We have just finished a series of mortar analyses at Hobcroft Barn, one of a number of isolated field barns on the Warslow Moors. Hobcroft field barn with visible from Dale Mine was built in the first half of the 19th century of traditional materials, with limestone and gritstone walls, gritstone and sandstone quoins and Staffordshire blue tiles. It has a number of original internal features including a hayloft and near complete boost with wooden boskins. The original building mortar mix is likely to have comprised of slaked lime; crushed waste, under burnt lime; ash from nearby industrial processes; and a small amount of fine sand and shale contaminants. The exact proportion of active lime binder is unknown, but from historic precedent, it is likely to have consisted of one part lime to perhaps two parts ash and inert lime. Some of the active calcium hydroxide reacted with the fine ash particles, and perhaps some of the iron content, to create a weak hydraulic lime mortar.