Clay is a fine-grained material, consisting primarily of hydrated silicates of aluminium.  Since ancient times it has been used to make bricks, tiles, pottery, art objects, and musical instruments. It is used medicinally for both internal and external detoxification and has been known for centuries for it’s anti-inflammatory qualities.

The use of clay as a building material:

Clay has been a primary material in the construction of houses since time immemorial. This can be in the form of rammed earth or cob, bricks (baked or sun-dried know as Adobe, made of clay and straw) or plaster.
Mixing clay (bonding agent) with sand (filling agent) makes clay plaster, which is a 100% natural building material. Depending on the content of the clay, clay plasters can appear in a variety of colours, from white, through green and brown, to red. Adding pigments can vary the colour.

Clay plaster:
In general we use two types of clay for plastering.
Clay mixed with fine sands in a large range of colours, which are applied in a thickness ranging from 2 to 4 mm. As decorative additives we can use mother of pearl, basalt, glimmer, different types of straw etc. To see an example of this type of plaster, click on Clay Finish in the Lartierra gallery.
The second type of clay plaster is made up of a larger grain of sand and thicker straw and thus, needs to be applied in thicker layers, 5 mm or more. The thicker mix of this plaster eliminates inequality in walls. The flexible nature of it lends to fantastic shaping possibilities, e.g. arches, niches, alcoves. A thicker layer of clay has a better effect on healthy atmosphere of the room. Objects, such as stones, shells, pieces of glass or tiles etc. can be inserted into it as decoration. This type of clay plaster is normally found in natural colours, usually brown or red (see gallery- Clay Base).
In both instances the surface can be smoothed with a trowel or left in a rougher organic state. In the second instance, a round stone can be used to achieve a final ripple design or a carving chisel or trowel can be used to sculpture the desired shape. These clay coats can be applied on any stable absorbent surface with the exception of wallpaper.

Some advantages of clay:

Clay has a breathable surface, which regulates both humidity and temperature. By absorbing moisture it makes rooms more tolerable in humid weather. When the air becomes drier it releases moisture into the room helping to improve the air quality.
Wall surfaces remain cool in summer and warm in winter.
People with respiratory tract problems find relief as dust particles are kept down and do not circulate in the air which can cause an allergic reaction, as often happens with most synthetic plasters.
Clay neutralizes the electromagnetic field, which has a negative effect on all living beings.
It has minimal impact on nature, is energy efficient significantly lowers pollution levels in the production stages and creates a healthy environment for the inhabitants of a house.
If needed, it can be removed from the walls and reused as a new plaster or building material, or spread on the soil for cultivating plants.