Thomas Armstrong has muscled its way into being one of the leading aggregates producers in the UK. Thomas Armstrong Holdings Ltd. also makes custom joinery, concrete blocks, and prestressed concrete (flooring, stairs, and panels) and operates a general construction business (residential, commercial, and industrial) and a timber division. Thomas Armstrong, a joiner, cabinetmaker, and wheelwright, founded the business in 1830. A century later the firm converted to a limited company. It has grown through acquisitions of companies such as ACP (Concrete) Ltd., William Rainford Holdings, Barnett's, Robinson's Concrete, and Tayban Developments. Thomas Armstrong has about 15 locations across the UK.