Ceilings get stained by things like water leaks, candles, light bulbs, and smoke from real wood fires.
Scrubbing the stain and repainting sometimes works, but you often need to use an oil-based stain-block or damp-seal paint first (try Ronseal Damp Seal, from £7 for 400ml, B&Q), to prevent the stain coming through again (see how-to tip below).
Decorating ceilings should be done before decorating the rest of a room because of splatters and drips, so if it’s just the ceiling that needs attention, you’ll have to paint with great care.
When using oil-based paint on a ceiling, it’s essential to wear safety goggles in case the paint gets in your eyes. In fact, wearing goggles and a shower cap is always a good idea when painting a ceiling, so your face and hair don’t get covered. Attaching your paint roller to an extension pole, so you paint standing on the floor, rather than at the top of a ladder will help too. This is easier, but does make it harder to get a good finish, as you can’t see roller lines, bits you’ve missed and debris in the paint so well from the floor compared to up a ladder.
The easiest paints to use on ceilings, especially if you’re not decorating the rest of the room, are semi-solid ones, such as Dulux’s Pure Brilliant White Solid (£16.97 for 2.5ltr, B&Q). These splatter and drip less because they’re not runny, but come in a very limited range of colours. If the ceiling’s less than perfect, use a matt emulsion - one with a sheen will highlight imperfections.
Ceilings are prone to hairline cracks, especially if there are rooms above, and these are hard to eradicate permanently. Your best bet is to open up the crack slightly using the blade of a utility knife, paint PVA into it to help filler adhere and, after a few minutes, apply the filler. Try Toupret Fibacryl (£6.50 for 310ml, www.protoolsdirect.co.uk) - unlike most fillers, this seems to keep cracks closed long term. Another good solution is to paper the ceiling with lining paper, or have the ceiling replastered. The plasterer should tape over the cracks to prevent them from coming through the new plaster, but if they miss any, the cracks will reappear. Lath and plaster ceilings are particularly prone to hairline cracks and to truly get rid of them, you’ll have to pull down the ceiling (a very messy job), and start again with plasterboard.
In the past, it was common to put textured wallpaper, Artex or polystyrene tiles (which can be a fire hazard) on ceilings. Replastering the ceiling is usually the easiest and best solution, but you will have to remove the wallpaper and tiles first, which can be hard work.