Threshing Barn at Tre-castell Farm

A large shed open at the E side except for 4 tall cast-iron columns. Stone walls of local limestone masonry, uncoursed; slated roof. The main roof consists of 4 bays plus hipped end bays; the N end bay is storeyed and separated by a stone cross-wall, the space beneath the 4 common bays and the S end bay is unencumbered.

The N end-elevation is symmetrical with 2 storeys and 2 windows. Aligned doors centrally above and below, the upper door semi-glazed and serving as a window, the lower door with an overlight. Four-pane sash windows above and below. The S end-elevation is plain but with slits for ventilation or for the power drive.

At the W side is a lower range of buildings converted to domestic use, with a slate roof continuing the slope of the barn roof but with one large gable and 3 small gables (plus one in the north flank). Three doors and 5 windows below, one window to each gable above; all the windows of sash type with 4 panes.

The trusses are of superior design in mixed timber and wrought iron, with a timber collar beam and struts, an iron king tie and iron ties to the feet of the rafters.