“Preparation is all” is a much-quoted and somewhat irritating phrase, but it is nonetheless true. The truth is that however hard you work on a finish it will only be as good as the surface you put it on, and there are few things more disheartening in decorating than having lavished time and effort on a spectacular paint effect, only to have it end up looking disappointingly rough or finding it starts to bubble or flake. Before starting work on walls, examine them for any signs of damp, crumbling or flaking plaster or cracks. If you discover any of these, for example damp, then find the cause and cure it, rather than trying to disguise the symptoms you can see.
If the walls have been painted and are in good condition then they need no more than a brush-off then a wash-down with warm water mixed with some washing-up liquid or sugar soap. Once the wall has dried thoroughly, you can hunt out any cracks that need filling. Get as smooth and level a finish as possible, then once dry sand down. When choosing a filler check that you pick the right one for the job. They range in fineness of finish, from rough exterior grade to very smooth finishes suitable for interior work. Raw plaster needs to be primed before decorating. Remember that plaster takes a long time to dry out, and even if the surface seems dry, the plaster may well be damp underneath. Fine cracks are also liable to appear as it dries, so decorating too soon can be a mistake. Always use a water-based paint so the wall can breathe.Do you want to learn more? Visit Surface preparation: taping, skim coat, plaster repairs and restoration .
If the wall has been painted with distemper or textured paint this will have to be removed before decorating. Wallpaper can most easily be removed with a steam stripper. Many washable types of wallpaper have vinyl surfaces which you can peel off, leaving a backing resembling lining paper on the wall. This makes a very good surface for painting or wallpapering on to. Alternatively, it can be stripped off.
When working with wood, again look out for any signs of problems, such as damp, which may cause the wood to warp, crack or crumble. Painted wood can be sanded and washed down with sugar soap, or, if you wish to remove the paint completely, stripped with a chemical stripper or hot-air gun. New wood must first be primed before starting work. Fill any holes with a cellulose filler and paint knots with a shellac knotting product, otherwise they may show through the paint.