Interior painting preparation is more than filling and sanding. Much of what decides how a painted room turns out happens earlier: settling exactly what is being painted, fixing problems that paint would only cover up, checking for old lead paint or textured coatings before anyone sands, and clearing the room so the work can be done properly. This checklist follows that order. The hands-on surface work of washing, scraping, filling and priming walls is covered separately on our wall preparation and filling page; everything else is here.
Before buying paint: pin down the job
- List every surface. Walls only, or ceiling, skirting, doors and frames, window boards, radiators and exposed pipes too? Each one adds time and may need a different paint.
- Test colours properly. Look at samples in morning and evening light, on more than one wall. Painting samples on card or lining paper lets you move them around and avoids thick sample patches on the wall, which can leave a slight ridge or sheen difference under the final coats.
- Choose the finish for each surface. Matt, durable matt, kitchen and bathroom paint and trim finishes behave very differently; our interior painting page has a room-by-room guide to sheen levels.
- Work out quantities. Use the coverage figure on the tin, allow for two coats as a minimum, and more where a dark colour is going pale or the surface is new plaster. Buying enough tinted paint at once avoids slight colour differences between batches.
- Renting? Get the landlord’s or agent’s agreement to colours before starting.
Problems to solve before painting, not during
Paint covers marks. It does not fix causes, and a few problems will simply come back through a new finish if they are painted over:
- Damp patches. A stain that is still damp, or one that has returned after being painted before, needs its cause found first. Our guide on what to do about a water leak at home covers the common sources.
- Mould. It needs cleaning and treating, and a plan for ventilation, or it tends to reappear in the same corner.
- New plaster. It must be completely dry before decorating, which can take weeks after plastering.
- Cracks that keep coming back, especially diagonal cracks from the corners of doors and windows. These can indicate movement and are worth having looked at before decorating. Our guide to preparing damaged walls before decorating explains how to check whether a crack is still moving.
- Holes and damaged plasterboard beyond what filler can deal with. Those need a proper drywall or wall repair first.
- Wallpaper. Decide whether it stays or goes before anything else; our guide on whether to remove wallpaper or paint over it walks through the checks.
- Tired or cracked sockets and switches. If they are due for replacement, doing it before painting saves masking round them and disturbing fresh paint later. Our guide on when to replace electrical sockets explains the signs.
Check these before anyone sands or scrapes
Sanding and scraping turn old coatings into dust. In older properties it is worth knowing what is on the walls and woodwork before that happens.
| What you may have | Why it matters | What to do |
|---|---|---|
| Old paint on woodwork, doors or walls in an older home | Lead paint was common before the 1970s, and paint made before 1992 could still contain lead. Exposure is mainly a risk when the paint is sanded or removed | Do not dry-sand, burn off or scrape it until you know. GOV.UK notes that home test kits can give a false answer, so get advice, and keep children away from the work |
| Textured coatings on ceilings or walls | Some textured coatings applied before 2000 may contain asbestos | Paint over sound coatings rather than sanding or scraping them; have them tested before any removal |
| Gloss on skirting, frames and doors | Water-based paint applied straight over old oil-based gloss can peel | Rub a hidden spot with a cloth dampened with methylated spirits: water-based paint usually softens, oil-based does not. Key the surface and use a suitable primer if it is oil-based |
| Chalky, shiny or flaking walls | New paint will not bond well to them | See the simple wipe and tape tests on our wall preparation page |
The lead information comes from GOV.UK’s lead information for the public, and the asbestos point from the HSE’s asbestos guidance.
The days before: clearing and protecting the room
- Empty what you can. Whatever stays goes to the middle of the room, away from the walls, and is covered.
- Take things off the walls. Pictures, mirrors, shelves, curtain poles and blinds. Bag and label the fixings, and decide now whether the old holes will be filled or reused.
- Remove door handles from doors being painted, rather than painting round them.
- Decide about radiators. Painting properly behind a radiator means taking it off the wall, which involves isolating and draining it and is a plumbing job. Otherwise, paint what can be reached.
- Mask sockets and switches. Covering faceplates with tape is enough for most jobs. Loosening them exposes live terminals, so leave that to someone competent working with the circuit switched off.
- Protect the floor. Cotton dust sheets absorb drips and do not slip. Plastic sheeting is waterproof but slippery and leaves spills wet, so on carpet it works best under a cotton sheet rather than on its own.
- Smoke alarms. If one is covered to keep sanding dust out, uncover it at the end of each day.
- Plan for pets and children. Keep them out of the room while paint is wet and while any sanding is going on.
On the day: conditions that affect the finish
Paint needs the right conditions to dry and harden properly. Check the minimum application temperature and the recoat time on the tin. A cold or damp room slows drying, and paint applied in those conditions may not cure as it should. Keep the room ventilated during and after painting, and keep the heating on low in colder months rather than switching it off.
Good light matters more than people expect. Thin patches and missed edges are easy to miss under a single ceiling light, so check coverage in daylight or with a torch held close to the wall. Any washing-down needs to be completely dry before the first coat goes on.
If someone else is doing the painting
Most disputes over decorating come from assumptions that were never discussed. Agree these before the first visit:
- Which surfaces are included, and how many coats.
- Who supplies the paint, with colours and finishes chosen before the start date.
- What you will clear and what the decorator will move, and anything heavy or fragile that cannot be moved.
- Known problems such as damp, cracks or flaking paint, so they are included in the price rather than discovered halfway through.
- Access arrangements, especially if the property will be empty.
If you would like the whole room handled, Voltify Contractors’ interior painting service covers walls, ceilings and woodwork, including the preparation. If you plan to apply the finish coats yourself, a preparation-only visit through our wall preparation service deals with the filling, sanding and priming first.
