What is the purpose of wire lath on exterior walls?

• A. Provides an anchor base for plaster and reinforcement
• B. Provides insulation
• C. Supports electrical wiring
• D. Reduces mass

Answer: (A)

Wire lath on exterior walls acts as a mechanical anchor and reinforcement for plaster. The mesh provides a rough, keying surface that plaster can grip onto, creating a bond that holds the coats in place and distributes movement and stresses across the wall. This helps prevent cracking and detachment from wind or settling, giving the stucco system durability. It’s installed as a base for the plaster coats (scratch, brown, finish), rather than for insulation, electrical wiring support, or reducing wall mass.