plasteronlath

Plaster on lath is a traditional building method used for interior walls and ceilings. It involves applying layers of plaster onto a substrate of lath, which is typically thin strips of wood or metal. The lath acts as a keying mechanism, providing a surface for the plaster to adhere to and creating a continuous, monolithic finish.

The lath is usually installed in a closely spaced pattern, with small gaps between the strips. This allows the plaster, particularly the initial "scratch coat," to be pushed through the gaps and key onto the back of the lath. This mechanical bond is crucial for the structural integrity of the plaster system, preventing sagging and cracking. Subsequent layers of plaster, known as the "brown coat" and the "finish coat," are then applied to build up the desired thickness and achieve a smooth surface.

Historically, wood lath, often made from oak, pine, or cedar, was the most common material. As construction techniques evolved, metal lath, made from expanded metal or wire mesh, gained popularity for its durability and fire resistance. Plaster on lath is known for its soundproofing qualities and its ability to create curved or irregular surfaces. While less common in modern construction due to the labor-intensive nature of the process and the availability of alternative materials like drywall, plaster on lath remains a hallmark of historic buildings and is still employed in restoration projects and for high-end finishes.