Tinhouse, Old Castle Tinplate Works

The Tinhouse, located at the Old Castle Tinplate Works, is a significant industrial building from the 19th century. It is positioned between the Hot Rolling Mill and the Assorting Room at the eastern end of the site. The building is partially hidden by a later office range to the north and various corrugated iron sheds to the south. Its construction features rough rubble walling, with a roof made of corrugated asbestos and slate, topped with a distinctive ridge clerestory. The north-facing elevation has five blocked segmentally arched openings with yellow brick heads beneath the eaves, while similar blocked openings are arranged in two tiers on the south side. The office range, built around 1960, is made of brick but appears to be constructed on the rubble plinth of an earlier building.

The original layout of the Tinhouse remains largely intact, featuring six tinning bays on each side. Each bay is supported by a heavy iron lintel and has a segmentally vaulted brick ceiling, with a central wide tapering rectangular chimney that is truncated at the roof level. Each bay includes small blocked windows on either side of the hearth, and one bay still has parts of the original pulley mechanism. Two bays in the south range have been damaged due to the removal of chimneys, and three bays on the north side are partially bricked-up. A blocked segmentally arched doorway in the center of the west wall once provided access to the Hot Rolling Mill, while sliding doors in the east wall lead to the Assorting Room. The roof is supported by light steel trusses.