Waltham Lime & Cement Co., Waltham, Ma., is increasing its stock of lumber products after changing its name to Waltham Lumber, effective June 1.

The company began in 1930 as a distributor of masons' and plasterer's supplies. It started adding other construction supplies, including drywall, in the 1960s and expanded to wood products in the 1990s. Lumber now makes up a large portion of its business.