Prepare the surface properly, then roll in slow overlapping strokes keeping a wet edge to avoid ridges and roller marks.
SF-01Clear and protect the roomMove furniture away from the walls or out of the room. Lay dust sheets over the floor and any furniture left behind. Take down curtains, blinds and anything hanging on the wall you're painting.
SF-02Fill and sand any dents or cracksRoller marks are often just paint sitting over old damage. Fill small holes and cracks with a quick-dry filler, let it go off, then sand flush with fine sandpaper. Run your hand flat over the wall afterwards — you shouldn't feel any ridges.
SF-03Dust down and wipe the wallSanding leaves fine dust that stops paint sitting flat and causes a gritty, uneven finish. Wipe the whole wall with a slightly damp cloth or a tack cloth and let it dry fully before you paint.
SF-04Mask edges, sockets and skirtingRun masking tape along the skirting, around socket faceplates, and along any edge where you want a crisp line. Press the tape down firmly so paint can't creep underneath.
SF-05Cut in the edges with a brush firstPaint a 50-75mm band with a brush along the ceiling line, into corners, and around fittings before you roll. This stops you dragging a half-loaded roller into corners later, which is a common cause of patchy marks.
SF-06Pick the right roller sleeve and load it evenlyUse a short-pile foam or velour sleeve for a smooth wall finish — a thick pile leaves a stipple texture. Load the roller in the tray, then run it over the ridged part of the tray a few times so it's evenly covered, not dripping or patchy.
SF-07Roll in a W pattern and keep a wet edgeRoll a rough W or M shape roughly 600mm wide, then fill it in without lifting the roller off the wall too soon. Always work into the wet edge of your last stroke rather than starting on dry paint — that's what causes visible lines and lap marks. Use light, even pressure; pressing hard squeezes paint out unevenly.
SF-08Apply a second coat once fully dryCheck the tin for drying and recoat times — most emulsions need 2-4 hours, but a damp room can take longer. Lightly key the surface with a dry roller pass if it's been over a day. Roll the second coat the same way as the first, keeping the wet edge.
SF-09Check under raking light and touch upOnce dry, shine a torch or lamp across the wall at a low angle — this shows up any ridges, thin patches or roller marks you'd otherwise miss under normal light. Lightly sand any hard ridges and touch up with a small amount of paint, feathering the edges.
SF-10Clean tools and tidy upWash rollers and brushes in warm water for water-based paint, or the correct solvent for oil-based paint — don't pour solvent down the drain. Peel off the masking tape while the paint is dry but not fully cured, pulling it back on itself at a low angle to avoid tearing the paint edge. Fold and store dust sheets once the room is fully dry.