The nature of mass masonry granite walling and the potential for retrofit internal wall insulation strategies

Traditional buildings constructed of solid granite walling that have timber framing with lath and plaster internal finish are not thermally efficient when compared with modern constructions. They are also termed ‘hard-to-treat’ as they need special care and attention to historic detailing, breathability and hygrothermal performance. These traditional buildings were originally constructed with lime mortar but during the period of mass Housing Disrepair Notices, many of these buildings were re-pointed using OPC-based cement/sand mortar. While the ‘whole house’ needs to be considered in any thermal improvement strategy, granite walling presents a particular characteristic which demands a different approach to that of sandstone or limestone walling when considering internal wall insulation. This paper explores the main issues to consider when contemplating a thermal improvement strategy from the material perspective. The buildings identified in this paper are in the North-East of Scotland.