Scrape or brush to remove all friable and loose and flaking paint

If there is mould growing on the wall treat it with a proprietory biocide.

It is best to determine what is causing the mould to grow and to remove the cause.

Spray with water before applying the Limewash so that the surface is damp.

Coverage

Ordinary Limewash covers about 3 – 4 m² per litre; 150-200 ft² per gallon.

Limewash will keep indefinitely if frost free and covered with water.

Sources

Limewash is available from most builders merchants, paint merchants and specialist suppliers, either as Limewash or lime putty.

If there is a problem with finding a supplier ask the local Conservation Officer.

Making Limewash

Limewash can be made from quicklime and hydrated lime. Each has its advantages and disadvantages and are not described here.

Limewash can be bought ready made or can be made from lime-putty which is sold in large tubs.

Lime putty is made into Limewash by adding two parts of water.

The first coat at least and preferably the second, coat as well, should be thinned with an equal amount of water.

The paint is more durable if it is put on in several thin coats

There will be sand sized lumps in the Limewash which do no great harm except in coloured Limewash where they might weather to white dots

Strain the Limewash through the leg of a pair of tights to remove these lumps.

Stir the Limewash frequently.

Waterproofers

Limewash is durable without waterproofers. There are several different waterproofers such as casein, tallow and linseed oil.

The easiest and most readily available is skimmed milk. When skimmed milk is added the Limewash must be used within two or three days.

Add a maximum of one pint to a gallon of Limewash.

The addition of skimmed milk increases the vapour permeability of the Limewash.

Equipment

Limewash is caustic so wear goggles and gloves and have clean water available to wash off any Limewash which gets into eyes or sensitive skin.

Garden pressure sprayer for water Soft brush for removing dust

Natural bristle churn brush Small and broad paint brushes

Paint kettles

Procedure

Spray a small area of wall to be painted

Brush the Limewash in all directions to force the thin Limewash into the surface.

It will be virtually transparent until it dries.

Leave for twenty four hours before recoating.

Apply several thin coats.