) architrave in 69mm costs £3 – £5 per metre from Wickes. Bullnose pine is around £3.05/m. Torus pine is around £5/m. Pine is slightly cheaper at the budget end but slightly more expensive in the premium profiles.

Narrow 44mm architrave (for compact spaces or simple detailing) starts around £3 – £4/m in MDF and a similar range in pine.

Fully finished MDF (pre-primed and pre-painted white, ready to install with no further painting) costs £5 – £6/m. Wickes sells torus fully finished at £5.71/m and chamfered fully finished at £4.57/m. The premium over standard primed is modest, and it saves two coats of paint plus drying time.

For a whole house (8 doors, both sides, approximately 92 linear metres), material cost at the mid-range is roughly £400 – £480 in primed MDF. Fully finished MDF saves on paint but pushes materials to around £450 – £530.

Where to buy

Wickes and Screwfix stock the widest range of profiles in both MDF and softwood. Wickes carries bullnose, ogee, torus, and chamfered in 69mm MDF primed, plus pine equivalents. Screwfix sells multi-packs (5 x 2.1m lengths) which bring the per-metre price down.

B&Q carries a smaller range, mostly MDF.

Specialist moulding suppliers (Skirting 4 U, National Skirting, Skirting World, MDF Skirting World) offer a much wider profile range, including period patterns that major retailers don't carry. They also offer custom matching if you send them a profile sample. Prices are competitive with retail for standard profiles and cheaper for large orders. Delivery is typically £6 – £15.

Travis Perkins and Jewson stock architrave in trade quantities. If you're ordering alongside other timber and materials for a build, adding architrave to a trade order often gets it delivered free as part of a larger drop.

Alternatives

For most houses, architrave is the standard and correct finish. But two alternatives exist.

Shadow gap detail is the modern, minimalist alternative. Instead of a moulding covering the joint, a narrow gap (typically 10-15mm) is left between the door lining and the plaster edge, creating a deliberate shadow line. It looks clean in contemporary interiors. But it requires planning from the start: plasterboard edge bead must be fitted to the wall before boarding and skimming. You cannot just omit the architrave after plastering and call it a shadow gap. The plaster will crack at the junction, repeatedly. Shadow gap installation costs more than architrave because it requires more careful plasterboard detailing. It suits new builds and major renovations where the walls are being boarded from scratch.

Painting the lining edge with no trim at all is occasionally attempted. It looks unfinished. The crack between plaster and frame will reappear within a few months, especially in a new build where the structure is still settling. Not recommended.

Where you'll need this

• Decoration - fitted around all door and window openings after plastering, as part of the second-fix joinery package
• Kitchen installation - around any new doorways created or modified during the extension

Architrave is needed in every room of any extension or renovation project that has internal doors or new window openings. It's a small material cost relative to the overall build, but it's the kind of detail that pulls a room together visually and distinguishes a finished space from a building site.

Common mistakes

Mismatched profiles. Ogee architrave with torus skirting in the same room looks wrong. Always buy the same profile for both, in the same width. Check your existing mouldings if you're matching into an older house, and order samples before committing.

Poor mitres that get filled rather than re-cut. A gappy mitre joint filled with caulk or filler is visible after painting. The filler shrinks, the crack reappears. If the mitre isn't tight, re-cut it. Mitre Mate in the joint prevents it opening later.

No reveal on the door lining. Fitting architrave flush with the inner edge of the frame means it fouls on hinges and striker plates, and there's no clean shadow line. Leave 5-8mm. Mark it consistently with a gauge block, not by eye.

Not acclimatising MDF architrave. MDF delivered from a cold warehouse and nailed straight into a heated room will shrink as it adjusts to the indoor humidity. The mitres open up, gaps appear at the wall joint. Leave the material in the room where it'll be fitted for at least 24-48 hours before installation.

Fitting skirting before architrave. The standard sequence is architrave first, skirting second. The skirting butts up against the bottom of the architrave leg. If you fit skirting first, the architrave has to sit on top of it, which looks clumsy and creates an unnecessary junction that's hard to seal cleanly.

Painting MDF architrave

If you've bought primed MDF (which you should), the prep work is already half done. But the edges still need attention. Any cut edge exposes raw MDF fibre that absorbs paint differently from the primed face. Seal cut edges with acrylic primer or diluted PVA before your first topcoat. Two thin coats of satinwood or eggshell, sanding lightly with 220-grit between coats, gives a durable finish. Caulk the gap between the architrave and the wall with acrylic caulk (not silicone, which can't be painted) before the final topcoat for a clean, professional line.