Why Prep Matters Most

When someone sees a freshly painted room, they see the color. What they don't see are the hours of work that happened before the first tin was opened — and it's exactly those hours that decide whether the result looks professional or amateur.

Most of the flaws we see on walls — scratches, holes from picture frames or shelving, crackingCrackA split or gap in render, concrete, a wall, a coating or wood. Fine cracks are usually only on the surface; ones that grow, keep reopening or run diagonally need attention. at the corners where two walls meet — aren't actually a paint problem at all. They're a filling problem. Expensive paint applied over a surface like that doesn't hide the flaw — if anything, it often highlights it, especially if the paint has any sheen that catches light at an angle.

SandingSandingSmoothing a surface with sandpaper or a power sander to remove bumps, loose old paint or gloss, so the new paint or varnish grips well and comes out smooth. the old surface before filling serves a double purpose: it removes any loose flakesPeeling paintWhen paint loses its grip and lifts off in flakes or sheets. It is almost always a sign of a problem underneath, usually damp or poor preparation. of old paint that would prevent proper adhesion, and it creates a slightly rough surface that the new material can grip onto. Skip this step, and even the best fillerFillerA fine paste or powder that fills holes, fine cracks and dents so a wall, ceiling or piece of wood is smooth before it is painted. can flake off in chunks within a few months.

PrimingPrimerThe thin first coat that goes on before the main material. It binds dust, seals the pores and helps paint or waterproofing stick firmly., finally, is the step most DIYers skip because "it doesn't show." On new plasterRender (plaster)A layer of mortar (sand, cement or lime, and water) spread over brick or concrete to give a wall a straight, sound surface ready for paint or tiles., or on a wall going from a dark to a light color, primer evens out the surface's absorbency so the finish coat spreads evenly and only needs two coats instead of three or four.