Which roller nap or pile do I need?

Roller pile is a match to the texture of the surface. Too short and the paint bridges the hollows without filling them; too long and the roller holds so much paint it leaves a stippled orange-peel finish.

Step by step

1. Look at the surface texture first.Run a hand over it. A smooth skim, a lightly textured wall, a woodchip paper and a rendered exterior wall all need different piles.
2. Use short pile for smooth surfaces.Four to six millimetres, or a foam or microfibre sleeve, for flush doors, cabinets, MDF and smooth plaster with gloss, satin or eggshell paint.
3. Use medium pile for normal walls and ceilings.Ten to twelve millimetres is the general-purpose choice for emulsion on plastered walls. It carries enough paint to be efficient without heavy stipple.
4. Use long pile for texture.Eighteen millimetres and above for artex, woodchip, brick, render and masonry. The pile has to reach into the hollows, and a short roller simply paints the high points.
5. Match the sleeve material to the paint.Synthetic sleeves for water-based paint, and check the sleeve is rated for solvent-based paint before using it with oil paint, which can destroy some foams.
6. Choose the roller width for the job.A nine-inch roller for walls and ceilings, a four-inch mini roller for behind radiators and small panels, and a narrow radiator roller on a long handle for the awkward gaps.
7. Prepare a new sleeve.New rollers shed fibres. Wrap and pull off masking tape, or wash and dry the sleeve, before using it on a finished surface.
8. Do not overload it.Dip in the tray and roll out on the ramp until it is evenly loaded and not dripping. An overloaded roller spatters and runs regardless of pile length.
9. Keep a wet edge.Work in manageable sections and overlap into the wet paint. Rolling into paint that has begun to set produces visible lap marks in any sheen above matt.
10. Lay off in one direction.After spreading the paint, finish each section with light parallel passes in the same direction. It evens the texture and hides the joins.

Tips

• Medium pile for walls, short pile for woodwork, long pile for texture. That covers almost everything.
• Wrap masking tape round a new roller and pull it off to remove loose fibres before starting.
• A mini roller with a foam or microfibre sleeve gives a near-sprayed finish on doors and cabinet fronts.

Common mistakes

• Using a long-pile roller on smooth plaster — It carries far more paint than a smooth surface needs and deposits it in a heavy stipple. The result is an orange-peel texture that is very obvious in raking light.
• Using a short-pile roller on textured wallpaper or artex — The pile cannot reach the hollows, so it paints the high points and leaves the recesses showing the old colour. It looks patchy and needs many more coats.

If it doesn't work

Questions people ask