Lime mortar has been used for thousands of years in construction, and many houses in the UK prior to the 1930’s were built using Lime.

Lime mortars and plasters as apposed to modern cement and gypsum plasters are recommended in older buildings due to their vapour permeability or ability to let the building ‘breathe’. This reduces the risk of water ingress, trapping moisture within the masonry and causing subsequent damage to the fabric of the building.

Lime mortars and plasters are more porous and assist in stabilising the internal humidity of a building by absorbing and releasing moisture. This in turn, reduces surface condensation, damp and mould growth which is a prevalent fixture in our modern society.

Today we are seeing many issues with traditional masonry due to repairs made using modern mortars, plasters and paints. Towards the end of the 20th century, cement came into fashion and many traditional houses were repaired in this way. We are only now starting to see the damage that this product has caused such as spalling to the stone and brickwork and the resulting damp problems.

A return to traditional materials and methods is on the rise and is needed in order to conserve and restore historic buildings before they are lost forever! These days, knowing and understanding how to work with lime is a dying craft, with many companies advertising a knowledge of lime mortars yet opting for ready mixed alternatives which can in fact be just as damaging to a historic building as cement based mortars. This comes down to lack of knowledge and skills in the techniques of heritage building that can only really be gained when working alongside a specialist for many years.

lime mortar

Why Use Lime?
Building Limes Forum

1. Lime Allows Buildings To Breathe
In the search by architects and conservators for building materials sympathetic to traditional construction, lime was found to be one of the most important. One of the reasons lime binders are promoted by the Society for the Protection of Ancient Buildings for repairs is because they are vapour permeable and allow buildings to breathe. This reduces the risk of trapped moisture and consequent damage to the building fabric.