Clay binds pollutants and odors

With the moisture, clay also stores odors and pollutants. It breaks them down or ties them in firmly.. 

One gram of loam minerals has a surface area of about 800 m².


A great advantage of clay as a building material is its openness to diffusion. This means that it is able to regulate the humidity of the room air. With the water molecules, it also absorbs odors and pollutants and is able to store them too firmly or even to separate them again. 
The clay, an important component of the loam, has a special crystalline structure: it is multilayered. There are strong capillary forces between these layers, through which the water and the substances bound in it can reach the deep layers of a massive clay wall. The crystal structure is so fine and multi-layered that one gram of the clay mineral has a surface area of around 800 m² - and with just nine grams you have the area of a football field: many opportunities for water molecules to accumulate. 
It is one of the truisms of earth building: the more earth there is, the more potential the earth wall has to absorb moisture or, for example, to store heat.
Fire smoke, smoking or vapors from the kitchen and bathroom: All these smells - or the fine dust from fire or cigarette smoke - can be absorbed by clay plaster with the steam, which is created naturally through sweating and breathing. It cannot replace regular ventilation, but - with a sufficiently large wall surface and thickness - it buffers these vapors and odors: Steam penetrates the capillaries for as long as there is excess in the room. If there is a lot of steam, this process continues until the first water molecules have reached the outside of the wall and are dried away by the wind: a capillary suction is created. If the steam is completely absorbed from the room air, the process comes to a standstill.
And we've tried it and it's true: clay has self-cleaning powers. We removed a nicotine-contaminated clay wall and put the clay aside. It actually cleans itself. After a while the stench was gone.


                                                     to the clay topcoat plaster