The roothouse was built in the early 1860s and was the last building to be erected at Leighton Farm, the model farm of the Leighton Estate, developed after John Naylor had acquired the Leighton Estate in 1846-47.

The roothouse consists of two parallel, single-storey ranges with vaulted tunnels beneath, constructed of brick on a random rubble basement, with roofs of slate on the outer pitches and corrugated asbestos-cement and glazed panels on the inner pitches. The south gable ends face the road and have wide round-headed doorways (the doorway to the right has later been lowered) with raised original vertical sliding gates in front of inserted sliding doors. The east side wall has ventilation holes in lozenge patterns and an inserted door at the south end. The north gable ends also have ventilation holes laid out in lozenge patterns. In the random rubble basement wall beneath, are openings to six brick-vaulted tunnels (one now concealed by an inserted door).

Internally is a row of central posts, between which has been infilled with concrete blocks at a later date, dividing the interior into two units. The west range has a roof with king and queen posts and raking struts. The east range is said to have a sloping cartway, while the west range has a modern concrete floor but the shafts through which the roots were passed can be seen in the vaulted tunnels of the basement.
9source; Cadw listing database) RCAHMW 10th November 2008