Limewash Or Clay Paint For A Matt Wall

Even colour or deliberate cloud

Limewash is a mineral coating that sinks into the wall and moves with it. The movement in the finish comes from a wide block brush laid cross hatch and from the dilution, not from a glaze added afterwards, and the tone varies slightly and deliberately. If you want a flat even wall with no cloud, limewash is the wrong product.

Clay paint gives a deep matt, chalky, slightly velvety surface with a consistent colour. It is applied with a soft brush cutting in and a short pile roller for the bulk, and the final coat is worked in one direction so raking light does not show laps. It is the answer for people who like the matt depth but not the variation.

• ✓Want tonal movement and a hand applied look: limewash
• ✓Want a uniform matt colour: clay paint
• ✓Want either one judged properly: look at a cured sample, not a wet wall

Coats, coverage and how long the wall is out of use

That carbonation period matters for anyone choosing colour. Limewash lightens considerably as it cures and only settles after a couple of weeks, which is why colour is agreed on a cured sample panel on your own wall rather than a wet one. Judging it wet is how people end up two shades darker than they wanted.

Clay paint behaves more like a conventional decorating job in programme terms, which is part of its appeal on a room that has to be back in use quickly.

Limewash coats

Two to four, brushed cross hatch, more coats deepen and even the tone

Limewash drying

4 to 6 hours between coats, full carbonation over 2 to 4 weeks

Clay paint coats

Typically two coats over a clay primer

Clay paint coverage

7 to 10 m2 per litre per coat

Clay paint VOC

Effectively zero

Breathability and the walls that need it

Both are breathable, and neither is a plastic film. Limewash stays vapour open so the wall can dry inwards, which is the whole point on an old Sussex farmhouse, on lime plastered walls in listed and period properties, and on damp prone masonry. It will not cure a damp problem, but it stops moisture being sealed in behind a film. Fix the source first, then limewash over the repair.

Clay paint absorbs and releases humidity and suits plaster, lime plaster, clay plaster and previously painted walls once primed. It is effectively zero VOC, which is why it gets specified in nurseries and children's rooms.

Neither can be applied straight over old vinyl or acrylic emulsion. Limewash needs abrading and priming, clay paint needs a bonding primer sized to the existing paint chemistry, or it flakes.

Touch, cleaning and the rooms to avoid

1. 1
   Low touch rooms

   Bedrooms, snugs, living rooms and feature walls suit either. Clay paint lasts as long as good emulsion in these rooms, and limewash gives the cloud.

2. 2
   Hallways and stairwells

   Limewash has low wipeability unless a mineral fixative is added, which improves rub resistance. Clay paint has an optional compatible natural sealer for high touch areas that raises durability without losing the matt look.

3. 3
   Kitchens

   Sealed clay paint is workable outside the splash zone. Behind a hob, neither is correct, and a mineral silicate or microcement finish is the right call.

4. 4
   Bathrooms

   Clay paint is fine above splash lines and outside the shower area, where it helps regulate humidity. In wet zones, use a tanked microcement build up instead.

5. 5
   Outside

   Limewash goes on mineral render and masonry, timed away from frost and strong sun and usually with an extra coat, because weathering is part of the look. Clay paint is an interior finish.

Cost drivers and which to pick

On limewash the cost sits in preparation and in getting the absorbency of the wall consistent. Old lime plaster drinks unevenly, so the wall is damped, the suction read, and the dilution adjusted rather than fighting it with extra coats. Modern plasterboard and gypsum skim need a mineral primer or the coating dusts off. The number of coats you choose, two to four, then moves the figure.

On clay paint the paint itself costs more than emulsion, but the total room cost is often similar because it covers well and does not need multiple base coats over new plaster. Priming is the line that decides whether it lasts.

So: period, breathable or damp prone walls, exteriors, or anyone who wants visible hand applied movement, choose limewash. Even matt colour, a nursery, a fast programme, or a previously painted modern interior, choose clay paint. If the wall is in a shower or behind a hob, the honest answer is that neither of these belongs there.