What is lath and plaster? The lath and plaster technique was generally used to finish interior walls and ceilings from the 1700s to the early-to-mid 1900s before it was superseded by modern gypsum plaster and plasterboard.

When did they start using lath and plaster?

The process of lath and plaster was developed during the 17th century; however, it did not reach widespread use until the 18th century.

How can you tell how old a plaster is?

You can determine the approximate age of your home by the type of plaster and/or the way it’s applied. If you have wood lath behind the plaster, your walls are probably built before 1930 or so. If there is horse hair in the brown coat (the layer under the white coat), the wall probably was built before 1900.