Lime Render Systems

A lime render in its simplest form is a render that contains only lime and a range of blended sands, fine aggregates and specific additives.

Lime render systems are more breathable and ductile than a cement based render and can be used on all masonry type substrates, but must be used when the building is constructed of lime mortar, for example Victorian or earlier type constructions, or when the substrates are earth based for example, cob, witchet, bungaroosh, adobe etc. 

Lime renders can be applied to cement mortar constructed structures too, such as concrete block constructed houses. 

There are lime render solutions to deal with below ground applications and to deal with salt petre situations, together with lime suction control coats, base coats and through colour top coats that can be both sprayed or hand applied. These systems can be finished in both the traditional trowelled, sponged, bagged finishes as well as scraped and textured finishes, which can all receive further ashlar detailing.13 

When Best To Choose A Lime Render System

If a building is constructed with a lime mortar, it should only be coated with a lime render system.

Applying a cement based render onto a lime mortar constructed building is detrimental to the fabric of the building, and will invariably crack. It then allows water to penetrate into the building fabric, which can also be affected by frost, and this causes further damage to the fabric of the building. In addition, a cement render has less breathability than a lime render which could lead to trapped moisture behind the render, which may result in the surface of the building breaking down as well as causing damp walls, mould and long term degradation of the property. This can also lead to an adverse affect on both the health of the building and its occupants. 

A lime render is also more sustainable than a cement render, which can help towards the reduction of carbon emissions, both in manufacturing but also in having the ability to capture carbon too.