At a glance
Painting is one of the most transformative DIY jobs you can tackle at home. A freshly painted room – done properly, with the right preparation and the right product – looks completely different from one that was simply given a quick coat over old, flaking paint. The difference between a professional finish and a patchy disappointment is rarely down to the paint itself. It is almost always in what happens before the brush touches the wall: the filling, the sanding, the priming, and the correct choice of product for the surface being painted.
This guide covers every common interior surface – walls, ceilings, bare and previously painted wood, metal, and radiators – with the right approach for each. Whether you are refreshing a single room or working through an entire house, the same principles apply: prepare thoroughly, use the right primer, apply thin coats and allow proper drying time. Rush any of these steps and the finish will show it.
What you’ll need
Choosing the right paint
The single most common mistake in home painting is applying the wrong product to the surface – using matt emulsion on woodwork, applying eggshell over bare plaster without primer, or reaching for the cheapest available option without understanding what the sheen level actually means for durability in that space. Understanding the relationship between surface type, sheen level and the paint’s base (water or oil) makes every subsequent decision much easier.
Water-based paints now dominate the market and for good reason. They dry faster, produce less fume, clean up with water and have improved dramatically in terms of durability and finish quality. Oil-based paints are still used by some tradespeople for high-traffic woodwork because of their exceptionally hard finish, but the drying time (often 16-24 hours between coats) and the need for white spirit for clean-up makes them increasingly impractical for most DIY projects. The technology gap has closed considerably in recent years.
Surface preparation
There is no shortcut to good preparation. A well-prepared surface will hold paint for years; a poorly prepared one will show brush marks, peel within months and require repainting far sooner than necessary. The time investment in preparation is repaid many times over in the quality and longevity of the finished result. This is the step that most DIY painters underestimate and the one that most clearly separates professional-quality work from amateur results.
The required level of preparation varies by surface and condition. New plaster needs to dry completely before painting – typically 4-6 weeks for fresh plaster – and should then receive a mist coat (heavily diluted emulsion) to seal the surface before a full topcoat. Previously painted surfaces in good condition need little more than cleaning, light sanding to provide a key, and filling any cracks or holes. Bare wood always needs primer before any topcoat, as raw timber will absorb paint unevenly and the finish will be poor however many coats are applied on top.
Wipe surfaces with a damp cloth before sanding, not after. Sanding creates fine dust that settles across the room. Do your filling, let it dry fully, then sand – but do the final wipe-down with a slightly damp cloth just before you prime or paint. A dry room and a clean, dust-free surface is the foundation of a great finish.
Painting walls and ceilings
Walls are the most straightforward painting job in the house but still reward a methodical approach. The technique that consistently produces the best finish is cutting in first with a brush around all the edges – at the ceiling line, around sockets and switches, above skirting boards, in corners – then filling the main area with a roller before the cut-in dries. This wet-on-wet approach blends the brush and roller marks together and avoids the hard edge line that appears if the cut-in dries before rolling begins.
Ceilings should always be painted before walls. This way, any paint that drips or roller-splashes onto the walls can be covered when the walls are done. Work in sections from the window outward, keeping a wet edge as you go. Most ceilings need two coats of good quality ceiling paint, and a third may be necessary when covering dark colours or applying fresh emulsion over nicotine-stained surfaces.
Painting wood and skirting boards
Woodwork requires more preparation than walls but rewards the effort with a finish that can last a decade or more if done properly. The key difference from wall painting is the need for primer on bare wood, thorough sanding between coats, and the use of a higher-sheen paint that can withstand knocks and cleaning. Skirting boards, door frames, architraves and window boards all follow the same process.
Previously painted wood in good condition needs less work. Light sanding with 120-grit paper to provide a key, wiping with a damp cloth, and then two coats of a water-based eggshell or satin will produce an excellent finish. Where old paint is chipping, flaking or soft – which often happens on wood that was painted with oil-based gloss many years ago – it is worth considering stripping back to bare wood using a heat gun or chemical stripper before starting fresh. Painting over deteriorating old paint simply delays the inevitable.
Painting metal and radiators
Metal surfaces in the home – radiators, pipes, cast iron fireplaces, metal window frames – require a slightly different approach. The challenge with metal is adhesion: paint applied directly to bare or rusty metal without the correct primer will simply flake off over time, particularly on surfaces that heat up and cool down repeatedly like radiators. The expansion and contraction cycle stresses any paint film that has not bonded properly to the substrate.
For radiators, the essential product is a dedicated radiator paint or radiator enamel, formulated specifically to withstand the heat range that domestic radiators produce (typically 50-80 degrees Celsius at their surface). Standard eggshell or gloss will discolour and crack on a working radiator within a season. Always paint radiators when they are cold and have been off for at least 24 hours, and do not turn them back on until the paint is fully cured – which for most radiator paints means 24 hours at room temperature, not just dry to the touch.
Common questions and fixes
Even with careful preparation and good technique, painting throws up questions – particularly when dealing with specific problems like stains showing through, paint not covering properly, or brush marks visible in a finished surface. The answers are almost always rooted in understanding why the problem occurred rather than simply applying another coat on top.
Never paint over mould without treating it first. Painting over mould – even with specialist anti-mould paint – will not kill the underlying growth and it will reappear within weeks. Treat mould with a bleach-based solution or commercial mould killer, allow to dry completely, address the underlying damp or ventilation issue, and then prime and paint. Skipping the treatment step wastes time and money.
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