Mortars: materials, mixes and methods

Mortars: materials, mixes and methods, a guide to repointing mortar joints in older buildings is an essential resource for anyone wishing to repair older stone or brick buildings in Australia. Written by David Young OAM, an acknowledged expert in the use and application of traditional mortars, and supported by the heritage councils of each state, it covers everything you need to know about working with lime mortars. 

Lime was the principal binder in mortars and plasters of Australia’s early colonial buildings, and it continued to be used in domestic construction until the mid-twentieth century. However, major changes in building practices after World War II led to the predominant use of cement in mortars. This change led to a decline in understanding of the properties of lime mortars, their important role in porous masonry, as well as the practical aspects of working with lime. This technical guide helps fill this gap. 

Part one is a primer, introducing key terms and concepts. 

Part two explores in depth the different mortar materials, mixes, binders, sands and aggregates and when they might be used, including an essential ‘Quick Guide’ to mortar mixes on pages 68–69. It also explains why the unthinking use of contemporary mortars to repair older buildings can cause long-term damage. 

Part three is the ‘how to do it’ part of the guide, covering the practical aspects of repointing – from the ‘when’ to the ‘with what’. Using the correct jointing tools and attention to the protection and curing of newly laid mortars are critical aspects of successful repairs.