What Is an Architrave?
An architrave is the decorative moulding that frames a door or window opening, covering the gap between the wall plaster and the door lining or window frame. Like skirting boards, architraves are typically made from MDF or timber and are available in a wide range of profiles — from classic Torus and Ogee to contemporary Square Edge.
Tools & Materials You'll Need
- Architrave lengths (allow 10–15% extra for waste)
- Mitre saw or mitre box and hand saw
- Tape measure and pencil
- Spirit level
- Coping saw (for internal corners)
- Nail gun or lost-head nails and hammer
- Wood adhesive / grab adhesive
- Decorator's caulk and caulk gun
- Sandpaper (120 and 180 grit)
- Primer and paint
Step 1: Measure the Door Opening
Measure the height of the door lining on both sides and the width across the top. Add a reveal margin — typically 6–8mm — which is the small step between the edge of the door lining and the face of the architrave. Mark this reveal consistently around the opening using a pencil and combination square.
Step 2: Cut the Vertical Legs
Cut the two vertical side pieces (legs) to length. The bottom of each leg sits on the floor or just above the skirting board, and the top is cut at a 45° mitre angle to meet the head piece. Mark and cut carefully — always cut slightly long first and test-fit before making the final cut.
Step 3: Cut the Head Piece
The horizontal head piece runs across the top of the door opening. Both ends are cut at 45° mitres to meet the legs. Measure between the outer edges of the reveal marks at the top of each leg to get the correct length. Cut the mitres so they angle outward from the centre.
Step 4: Test Fit Before Fixing
Dry-fit all three pieces together before applying any adhesive or nails. Check that the mitre joints are tight and the reveal is consistent. Make any fine adjustments with a block plane or sandpaper.
Step 5: Fix the Architraves
Apply a thin bead of wood adhesive to the back of each piece, then nail through the architrave into the door lining and into the wall stud or plasterboard behind. Use 40–50mm lost-head nails or a nail gun. Punch nail heads below the surface and fill with wood filler.
Step 6: Fill, Sand & Finish
Fill all nail holes and any small gaps at the mitre joints with flexible decorator's filler. Once dry, sand smooth with 180 grit paper. Run a fine bead of decorator's caulk along the back edge where the architrave meets the wall, and smooth with a damp finger. Prime any bare MDF edges before painting — two coats of a quality satin or gloss finish will give a professional result.
Tips for a Professional Finish
- Prime MDF end grain thoroughly — MDF absorbs paint heavily at cut ends, so apply two coats of primer before the topcoat.
- Use a consistent reveal — 6–8mm is standard; inconsistency is the most common cause of an amateurish result.
- Mitre joints on pre-primed MDF — apply a little wood glue to the mitre joint and clamp or tape while it sets for a tighter, more durable joint.
- Match your skirting profile — for a cohesive interior finish, choose an architrave profile that complements your skirting board.
Shop Architraves at Univers
We stock a full range of moisture-resistant MDF architraves in all the most popular profiles, available factory-primed and ready to paint. Order online with nationwide UK delivery, or visit our Gosport showroom to see the profiles in person.