Until around the 1930s, walls and ceilings in most homes were plastered using traditional lime or lime and earth-based plasters. Unlike modern cementitious or gypsum plasters, these allow walls and ceilings to breathe and flex and are often mixed with animal hair or hay to reduce shrinkage and offer strength. Historically, this plaster was applied in one to three coats.
Any repairs to these surfaces should therefore be carried out using a compatible mix. Plastering is specialist work: limes are alkaline and caustic and are potentially harmful to eyes, skin and lungs, so wear safety glasses and gloves and, if
