A staple in many period properties, we explain what lath and plaster is, how these walls are constructed and how to repair them.



While lath and plaster isn’t used in modern construction, if you are the owner of an older property, there’s a possibility that your home was built using this method.

Lath and plaster was a method of finishing off walls and ceilings used from early in the 18th century right up until the mid-20th century — when modern methods for plastering walls began to be used and sheet plasterboard became more commonplace.

If your property has lath and plaster, or are considering buying one, this guide looks at how they were constructed and how they can be repaired if they are, as many will be, showing signs of wear and tear.


What is Lath and Plaster?

Lath and plaster can be identified by the presence of laths, thin strips of timber measuring around 25mm x 6mm, behind the plaster. These would be nailed to vertical timber joists or posts to form a framework for the wall. Each lath was spaced with gap of around 6mm to take the plaster which would be applied next.

Three coats of plaster were given. The first was a 6mm thick render layer designed to stick to the lath and fill the gaps between each one. Next was a ‘floating’ layer, again of around 6mm thing. This provided a smoother surface to which the final ‘setting’ layer could be applied. The setting layer was usually 3mm thick and gave a nice smooth finish to decorate.