On most extensions and renovations, the plasterers get the credit for the moment a building starts to look like a home. What they are actually working on is the carpenter's work from the week before. Every wall they skim, every ceiling they board and every reveal they finish sits on timber that somebody has set out, levelled and fixed. Get that stage right and plastering is quick and clean. Get it wrong and the problems show up in wavy walls, cracked corners and doors that never quite close.

Here is what happens on site during first fix carpentry, and why it matters more than most homeowners expect.

Setting out and structural timber

The first job is rarely cutting anything. It is setting out: marking wall lines on the floor, checking them against the drawings, and working out how square and how level the existing building actually is. Hampshire has a lot of Victorian and older housing stock, and in those houses almost nothing is square. A carpenter who sets out from a wall that leans by 20mm will pass that lean into every room he builds.

Once lines are agreed, structural timber goes in. That means floor joists, trimmers around openings, and any roof structure. On loft and extension work this is also when a cut roof is built in place, rafter by rafter, rather than delivered as trusses. Anything carrying load is fixed with the correct hangers, straps and fixings, because building control will want to see them before they are hidden.

Stud walls, noggins and fixing points

New internal walls are framed next. A good stud wall is not just uprights at 400mm centres. It also contains noggins, which are the short horizontal pieces fixed between studs to give solid backing wherever something will later be screwed to the wall.

Noggins are the detail that separates a considered job from a fast one. Before the plasterboard goes on, a carpenter should be thinking about:

Wall-hung radiators, basins and cisterns, which need timber behind the board
TV brackets and shelving, positioned at the height the client actually wants
Kitchen wall units, so the run of cabinets has continuous fixing
Handrails, grab rails and curtain poles
Board edges, so every sheet of plasterboard lands on solid timber

It costs a few minutes each to add. Retro-fitting them after plastering means cutting the wall open again, so this is worth walking round and discussing on site before the boards go up.

Working around the other trades

First fix is a shared stage. Electricians are running cables, plumbers are running pipes, and both need holes through joists and studs. There are rules about where those holes can go: drilling through the middle third of a joist's depth is acceptable, notching the top edge deeply is not. A carpenter who is on site while the services go in will spot a joist that has been cut in the wrong place and fix it before it is buried.

The same applies to service voids and boxing. Soil pipes, extract ducts and boiler flues all need framing around, and that framing should be planned so it looks deliberate rather than like an apology in the corner of the room.

Floors, ceilings and linings

Before plastering, floors are usually decked out in structural sheet material so everyone has a safe, level surface to work from. Ceiling joists and battens are levelled, because a ceiling that is 10mm out over three metres will be obvious once the light rakes across the plaster.

Door linings are the last big first fix item. They are fitted plumb, square and to the correct width for the finished floor build-up, then held with temporary bracing. When the plasterers arrive, the lining edge gives them a clean stop to work to. If linings are twisted at this stage, the door will bind later and no amount of adjustment at second fix will fully correct it.

Why the sequence saves money

The reason this stage is worth doing carefully is simple: after plastering, everything is hidden and every change becomes disruptive. Adding a socket, moving a doorway by 100mm or fitting a heavy mirror all turn into dust, patching and redecoration. A half day spent checking levels, noggins and lining positions before the plasterers start is the cheapest half day of the whole project.

It also keeps the programme honest. Plasterers work fast, and they cannot start until first fix is genuinely complete. A site that is 90 per cent ready usually loses a full day of everyone's time.

Talk it through before the boards go on

PRM Carpentry handles first fix work across Hampshire, from single-room alterations to full extensions and loft conversions. Costs vary widely with the size of the structure and how straight the existing building is, so any figure quoted without a site visit is guesswork. Every job differs, and we would rather look at it properly.

If you have a project coming up and want the timber stage done so the rest of the build runs smoothly, take a look at our first fix carpentry service or get in touch for a free, no-obligation quote.

What a Carpenter Does Before the Plasterers Arrive