TECHNICAL BULLETIN
ISSUE 41
SEPTEMBER 2022
LIME MORTAR HISTORY WITH CASE STUDIES BERNIE SMITH MCABE, C.BUILD E, FCIOB, SMITH BUILDING SERVICES
In this article, Bernie Smith MCABE, C.Build E, FCIOB reviews the past use of lime mortar and explains the different types available and their benefits. He also shares two interesting case studies where he was appointed a consultant and his company, Smith Building Services, carried out repairs using lime render on historic buildings. History
began, but it is documented that the Roman architect Vitruvius provided basic guides for using lime when building. The Romans were keen advocates for using lime mixed with baked clay or volcanic ash, which when water was added, they found would harden considerably, producing a very reliable building component.
Limestone or calcium carbonate (CaCO3) is a naturally produced stone found extensively throughout the world. The earliest documentation of the use of lime in construction was around 4000BC. It is documented that the Egyptians used lime in the construction of the Pyramids. There is also some evidence of the use of lime when looking at buildings by the Romans and ancient Indians, and confirmation that lime was used when building the WeIzmann Institute in Israel, 12000BC.
Lime continued to be used as a reliable construction material through time, however, in the 18th century, it was discovered that if you fired a limestone that contained clays, this would result in a hydraulic lime. In 1756 a gentleman named James Smeaton developed probably the first commercial hydraulic lime product available on the open market. His method was to combine pozzolans and Blue Lias limestone which contained clay, and he discovered that this produced a strong lime mortar that was very good
All these years ago, it was discovered that if you burnt limestone and then combined it with water, pliable material that hardened with age was produced. There is no definite date affirming when regular use of lime in construction
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