Expamet Building Products, part of the Birtley Group, was established in 1889 in Hartlepool as the British Metal Expansion Company.

The British Metal Expansion Company had sole European rights for the manufacture of expanded metal mesh, mainly for use as reinforcement and lath in the rapidly expanding sector of concrete construction.

The business that grew from these early days later changed its name to Expamet.

Platinum Chemicals are suppliers of Expamet Products, such as Expamet BAT Splice Plates.