A novel approach to achieving airtightness in drylined load-bearing masonry dwellings

This paper describes a novel approach that can be used to construct airtight drylined load-bearing masonry dwellings. This involves the application of a thin layer of ‘parging’ to the internal blockwork leaf of all external walls. Whilst this approach has so far only been undertaken on a field trial using one dwelling, the results suggest that the application of the parging layer improves the airtightness of the dwelling substantially and air leakage rates of less than 5 m3/h per m2at 50 Pa can be achieved. The paper also identifies a number of additional measures which, if undertaken, could reduce the air leakage of this dwelling even further. Practical application: Airtight construction techniques are increasingly required in order to comply with Part L of the building regulations. Wet plastering is very successful in reducing air leakage through load-bearing masonry construction but is rarely used nowadays because of its longer drying time compared with drylining. The novel approach described in this paper provides the advantages, of both systems by applying a quick-drying airtight barrier before drylining.