Limewash Paint for Interior Walls: A Practical Guide for London Homes

What Limewash Actually Is

Limewash is one of the oldest interior wall finishes in existence. At its most basic, it is slaked lime (calcium hydroxide) dispersed in water, sometimes with a small amount of tallow or linseed oil added to improve adhesion and durability, and tinted with natural pigments. When applied to a porous substrate, it carbonates — absorbing carbon dioxide from the air and converting back to calcium carbonate — bonding physically and chemically with the surface.

The result is a finish unlike any modern emulsion: translucent, subtly textured, with a softness and depth that varies across the wall as light changes throughout the day. This is precisely what makes it appealing in period London properties, and precisely why it requires a different approach than standard decorating.

Which Substrates Suit Limewash

Limewash works best on — and in traditional buildings should only be used on — porous, breathable substrates. Ideal surfaces include:

Lime plaster. Original lime plaster on lath, found in pre-1900 London properties, is the natural partner for limewash. The plaster and the wash are compatible materials: both breathe, both are alkaline, and limewash will bond properly.

Sand and cement render (with caveats). Modern sand-and-cement render is too dense for traditional limewash. Use Keim Granital or Keim Innotop instead — these are silicate-based mineral paints that share limewash's breathability and aesthetic but bond to harder substrates.

Bare brick. Unglazed brick is porous enough to take limewash. Expect the colour to be absorbed unevenly, which enhances the rustic character if that is the intention.

Previously limewashed surfaces. If a wall has been limewashed before and the old wash is sound (brush it firmly — it should not powder excessively), new limewash will bond well.

Unsuitable substrates include: modern emulsion paint (limewash will not bond, or will peel); plasterboard; any surface that has been painted with an impermeable coating; and smooth, hard modern plaster. Do not apply traditional limewash over these — it will fail.

Preparation

On suitable lime plaster: brush down any loose material, fill any holes with a lime-based filler (Toupret Fibacryl is not correct here — use NHL 2 or 3.5 mixed with sharp sand), and allow to cure fully before painting. The wall does not need to be primed.

If there is any existing emulsion on the wall, it must be removed. This is often impractical for large areas; if removal is not feasible, consider Keim Innotop (a mineral paint formulated to bond to previously painted surfaces) as a pragmatic alternative that delivers a similar aesthetic.

Application Technique

Traditional limewash is applied in thin, watery coats with a wide, soft brush — a lime wash brush (also called a distemper brush), which is a wide, floppy natural-bristle brush designed to work the material into the surface. Roller application is not appropriate: it creates a thick, uniform film that prevents the characteristic translucency and carbonation.

Each coat must be applied to a slightly damp surface — mist the wall with clean water using a garden sprayer before each coat. This slows the drying, gives more working time, and helps the wash penetrate rather than skin over. Between coats, allow to dry fully (typically 12–24 hours depending on temperature and humidity). Apply three to five coats for full coverage; the depth of colour builds gradually.

Direction matters. Work across the wall in loose, criss-cross strokes rather than in a single direction — this creates the varied surface texture that gives limewash its character. On smooth plaster, the effect will be subtler; on textured or skim plaster, more pronounced.

Achieving the Right Effect

Limewash finishes dry significantly lighter than they appear when wet. Test on a small area and allow to dry completely before assessing. The final colour will also shift over weeks as carbonation continues.

The effect can be adjusted: more coats give deeper, more opaque coverage; fewer coats allow more of the substrate to show through. Some decorators deliberately apply the final coat inconsistently — heavier in some areas, lighter in others — to enhance the organic variation. This is a legitimate technique in rooms where a characterful, imperfect finish is the goal.

Recommended Brands

Keim Optil. A mineral-based limewash paint suitable for interior use. Formulated for professional application, with consistent pigmentation and good carbonation. Available in a wide colour range. This is our default choice for interior limewash work on lime-plastered walls.

Earthborn Claypaint. Not strictly a limewash but a clay-based emulsion that achieves a broadly similar aesthetic on a wider range of substrates, including modern plaster and plasterboard. Low-VOC, breathable, and available in an excellent colour range. A practical choice where limewash compatibility is uncertain.

Edward Bulmer Natural Paint. A small British company producing limewash and distemper from historic recipes and natural pigments. The colour palette is exceptional — drawn from Georgian and Victorian historic interiors — and the products are formulated with traditional tallow rather than synthetic binders. More expensive and less tolerant of imperfect substrates, but the results justify the care required.

When to Call a Professional

Limewash application is not difficult, but it rewards experience. Achieving an even, controlled effect without lap marks, tide lines or excessive variation requires practice and the right tools. For period properties where the investment justifies proper execution, professional application is worth it. Contact us or request a free quote to discuss limewash work in your London property.