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Monument protection: Nano coatings for mineral and porous surfaces

Under the pressure of millions of years rock is formed. Man has turned stone into a cultural work of art. What was built for decades or centuries can be maintained with the most modern nano coatings from nanoCare. So that culture is preserved.


Keeping buildings young

Sandstone and limestone were popular building materials for many centuries. They can be easily cut into precise blocks that can be bricked up into magnificent buildings of all kinds. Built this way, many buildings have defied the weather since Roman times - until coal dust and car exhaust fumes made the rain sour. Today, the rapid decay of historic buildings is viewed with concern in many places. But there is a solution: Nano coatings not only seal porous building materials, they also protect them from chemical attack.


The enemies of mineral and porous surfaces

Mineral and porous surfaces have three main enemies:

  • Water
  • Frost
  • Acids

Water alone does not make much difference to a facade of limestone or sandstone. The eroding effect of rain is only minimal. However, this is provided that the rainwater is properly drained off via gutters and pipes. If a rainwater pipe leaks and water constantly runs down the wall of the house at a certain point, even the hardest stone will quickly leave a visible trace. In this case, no nano-sealing will help, but only a intact drainage of the rainwater.

If the pH level in the water rises due to soot, carbon dioxide and other exhaust gases, then even normal rain can clog a façade. "Acid rain" has only a slightly increased pH value. But this is sufficient to dissolve mineral and porous surfaces. As soon as the acid rain has created tiny capillaries, water can penetrate and remain in the surface. Then all that is needed is a cold night of frost. The water expands to ice when it solidifies and bursts open the facade more and more. There is no need to worry about the structural statics, because this process tends to take place in the millimetre range. However, over the years, the facade will become increasingly unattractive.

Especially strongly structured surfaces, such as sand-lime facing bricks with a broken outer edge, lose their characteristic appearance. In addition, the capillaries are ideal attack points for mosses and lichens. Although these do not destroy the building structure, they do give the facade a very dirty, weathered and unkempt appearance.

Sealing mineral and porous surfaces

To protect a façade from progressive weathering, a coating of sealant is the best option. This is especially true for historical buildings where plastic or metal paneling is not an option. There are two approaches for sealing facades:

  • epoxy resin
  • Nano sealing on SiO2 basis

Epoxy resin consists of two components. Depending on the mixing ratio, the resin becomes thicker or thinner. After curing, the epoxy resin creates a closed surface. It is available in all colours. This allows painted facades to be sealed and repainted in a single operation. Epoxy resin is sprayed on. In its liquid state, it penetrates into the capillaries of the masonry.

Thus it not only holds very well to the wall due to a sustainable anchoring. It also creates a closed, air- and watertight surface. On the outside, clear epoxy resin darkens the surface a little and creates a shiny effect.

His use should be chosen with care. Epoxy resin is sensitive to UV light. Under constant exposure to sunlight it becomes cracked and cloudy. Its renovation is extremely difficult and usually does not work without damaging the building fabric. Epoxy resin is therefore mainly suitable for interior use. It is very popular for sealing concrete.

Silicon-Oxide is basically nothing else than normal, extremely finely ground sand. To create a waterproof surface, this sand is mixed with silicone slurry. The rubber-like material is so thin that it can also penetrate deep into the capillaries, allowing mineral and porous surfaces to be sealed up to a depth of 2 cm.

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Seal mineral and porous surfaces: Technology and approach

The nano coating for mineral and porous surfaces is sprayed on or applied with a tassel or lambskin roller. However, this requires some preparatory work. First of all, the facade is cleaned thoroughly with a high-pressure cleaner. This also removes the remains of moss, lichen, old paint and other dirt. The remains of an old nano sealant are also removed during this process. This way you get a fresh, mineral and porous surface again, which is ready to receive a new nano coating.

In the second step the area to be coated is dried. It is very important that no water is "trapped" in the building structure. 

Otherwise, it can cause mould to form on the inside. A little residual moisture cannot be avoided, but the surface should be as dry as possible. The correct timing of a facade sealing is therefore also important. Warm spring or summer days are ideal, as the building is guaranteed to be dry during this time.

The coating is then applied to the facade in several layers. It is important that really no corner is overlooked or forgotten. Only a closed nano-coating consisting of Nanoflex TPM 300 as a primer and Nanoflex AG 1-4 as stain protection guarantees that no more water can penetrate the building structure.


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Stop the ravages of time with nano-sealants from a specialist

You see, renovating a facade is a matter for professionals. Do you have questions about nano sealing? Give us a call or write us a message.