Johnson Contractors as well. Founded in 1918, Johnson Contractors is a general construction company that specializes in industrial plants, office buildings, apartments, commercial projects, schools, medical facilities, and water and sewage treatment plants. Its capabilities include heavy equipment installation, structural steel erection, concrete pouring, carpentry, excavation, and maintenance. The company is active throughout the Southeast. Johnson Contractors is a part of the Johnson family of companies, which also includes J. K. Johnson Mechanical Contractors and Johnson Electric Company.