The advice note describes:
- the performance requirements and essential properties of consolidants in general
- the scientific theory underpinning the use of nanolime
- factors that might limit the effectiveness of nanolime
- the best ways to assess the suitability of stone for treatment with nanolime
- how to apply nanolime
Although the past ten years have seen an increase in the use of nanolime as a stone consolidant, not much was known about its properties and performance. There had been no long-term evaluation of its effect on deteriorated limestone in an external UK environment. Furthermore, there was no consistent guidance on how to apply nanolime.
For these reasons, Historic England commissioned a programme of research at the University of Bath and site trials at various English cathedrals. The information provided in the advice note is based on both the results of the research and the experience of conservators who have used nanolime. It also reflects issues discussed at a symposium held at the University of Bath in September 2015.