Why Is My Paint Patchy? How to Fix Uneven Walls and Ceilings

Water-based paint dries from the outside in and from thin areas first, so for a while a wall can look mottled, darker in some places and lighter in others. That is normal. Ours is touch dry in about 30 minutes, but the colour keeps settling for a couple of hours, and longer in a cold or humid room. Leave it, keep the room ventilated and look again once it is completely dry, in daylight.

If the patches are still there when the paint is fully dry, look closely at their shape. Patches that match your repairs, filler or plasterboard joins point to uneven absorption. Patches in bands or stripes point to how the paint went on. Patches where the old colour shows through point to opacity: there simply is not enough paint there yet.

Filler, bare plaster and new plasterboard are far more absorbent than the painted wall around them. They draw the binder out of the first coat, so those areas dry duller, or sometimes shinier, than the rest of the wall. Decorators call this flashing. It is a sheen problem rather than a colour problem, and it shows most when light rakes across the wall.

The fix is to even out the absorbency before the finishing coats. Sand filler flush, dust it off, and seal each repair with a thinned coat of the wall paint before you paint the whole wall; on new or bare plaster, mist coat the entire surface. Then apply full coats over the whole wall, corner to corner. A lower sheen also helps: Dead Matt reflects so little light that small sheen differences are much harder to see than on a Matt or Eggshell.

When you go from a dark colour to a light one, or from a strong colour to a soft one, the first coat will always look patchy, because it cannot hide everything underneath on its own. The cure is enough paint, evenly spread: a properly loaded roller, a full coat and the right recoat time before the next. Spreading the paint too thin to make it go further is the most common reason a wall still looks patchy after two coats.

Our paints are made with high opacity, so two coats usually give a solid, even colour. Depending on the surface, the colour change and how the paint is applied, three coats may still be necessary. Leave 1–2 hours between coats and judge only the dried result.

Patches also come from uneven film thickness: a roller running low on paint and being pushed harder, a heavily loaded roller in some places and a nearly dry one in others, or rolling back into paint that has already started to tack off. Load the roller evenly from a tray, apply in a W, fill it in, then lay off lightly in one direction. Finish each wall in one session so you are always rolling into wet paint.

Avoid touching up single patches once the wall is dry. A dab of paint on a dried wall almost always shows, because it has a different thickness and texture. If a wall still looks patchy, apply another full coat to the whole wall, corner to corner.

High opacity means fewer coats for a big colour change, and self-levelling means the paint flows out evenly as it dries rather than leaving thick and thin areas. Our Dead Matt finish hides small sheen differences that would show on shinier paints. None of that changes how a surface absorbs paint: new plaster still needs a mist coat, and filler still needs sealing. Always test your colour with a sample first, on the wall you are painting.