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.
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:
- Flat Plastering in Traditional Buildings
- Lime and Cement Mortars in Traditional Buildings
- Repointing Ashlar Masonry
- Repointing Rubble Stonework
- Restoration Mortars for Masonry Repair
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
Other sources of information and support are available, and Carmarthenshire County Council does not specifically recommend 1 source of advice and information over another.