Building record SBT 013 - Former Roundhouse at Mill House

Post mill with roundhouse, demolished c.1922. The roundhouse remains as a store. There were four patent sails, two pairs of stones in the head and a fourtail (S1). Earliest cartographic evidence is 1736 (S2). Visible on the 1st edition OS map (S3).

A windmill stood here at the time of Kirby’s Map of Suffolk in 1736 and possibly for many centuries hitherto as the land belonged to nearby Sibton Abbey, which is known to have possessed a mill somewhere in the parish. The red-brick roundhouse is an addition of the early-19th century designed to raise the sails higher into the air and to provide supplementary storage space for grain. It was originally a free-standing circular, single-storied structure with a conical roof and four curved internal piers or buttresses designed to support the ends of the massive horizontal cross beams which supported in turn the central post upon which the separate timber-framed superstructure (or buck) revolved with the wind. The buck was reached by an external ladder and would not have been accessible from the roundhouse. The latter contained two opposing doors to the east and west, ensuring access whatever the position of the sails, with windows to the north and south. The buck is understood to have been demolished in 1922, and is shown in a photograph of 1921 but not on a postcard dated 1933, after which the roundhouse was converted into a mill in its own right by raising its walls slightly and inserting a loft lit by four new upper windows. Within a few years of this conversion a lean-to shed of corrugated iron was added to its western wall to serve as a granary and a boarded chute was cut into the brickwork to allow flour to descend to the exterior from the milling loft. A pair of composite stones that survive in the nearby garden may have stood on this loft, powered either by an internal diesel engine or by an external drive from a nearby engine shed (originally built between 1882 and 1903 to contain a supplementary steam engine). During the 1950s milling was transferred to a new cementblock shed to the south of the site and the roundhouse was converted into a piggery with new cement-block additions to the west and north. At some point the eastern door was moved slightly to the south of its original position and lowered to accommodate a new window immediately above. In recent decades the conical roof and loft have been removed and part of the northern wall demolished (S4).