What is saltpetre?
Saltpetre can often be observed on old masonry, whitish residues form here, which sometimes remind you of mold, but have a solid structure. What exactly happens when saltpetre forms and what is it made of?
On older walls there are sometimes white deposits that sometimes remind you of the appearance of a stalactite cave and sometimes how Mould works. That is saltpetre.
How is saltpetre formed?
- The origin of the word already reveals something about the term, because it is composed of “sal” for salt and “petrae” for rock. So it is a mineral that occurs naturally in solid materials.
- Saltpeter is formed when other substances are decomposed, for example calcium nitrate (the classic masonry nitrate) or sodium nitrate, a chemical compound with sodium. In the process, nitrogen-containing substances are broken down, such as algae, animal feces or certain dead bacteria that can ultimately be found anywhere.
- The white coating is created when this is added humidity comes, which dissolves individual components from the organic deposits, such as calcium, in order to then deposit them on the outside of the wall. Because when the water droplets leave the wall, they evaporate, leaving only the white deposits.
- Between the lime A chemical conversion reaction takes place in the masonry and organic substances, the results of which can be seen on the outside.
- Potassium nitrite, a special form of nitric, is poisonous, but since the deposits are not released into the room air, the phenomenon is considered harmless.
Remove saltpetre in the basement - this is how you eliminate the causes
Saltpeter is characterized by unsightly white edges of a crystalline structure ...
What can be done about saltpetre?
- If you see saltpetre on the walls, it could be other salts that just look similar. For example, mortar in masonry, which regularly comes into contact with moisture, can also be decomposed and rinsed out. This looks very similar to saltpetre, but it is dangerous for the building fabric as it becomes porous.
- So whether it is saltpetre or not is not so easy to see optically. The deposits are usually found where there is also a lot of organic material, for example near Barn buildings that come into contact with the urine of animals or those that were previously used for agriculture Plots.
- If you just scrape off the saltpetre, it will come back quickly. It is therefore important to eliminate the cause, i.e. the penetration of liquid into the wall. This can be done by sealing, special drainage or the application of sealing paints.
How helpful do you find this article?
