little processing and energy to produce. They include those
made of clay, gypsum, and lime. Clay and gypsum plasters are more delicate. They tend to be rather soft and water soluble and therefore they are reserved for interior work. Lime plaster is used in interior and exterior settings, providing excellent protection against the elements.
Clay plaster is pleasant to work with. Unlike gypsum or cement plasters, clay plaster offers a longer setting time allowing for a more relaxed work pace. It creates velvety finishes and warm environments. While clay is easy to repair, it can also be easily damaged – a downside to consider in high traffic areas.
Gypsum plaster is widely available in North America and when used indoors it can last a lifetime. The potential release of chemical additives into the air may affect air indoor quality for several years however. .Although relatively easy to work with, gypsum plaster sets up very fast and therefore may require more labor.
Lime plaster is the most durable natural plaster. It cures over time providing a hard limestone finish. As history shows, it can withstand hundreds of years of weather. Flexible, it is less prone to cracking as walls expand and contract due to temperature changes or variations in moisture levels. In addition lime plaster shrinks minimally when it drie, which reduces risks of cracking as well. Another advantage is that the alkaline nature of lime inhibits the growth of mold and mildew. Lastly it feels warm in the winter and cool in the summer –
thanks to a typical low thermal conductivity.