Lime wash is one of the most traditional ways of painting walls. Made from limestone that has been crushed, burnt and slaked with water, lime wash gives a chalky white finish to walls. It is most effective when used on porous walls. Lime wash forms a protective barrier to prevent walls from being damaged by the elements. Lime forms the protection by sinking into the wall and reacting with carbon dioxide in the air, to form calcium carbonate. You can use this traditional painting method with a few household items.
Wet the wall area you are going to paint with lime wash. Make sure the wall area is fully soaked or it will draw all the water out of the lime wash paint.
Dip a rag into your lime wash solution and start working it over an area of the wall. Rub the lime wash in a circular motion. Keep going back over the same area until it has been properly worked into the wall. Repeat until the entire wall is coated with lime wash.
Leave the wall for three of four days to "cure" then apply another coat using exactly the same method. Indoor walls will need three to four coats, outdoor walls five to six coats.
If adding colouring to your lime wash paint, ensure you make up enough solution for the last coat to cover the entire wall. Otherwise the depth of colour will vary on different sections.
Lime wash works best on porous walls. It is not advisable to lime wash cement rendering or hard gypsum plaster. Adding skimmed milk to your lime wash solution helps it bond better to these less adhesive surfaces but the end result will not look as good.