Room and wall painting

Painting one room or one wall

A lot of decorating is small in scope: a bedroom before a new arrival, a living room that has faded, or one feature wall behind a bed or sofa. A room can be quoted on its own, and walls can be done without the ceiling or woodwork if those are still in good order (see ceiling painting and woodwork painting for when they are not).

A feature wall is quick but not trivial. The corners where the new colour meets the neighbouring walls and ceiling need clean, straight cut-in lines, and deep colours often need a third coat to look even under a ceiling light.

How are walls prepared?

• Cracks are raked out, filled and sanded flush. Cracks that keep returning at wall and ceiling joints can be filled with a flexible filler or taped.
• Holes from screws and picture hooks are filled and sanded.
• Grease and handprints, especially around switches and in kitchens, are washed off so the paint adheres.
• Filled patches are spot-primed so they do not show as flat or shiny areas.
• Flaking or poorly bonded old paint is scraped back and the edges feathered in.

On new plaster the first coat is a mist coat of thinned matt emulsion. Skipping it is one of the most common reasons fresh paint peels.

Painting new plaster: the mist coat

Fresh plaster is thirsty. If full-strength emulsion goes straight onto it, the plaster pulls the water out of the paint before it can bond, and the finish can flake or peel in sheets months later. A mist coat, a matt emulsion thinned with water, soaks in, seals the surface and gives the finish coats something to grip.

Plaster also has to be dry first. A freshly skimmed wall usually needs a week or more to dry out, and a full float and set takes longer, particularly in winter. Dark patches mean it is still damp. Once it is uniformly pale, it gets the mist coat, then two full coats. The paint calculator allows for the extra coat when you select new plaster, and the Instant Quote asks whether any walls are newly plastered so the preparation is priced in.

Changing colour: dark to light, light to dark

Going from a dark wall to a pale one takes more work than people expect. Two coats of a light colour rarely hide a deep red, navy or charcoal evenly, so either a tinted basecoat or a third coat is needed. Going the other way, a deep colour over a pale wall also benefits from an extra coat to reach its full depth without patchiness.

If you are still deciding, paint large sample cards and move them around the room in morning and evening light. Many Victorian terraces in Ealing have long rooms with a window at one end only, where a colour can look noticeably darker at the back. Our guide to choosing paint colours explains how aspect changes a colour.

How much does it cost to paint a room?

The cost to paint a room depends on its size, the ceiling height, how much preparation the walls need and whether the ceiling and woodwork are included. As examples, a box room, walls and ceiling, typically comes to £450–£560, and a double bedroom with walls, ceiling, woodwork, one door and a window typically comes to £760–£1,120.

For your own room, the Instant Quote asks for the room type, size and condition and gives an indicative range, which a decorator then turns into a fixed price. If you are buying paint yourself, the paint calculator estimates how many litres you need.

How long does it take to paint a room?

A straightforward bedroom in good condition, walls only, can often be finished in a day. Add the ceiling, woodwork and some crack repair and it becomes two to three days, largely because filler, primer and each coat need time to dry before the next step. Water-based emulsions are usually ready to recoat in two to four hours in a warm, ventilated room; cold, damp rooms take longer.

Which finish should walls have?

Flat matt hides uneven plaster well and suits period rooms, but it marks more easily. A durable or scrubbable matt looks almost the same and wipes clean, which is why it is the usual choice for hallways, kitchens and children's rooms.

Soft sheen and silk finishes are more wipeable still, but they show every bump in the wall. They are best kept to bathrooms and to walls with very flat plaster.