The Use of Lime

Lime is an essential component of the majority of renders, plasters, mortars and washes suitable for use on traditional buildings.  It was used on almost all construction projects up until 100 years ago but since World War 1 has been slowly replaced by Portland cement, plastic paints and gypsum plasters.

Importantly, unlike many modern products, lime based materials let structures ‘breathe’.  The breathable nature of lime helps maintain the building’s equilibrium, controlling moisture and dampness, leading to health benefits, improved internal comfort and protecting the building’s fabric from damage.

If you are undertaking any repairs to a traditional, solid walled building a good builder will recommend using a lime based material.  This could include a lime render or a lime roughcast for an external finish, a lime mortar for pointing, a lime plaster for an internal surface or Limecrete for the floor.  A lime wash, which has a soft looking finish, can be used internally or externally.  A lime plaster is traditionally mixed with a sand, but increasingly materials such as hemp or cork are being incorporated into the mix for a more energy efficient plaster.

 

Have a look at the Welsh Traditional Buildings Forum contractors’ directory to identify a builder who is familiar with using lime.

 

Below are some free sources of information about lime and how to use it. 

Ty Mawr, based in Brecon, are a company which supply many lime based materials.  They also have an extensive online knowledge hub with information about Lime 

 

Historic Scotland have produced a series of Leaflets called the INFORM Guides and whilst the examples are from Scotland, many of the techniques and materials employed are also relevant to Wales. 

INFORM Guides specifically relevant to lime work repairs include:

 

The Society for the Protection of Ancient Buildings (SPAB) produced publications on the care and repair of old buildings and have produced a detailed Briefing entitled Lime

 

Cadw have produced some basic guidance on Repointing in Lime and Patching Lime Render.

 

Other sources of information and support are available, and Carmarthenshire County Council does not specifically recommend 1 source of advice and information over another.