Painting interior walls: coats, prep and finish

Two coats of acrylic on clean, sound walls (with a primer first if the surface is new, bare or stained). The right sheen level depends on the room: low-sheen for bedrooms and living areas, semi-gloss for kitchens and bathrooms. The thing that most affects whether the finish lasts is the prep, not the cost of the paint.4DuluxView source

If your walls are in good shape, the job is fairly simple. Cracks, water stains or peeling paint need fixing before the topcoat goes on, and that prep is a separate job with its own price. The sections below explain each part.

Two coats is the standard; a primer first if the wall needs it

For a house being repainted, the standard job is two coats of acrylic wall paint. One thick coat doesn't work as well as two thin ones. It runs, sags and dries patchy, leaving lap marks you can see in any raking light.1DuluxView source

A primer goes on first when the surface is new plaster, bare board, or has been patched. Primer seals the wall so the topcoat grips evenly; skip it on a bare or porous surface and the paint soaks in unevenly, so the patchiness shows through the finish.1DuluxView source 5Haymes PaintView source On walls that already have sound paint and aren't stained or damaged, a primer isn't usually needed.

Between coats, a light sand with 120-grit paper helps the second coat grip and knocks back any dust or nibs in the first coat.1DuluxView source Most good painters do this without being asked. It's one detail that makes the difference between a flat, even finish and one that just looks painted.

Prep decides whether the finish lasts or peels in a few years

No paint fixes a bad wall. Even a top-quality paint on a wall with old cracks, peeling sections, or a damp patch behind it will start lifting, because the problem is under the paint, not in it.4DuluxView source

Small prep (filling hairline cracks, sanding back loose edges, spot-priming patched areas) is part of what a good painter does before the first coat goes on. Bigger problems change the scope. Water damage, large peeling sections, or surface mould become a repair job on their own: quoted and priced as a separate item.

Wall condition is the biggest factor in what you'll pay for interior painting. Rooms in good shape cost less and go faster. Rooms that need real prep cost more. A painter who quotes without looking at the walls is either pricing high to cover the risk or planning to skip the prep. Walk the rooms with them before anyone puts a figure down.

The right finish for the room: low-sheen for bedrooms, semi-gloss for kitchens

Sheen is a practical choice, not just a look. Low-sheen and satin acrylics are the usual pick for bedrooms and living rooms.2DuluxView source 3TaubmansView source They hide small wall flaws (old nail holes, slight unevenness) and look clean in daylight. The trade-off: they're harder to wipe down, so a greasy mark near the light switch needs a gentle touch.

Semi-gloss is right for kitchens, bathrooms, laundries and busy corridors.2DuluxView source 3TaubmansView source It wipes clean easily, holds up to steam and moisture, and doesn't mark as fast as a flat finish. In a bathroom that gets hot showers daily, semi-gloss isn't a luxury. It's just the right product.

Kids' bedrooms and hallways are a judgement call. Some painters use low-sheen throughout for a clean finish; others choose satin in rooms that get a lot of wear. Both work well. A good painter will ask what you want before they quote.

Walls vs trim: why doors and skirting boards get a different paint

Doors, skirting boards, window frames and architraves get an enamel, not a wall acrylic. Enamel is harder and easier to clean: it takes knocks and wipes on a door edge in a way wall paint won't.7TaubmansView source Most painters in Australia now use water-based enamel for interior trim.6Dulux TradeView source It's touch-dry in 20–30 minutes, ready to recoat in about 2 hours, low in odour and stays white over time.

Oil-based enamel gives a slightly higher gloss and a very hard finish, but it needs 6–8 hours to dry between coats, has a strong solvent smell while it's on, and turns yellow in rooms that don't get much direct light.6Dulux TradeView source For most rooms in a modern home, water-based enamel is the better pick, and most painters have moved that way.

If your quote covers walls and trim together, ask which enamel they're using and on which surfaces. A good painter won't mind the question. For more on doors and trim, see the guide to painting interior doors and trim.

What does interior painting cost?

What affects what a painter charges for interior walls

Interior painting is priced by room (bedrooms, living areas, hallways), not by square metres on the invoice. Room count is the starting point. From there, four things move the price.

Wall condition matters most. A room in good shape costs less and goes faster. A room that needs real patching, crack-filling or stain-blocking costs more, and if the work is big, it gets treated as a separate job with its own price.

Ceiling height changes the setup. Standard 2.4 m ceilings are quick to work with; anything above 2.7 m usually needs a taller ladder or a platform, which adds time and sometimes a height charge.

Whether trim is included adds work. Skirting boards, architraves and window frames take real time on top of the walls alone. A quote that covers walls and trim will be higher than walls only, as it should be.

Sheen level has a small effect on how careful the painter needs to be to avoid lap marks, but it's a minor factor next to room count and wall condition.

Ceilings are a different surface from walls: different prep, different product, and a question of which goes first. If you're doing the whole room, see the guide to painting ceilings.

For actual numbers, the cost guide has what interior painting runs in your area. The estimate widget above gives you a fast live range based on current pricing.