Industries in the Special Trade Contractors subsector engage in specialized
construction activities, such as plumbing, painting, and electrical work. Those
establishments that engage in activities primarily related to heavy construction,
such as grading for highways, are classified in Subsector 234, Heavy Construction.
The activities of this subsector may be subcontracted from builders or general
contractors or it may be performed directly for project owners. The
construction work performed may include new work, additions, alterations, or maintenance and repairs. Special trade contractors usually perform most of their work at the job site, although they may have shops where they perform prefabrication and other work.