The Building Conservation Directory 2024

71 CATHEDRAL COMMUNICATIONS THE BUILDING CONSERVATION DIRECTORY 2024 ROOFING 3.1 and could be made out of whatever materials kept the wind and weather out of the house. This included wattle and daub, turf, clay or rubble. A window was simply a hole cut into the wall and covered with a wooden shutter. Today, there are few cruck frame houses remaining. Much of the information we have now was collected through excavations by archaeologists and writings or drawings from the past. FOUNDATIONS AND FLOORS Earthen foundations and floors were common in vernacular buildings. Sometimes the earth was tempered with clay or silt, which was done by ‘puddling’ or compacting the ground by foot, or by stalling animals to trample down and level the floor. Other variations found include ash, clay and dung, and sometimes imported materials like chalk or gravel are found. Generally, this surface was then covered with rushes and herbs to prevent dust rising from the surface. Mortar or ‘lime-ash’ flooring was also found in all status of building between the 16th and 19th centuries. Lime-ash is generally a form of gypsum plaster which is supported and applied to reeds, straw or timber laths which in turn are laid over rammed earth in a solid floor construction at ground level, or on timber joists and timber boarding for a suspended floor on other levels of a building. Timber piles were also used in foundations to provide stability in softer ground. This was particularly common in crannogs (houses built on jetties over a lake). The piles were driven down past the soft strata and into good ground that could support the load of the building. WALLS Earth and clay walls were common up until the mid-19th century. The material was widely available, easy to work and durable. Forms included: Mudwall earth mixed with straw and laid in lifts or courses between 15–55 cm. Found in areas where the soil contains a good proportion of clay. Clay and bool a mudwall with rounded stones in courses between the earth and straw mixture. Claywall a mudwall mixed with stones and placed between shuttering. Turf earth blocks used on their own or with alternating courses of stone. A herringbone pattern could add strength. Shuttering clay or earth, and any natural aggregates, formed between a shuttering of timber. Wattle and daub clay combined with timber wattle to create thin panels in timber-framed walls. The earliest type of stone wall built in Scotland was the drystane dyke or dry stone wall. Courses of stones are positioned directly on top of each other without mortar, relying on gravity and friction between the stones to hold everything in place and provide structural stability. Each stone is laid to maximise friction, ensuring that it makes the greatest possible surface contact with the greatest number of stones around it. Courses are built so that in each successive layer the vertical joints between stones are staggered, thus ensuring that the weight of every stone in the face of the wall is shared between those lying immediately below it. The overlapping weights of the individual stones, and their skilful placement effectively knit the structure together as the wall slowly settles with time. In the past, walls would have been built with stones found close to the construction site, either as surface stone from field clearance, or extracted by hand from small quarries nearby. Walling traditions differ from place to place depending on the quantity and types of stone available, with local geology dictating the shape and size of available stone, as well as the workability of the material. Common forms include: Single wall one stone in thickness, commonly constructed of boulders and large stones. Double dyke two parallel stone walls, the void between filled with hearting of smaller stones or organic material knitted together by throughstones, topped with flat coverstones and copestones. Rubble stone masonry was also used for walling. This technique uses pinnings, or small stones, to secure and fill the gaps between larger stones in the wall. Lime or clay mortar is used throughout to bed both the large stones and the pinnings. Rubble walls can be constructed in many different ways. The stones can be laid in even courses or randomly (coursed or uncoursed), dressed and squared, or used as they are found. A drystane dyke – the earliest form of masonry walling in the UK: courses of stones are positioned directly on top of each other without mortar, relying on gravity and friction alone Survey drawing from the Canmore collection showing the construction of a 19th century cruck-framed Cottage at Torthorwald, Dumfriesshire (Drawing: crown copyright, Historic Environment Scotland, http://canmore.