These really come into their own on large areas of wall and ceiling. Provided you use the correct type for the job you will get as good a finish as with brushes or pads. Although better suited to emulsion and other water-based paints, rollers can be used to apply oil-based types, but the finish will be slightly stippled. Three basic types are available.
Foam
The cheapest type and a good general purpose roller. It gives a reasonable finish and is best suited to the application of water-based paints. Don’t overload it, as paint tends to drip easily from foam; if you press too hard paint will ooze out of the ends. If squashed while stored away, a roller will lose its shape. New sleeves can be fitted when necessary. You can also use this type of roller for applying wallpaper paste * especially with wall coverings, where the paste is applied direct to the wall.
Mohair
Here a short, fine pile sleeve is fixed to a rigid cylindrical frame which you can remove for cleaning. Suitable for use with all types of paint, it is ideal for the application of oil-based ones if you want a really smooth gloss finish.
Lamb’s wool or nylon
Available in a variety of pile lengths and thicknesses which will deal with many different types of surface, this is probably the most popular type of roller for applying water-based paints to walls and ceilings. For the best results always match a roller to the surface you are painting. Follow the general rule of a smooth surface needing a short pile and a rough surface a longer one and you will not go far wrong. Pile lengths vary from 6mm to 31mm. Bearing in mind what type is best used where, choose either a foam, short pile mohair, lamb’s wool or nylon roller for smooth or lightly textured surfaces. For highly textured surfaces pick a long shaggy pile lamb’s w6ol or nylon type. For outside walls buy a roller with a tougher pile specially designed for exterior use, as this will be more durable on rough surfaces such as stucco or pebbledash.
Don’t use a short pile roller on a heavily textured surface as the pile will not reach right into the indentations and the paint will not cover properly. Conversely a long, shaggy pile used on a smooth surface will coat too heavily. Small rollers in a variety of pile types are available for reaching behind radiators and small pipes.
Other equipment
To load your roller ready for use you will need a special paint tray (sometimes supplied with it) which is sloped at one end. Pour the paint into the deep end and load the roller by rolling hall the pile through the paint and moving up the slope to spread the paint evenly over the pile and remove any surplus. To save cleaning the tray after use, line it with aluminium foil, which you can throw away when you have finished. A step ladder with a top platform, on which to place the tray when painting ceilings, is essential unless your tray has special hooks that latch onto one of the top steps. If you do not have a step ladder you can paint ceilings from ground level with a hollow-handled roller into which you insert a long pole. For corners and edges you will need a 25mm paint brush. Paint these areas first, working round the perimeter of the ceiling.
Using a roller
To avoid splashes make sure the roller is not overloaded. Remove any excess while it is still in the tray. Take it carefully to the work surface to avoid ‘spinning’ and when it needs reloading never pull or push it sharply from the surface.
Use the roller in random directions in a crisscross pattern (to ensure even distribution of the paint) and join up all these ‘wet’ patterns before the paint has started to dry. This will be no problem as rolling paint is far quicker than working with a brush. Though oil-based paints can be cleaned off, it is a long, messy job and we recommend you keep your roller for use with water-based paints only. Most painters & decorators think it is better to keep two rollers, one for each.
Store the roller, when cleaned and dry, in a polythene bag . Avoid using a roller with water-based paints over long periods in excessively hot weather because the paint tends to dry hard on the pile. If you are painting in these conditions, wash out the roller once or twice when you reach a natural breaking-off point, such as the end of a wall.