Welcome to Plasterers’ Local Union No. 31. We proudly represent plastering employees and shop hands throughout 31 counties in western Pennsylvania.

Local Union No. 31 belongs to the Operative Plasterers’ & Cement Masons International Association (OPCMIA) of the United States and Canada, AFL-CIO. As the oldest building and construction trades union in the United States, the OPCMIA’s history began in 1864 when an organization known variously as the National Plasterers’ Union or the National Plasterers’ Organization started to unify the various local craft unions that represented workers in the trade. Local Union No. 31 was chartered by the National Plasterers Organization on February 22, 1887.

In partnership with our signatory employers, Local Union No. 31 continues the nearly 150-year tradition of providing skilled craftsmen and craftswomen to our customers at competitive prices. We ensure every job is done right the first time, every time.