Mortar Repair Frome, Bath & Surrounding Areas
Mortar is the material between the bricks or stone blocks in masonry walls, usually made of sand and water with a binding material added so that it sets hard. Before cement was introduced to the construction industry in the early 1800s the binder most commonly used in mortar was lime.
The root meaning of the word “lime” is “sticky substance”, and that is exactly what makes this material so well-suited for rendering and binding together historic stone structures. Its use goes back thousands of years – the Ancient Egyptians used a lime plaster to coat the pyramids at Giza.
Lime mortar is a durable, highly adhesive and workable mortar with a porosity that is not found in modern Cement. Being porous and permeable are properties required in old stone and brick masonry because it allows the building fabric to breathe, preventing condensation, damp and mould from pervading the interior.
We use lime mortar today mainly for undertaking repairs in the conservation of buildings that were originally built with it – particularly stone structures.
Here at Gorgon Stone we are passionate about conservation and restoration and have armed ourselves with all there is to know about the constituents and properties of lime mixes. We are able to analyse the original lime mortar used on an historic building and formulate a matching mortar that is an exact replica of the original, both in colour and texture.
There are basically two types of lime mortars – non-hydraulic (including lime putty), which hardens when exposed to air, and hydraulic, which hardens when mixed with water. Each of these types have sub-types. To undertake sympathetic and natural-looking mortar repairs on an old building requires a comprehensive knowledge of lime mortar and how it relates to historic masonry techniques.
Analysis of historic mortars has revealed that although the basic composition of lime, sand and water remained unchanged, there was great variation in the mix ratios and different types and grades of sand were used in different regions of the country.
Fortunately the Gorgon Stone team have extensive experience of masonry restoration projects involving mortar repairs, and we are regarded as leaders in the field in our home town of Frome, the nearby city of Bath and surrounding areas.
We mainly use non-hydraulic lime in the form of lime putty for conservation work. This comes in air-tight tubs covered by a layer of water and stays in a workable condition for months. The lime putty can be utilised as a base for creating limewash paint, making fine plasterwork, be used for pointing masonry, and making render.
Repointing an old stone wall with modern cement and sand mortar would not only be a difficult task, but the result would also be an eyesore! The new, hard cement would stick out like a sore thumb and directly affect the integrity of the structure, eventually resulting in decay and damage, because the chemical composition of cement is not compatible with old building techniques.
If you are lucky enough to own a stately old building which needs perking up with a touch or two of lime mortar, give Gorgon Stone a call and we’ll give it the make-over it deserves.
For free advice and quotations, contact us.