California Lathing and Plastering Contractor (C-35 License) Practice Exam

Backing for welded-wire fabric lath must satisfy both the material standard and proper installation. Complying with UU-B-790 ensures the lath backing has the right properties—such as composition, coating, thickness, and performance—so it provides a solid key and bond for plaster. Being securely attached guarantees the lath stays in place during plaster application and curing, preventing movement that would create gaps, misalignment, or cracks. Together, these requirements ensure a durable plaster base. If only one aspect is met, the system can fail: noncompliant material may not bond or resist moisture, while loose lath can detach or shift, compromising the plaster.