The Grey Chalk Project at the SPAB Working Party  

Manifest were present at the recent Working Party, organised by the Society for the Protection of Ancient Buildings, at Boxley Abbey in Kent.  We are part of the ongoing Grey Chalk Project, in which a local chalk is burnt in field-kilns (pictured), to create a feebly hydraulic lime mortar when mixed with local sands and aggregates.

Although the island of Britain is very rich in limestones, no naturally hydraulic limes are produced to any commercial scale in this country.  In particular, the weaker hydraulic limes are very difficult to source, and yet they accounted for much of the building work in London and the Home Counties throughout past centuries.  Our work at Boxley is ground-breaking, and with successful in-situ trials, we hope that this marks the beginning of much further work with these local materials.

This is part of our ongoing Local Materials Initiative, encompassing lime, timber and much more.