Paving stones are often found on paths, terraces or in the driveway. But even these durable materials suffer from dirt and water. We explain various methods of effectively sealing the paving stones.
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Seal or impregnate paving stones?
Although colloquial speech often speaks of sealing the paving stones , there are two completely different approaches to protecting the surfaces of paving:
When sealing stone surfaces, the actual material is surrounded by a protective layer so that dirt and moisture can no longer penetrate to the stone. As a rule, however, such a sealing is accompanied by some visible changes in the stone.
Impregnation, on the other hand, leaves the surface of the stone untouched, but closes the pores. Dirt and water can no longer penetrate deep into the material and settle.
The methods in practical application
Now it is a matter of putting concrete possibilities into practice:
Regardless of the method chosen, the first step is always to clean the paving stones. This is the only way to ensure that the selected product actually gets to the stone itself later and is not prevented by dirt and growth. Follow these steps:
- Remove existing growth by flaming or scraping
- Sweep the area with a street broom and remove loose dirt
- Loosen and remove adhering dirt with a garden hose and broom, alternatively a high-pressure cleaner
- Let the surface dry well
Variant 1: the Election
Changing the stone surface for better resistance properties is called silicification or – technically – silicification. The mineral components of the stone are chemically converted and converted into more stable substances, such as silicon dioxide. Although the process has a certain depth of penetration, it is still referred to as sealing, since the surface becomes denser and firmer in the first place.
|aqueous solution of different composition
|mode of action
|Hardening and compaction of the top stone layers
|Apply to the surface with a brush or brush
Depending on the product, spray application is also possible.
Wait until the manufacturer’s information has expired before using the surface again
|up to 20 to 25 years depending on product and stone
|no covering coating, but closure of the actual surface through chemical modification of the substance
Variant 2: the organic seal
The most common form of surface sealing today is certainly covering the paving stones with chemical preparations that form a protective layer. Both in the processing as well as in the later appearance, they often show a high similarity to paints.
|Aqueous to viscous liquids with oils, resins and other hardening and blocking ingredients
|mode of action
|layer-forming covering of the pavement surface
|usually applied with a brush, brush or roller
|10 years or more, depending on the product and use
|often increasing the color intensity and contrast of the stone; development of a matte gloss; optionally also active control of the color change by adding dyes and pigments
Variant 3: the mineral sealing
The sealing of paving stones with the help of mineral products usually only plays a subordinate role today. The reason for this is the significantly higher resistance and flexibility of organic seals. In addition, mineral coatings form a clearly visible cover and therefore often resemble a coat of paint.
|mode of action
|Layer formation against dirt and moisture on a mineral basis, eg cement
|Apply with a brush or broom as a viscous slurry
|by 5 years depending on use
|mostly complete covering of the stone surface; clear optical change; therefore, for example, also good for upgrading simple concrete block surfaces
Variant 4: the impregnation
Impregnations penetrate quickly into stone and are not or only slightly recognizable. However, you buy this preservation of the stone surface with a significantly lower durability, since impregnations penetrate quickly and deeply, but are also quickly rinsed out again.
|Aqueous solution with pore-closing contents, e.g. as oil, resin or other mineral compound
|mode of action
|Pore closure well below the stone surface
|apply with a brush, brush or roller,
|Depending on the product and exposure to dirt and weather, only a few years, usually a refresher every 2 to 3 years is recommended
|almost invisible; can be colored if necessary, but then the natural stone surface is retained; Maintaining breathability
frequently asked Questions
A blanket statement for or against sealing or impregnation or for individual methods cannot be made. Each variant has its own advantages, depending on the objective and demands. Modern sealing materials promise long-term peace, whereas preservation of the unadulterated appearance speaks strongly for impregnation.
No. Especially in the case of products that depend on a reaction with the material itself, this must also meet the requirements for this reaction. Therefore, use the product data sheet to find out exactly whether a preparation is suitable for your paving stones.
All products sold in Germany must meet legal requirements regarding their environmental compatibility. However, some substances are more critical, especially when it comes to application, while others are not. In general, the manufacturer’s instructions on protective measures and working methods must be followed in order to avoid problems for people, animals and the environment.