Second-fix carpentry is the visible finishing timber installed once the walls are plastered and the rough structural work is done. It covers the things you actually see and touch in a finished room: skirting boards, architraves, doors and their trim, plus any decorative mouldings. By contrast, first-fix carpentry is the hidden framework — joists, studwork, floor decking and door linings — fitted before the plaster goes on. Second-fix is where a room stops looking like a building site and starts looking finished.
What does second-fix carpentry include?
Second-fix work is the precise, neat, visible stage of the job. The structural carpentry holds the building together; second-fix makes it look intentional. A carpenter at this stage is working to fine tolerances, because every gap and joint will be on show once the room is decorated.
The typical scope includes:
- Hanging doors — fitting internal doors into their linings, planing them to fit, and adding hinges, latches and handles.
- Skirting boards — the timber that runs along the bottom of the wall where it meets the floor.
- Architraves — the moulded trim that frames a door or window opening.
- Window boards and sills — the internal shelf beneath a window.
- Mouldings — decorative features such as picture rails, dado rails and cornicing where these are timber rather than plaster.
- Built-in joinery — fitted wardrobes, shelving, airing cupboards and boxing-in for pipes.
- Stair finishing — handrails, balustrades and newel posts, depending on the build.
- Ironmongery — the catch-all term for handles, locks, latches and hinges fitted at this stage.
The defining feature is that all of this happens late in the build, after the messy trades have finished. A carpenter doing second-fix usually arrives once plastering is dry, walls are ready and the floor is protected. The work is measured in millimetres of fit and tidiness of joint rather than load-bearing strength.
Skirting, architrave and decorative mouldings
Second-fix carpentry is the visible finishing timber installed once the walls are plastered and the rough structural work is done.
Skirting boards do a practical job and a decorative one. They cover the junction between wall and floor — a gap that is rarely perfectly straight — and they protect the bottom of the wall from knocks, vacuum cleaners and furniture. They also set the character of a room. A tall, ornate Victorian-style skirting reads very differently from a slim, square modern profile.
Profiles are the shaped patterns milled into the timber. Common skirting profiles include ogee, torus, chamfered and bullnose, each describing the curve or bevel along the top edge. Architraves follow the same logic: the moulding around a door frame can be plain and square or richly stepped, and most people match the architrave profile to the skirting so the room feels coherent. Where the two meet at the bottom of a door frame, a carpenter cuts a neat junction so the skirting butts cleanly against the architrave.
The skill in fitting these pieces is in the joints. Internal corners — where two walls meet to form a recess — are usually scribed. Scribing means cutting the end of one board to the exact reverse shape of the moulding it meets, so the profiles interlock without an ugly gap. External corners, such as a chimney breast, are mitred: each board is cut at an angle so the two meet in a clean diagonal. Good mitres and scribes are the difference between a tidy finish and one that looks rushed.
Decorative mouldings sit above the skirting. A dado rail runs at roughly waist height and once protected walls from chair backs; a picture rail sits higher and was traditionally used to hang framed pictures from hooks. Both are largely decorative now and are a matter of taste. Cornicing — the moulding where wall meets ceiling — is sometimes timber and sometimes plaster, so it can fall to either trade depending on the material chosen.
Materials vary. Softwood is common and economical, usually painted. MDF (medium-density fibreboard) is widely used for skirting and architrave because it is stable, takes paint smoothly and comes pre-primed. Hardwoods such as oak are chosen where the timber is to be stained or left natural rather than painted. The choice affects both cost and the final look, so it is worth deciding early whether mouldings will be painted or shown off as bare timber.
Why second-fix happens after plastering
Sequencing is the whole reason for the first-fix and second-fix split. Plastering is wet, dusty work, and fresh plaster needs time to dry. Fitting fine, finished timber before that would be a mistake — the moisture and dust would mark it, and plasterers need clear walls to work against rather than skirting and architrave in the way.
There is also a practical fit issue. Plaster builds up the wall surface to its final thickness. Skirting and architrave sit against that finished surface, so they can only be measured and cut accurately once the plaster is on and level. Hang a door before the lining is plastered around and the gaps will not line up. Second-fix carpenters work to the real, finished dimensions of the room rather than to the bare structure.
The order of trades on a typical project runs roughly: first-fix carpentry, then first-fix electrics and plumbing, then plastering, then a drying period, then second-fix carpentry alongside second-fix electrical and plumbing work such as fitting sockets, switches and taps. Decoration usually follows, although many carpenters fit timber with the expectation that it will be caulked and painted afterwards. Caulk is a flexible filler used to seal the fine gap between timber and wall before painting, hiding any small inconsistencies the wall itself introduces.
Because second-fix is the last carpentry stage before decoration, it tends to be where the quality of a whole project becomes visible. Structural work can be sound but hidden; a poorly cut mitre or a door that catches on its frame is on display every day. Anyone planning work should expect a careful carpenter to take their time at this stage, check that floors are protected, and confirm the chosen profiles and finishes before cutting into the timber. It is detailed work, and the detail is the point.