LIKE-FOR-LIKE AND COMPATIBLE MORTARS FOR THE REPAIR OF TRADITIONAL BUILDINGS

Abstract. The subject of this paper is traditional mortar preparation and materials, particularly earth-lime and air or feebly hydraulic hot mixed lime mortars with particular emphasis upon British practice and experience, whilst stressing their international ubiquity historically. It will demonstrate their appropriate functional performance and attest to the need to use similar mortars, similarly composed and prepared, in the repair and conservation of traditionally constructed buildings. It will question how commonly modern Natural Hydraulic Limes may be considered to be like-for-like or of compatible strength and functional performance. The paper will draw upon extensive research into historic texts, as well as primary archive research into historic building accounts and the latest research into the properties of lime rich air lime mortars and NHL mortars.