Mortars, Renders & Plasters

Historic England summarise the use and history of mortars, renders and plasters:

" The plastic quality of mortars offers great versatility, from binding regular or irregular stones or bricks, to lining flues or forming utilitarian floors, to modelling of virtuosic decorative plaster or render, often embellished with paints.

For centuries the composition of mortar, renders and plasters in England was based on raw materials largely derived from local geological resources, and modified by organic and inorganic additives to suit specific needs.  During the Industrial Revolution, however, natural and artificial cements were developed, which provided a quicker set and greater compressive strengths.  These properties were inherently different from most traditional construction materials, a fact that was already recognised in the C19.  The artificial cement industry prospered as lime production declined.  It was only years later that it was realised that a great deal of damage to historic fabric had been caused by the use of modern cement binders.

To resolve this problem, a concerted recovery of the lime-based tradition began in the late C20.  A welcome commercial response has been the production of a broader range of lime mortars, each with specific potential. Understanding historic materials and their modern counterparts is vital in selecting appropriate materials for conservation projects."

We are experienced in lime mortars, lime renders, lime wash, lime plasters and limecrete floors.