Microscopic view of saltpetre on a damp wall

How to remove saltpeter?

It is common for dampness to be one of the most popular problems experienced by a property, particularly in relation to facades and internal wall surfaces.

Saltpetre is one of the many ways in which dampness manifests itself. It is important to note that this is a type of discolouration that can indicate that a house or structure has a deeper moisture problem that needs to be addressed effectively.

What is saltpeter?

Saltpetre on walls is capillary moisture in the form of whitish discolouration, which results from the formation of crystallised salts. The reason for its appearance on facades and wall structures is related to problems of capillary rise in a building from the ground and the foundations of your house.

This rising damp attracts sodium salts from the soil and walls before crystallising on the surface. The problem of saltpetre is not merely cosmetic, as it can also be the source of more serious problems, which are difficult to combat with a simple dehumidifier. By lifting the wall covering and leaving behind a wall completely unprotected against rain and sun, it facilitates the development of cracks and gaps.

However, rising damp spreads quickly from elsewhere. If a wall surface shows discolouration due to saltpetre, it is very likely that within a short period of time the moisture will rise to the surface and cause material damage to the installations it houses, such as damage to pipes or electricity.

Nico the apprentice handyman | The Saltpeter - NLAB #6

Identifying the origins of saltpeter: an important step

Whether or not a structure has saltpetre stains depends on the components used in its foundation and their ability to protect and shield. Considering all the complications that can cause saltpetre and rising damp, the first step in removing saltpetre and damp is to determine :

  • The characteristics of the area to be treated.
  • The type of damp and its source, so that the problem is not simply treated superficially, but the necessary steps are taken to tackle its roots.

After this initial analysis, the choice of products to remove saltpetre from walls will not only be simpler, but also more effective. As we have pointed out on other occasions, detecting the origin of the damp is the key to avoiding the deterioration of a house and to ensure the most appropriate treatment to enhance the visual appearance, but also the protection and restoration of a building.

How to remove saltpeter?

Once you have identified the composition of the structure to be treated and its condition, you can choose the right products to remove the saltpeter. For this purpose, there is a wide range of products available for the protection, treatment and renovation of moisture-related problems on fabric. However, you will need to clean the area first.

To achieve this, you must :

  • Using a stiff-bristled brush, brush the areas covered by the saltpetre with hot water. This is essential as it removes the crust that has formed with the saltpetre. If necessary, do not hesitate to use a detergent or soap to help clean the area.
  • Rinse the wall with clean water.
  • Apply a mixture of hydrochloric acid and water with the brush. This mixture of 0.1 litre of acid to 1 litre of water should be left on for 5 to 10 minutes so that the acid can remove all the saltpetre.
  • Rinse the area again with hot water and if necessary scrub off any remaining saltpetre residue from the wall.

Now that the saltpetre has disappeared, you need to treat your wall to prevent it from reappearing. For this purpose, we recommend Rubson Wet Wall Treatment. This is a very reliable product for use on internal wall structures and damp walls that require regular treatment. It is a very reliable coating.

Its advantage: The product's water-based, solvent-free formula combined with a milky white acrylic resin gives it a colourless finish once dry. It is in fact the ideal type of coating to treat wall structures on ground floors, basements or warehouses where condensation and lack of air circulation generally exacerbate moisture problems.

Do you prefer to use a professional? If so, please follow the link below. You will be put in direct contact with a professional who will be able to offer you a quote (without obligation and FREE).