What is the purpose of lath in a building?

Lath serves a crucial function in building construction by acting as a base for plaster, shingles, or tiles. This material, often made of wood or metal, creates a framework that supports these finishing materials, ensuring they adhere properly and maintain structural integrity. When plaster is applied, for example, it bonds to the lath, allowing for a solid and durable surface finish. In roofing applications, lath can provide a necessary backing for shingles or tiles, helping to secure them in place and contribute to the overall aesthetic and functionality of the roof.

The other options do not accurately reflect the primary function of lath. While it can be involved in reinforcing walls, its purpose extends beyond that. Lath does not provide insulation; insulation is typically managed through separate materials designed specifically for thermal performance. Additionally, lath is not intended to support the roof's load; that function is handled by the roof structure itself and its framing elements. Therefore, the role of lath is focused on providing a supportive base for finishing materials rather than serving as a structural element or an insulator.