Sealing natural stone
Whether indoors or outdoors, natural stone is one of the most popular floor coverings for good reason. However, many customers are reluctant to cover larger areas with natural stone because they cannot estimate the amount of care and cleaning required. We have put together the following detailed guide to sealing natural stone so that you know what to expect when sealing floors and what to look out for.
Sealing or impregnating natural stone?
Both protective treatments have their advantages and disadvantages. With impregnation, the treatment penetrates the pore structure of the surface. In contrast to floor sealing concrete, no layer forms on the surface. On the one hand, this has the advantage that the floor is non-slip afterwards and no footprints form on the surface, but on the other hand, a natural stone sealant offers the floor more reliable protection against environmental influences. On the other hand, floor sealing makes the surface easier to maintain and gives it a slight shine.
How do I seal my natural stone floor correctly?
We recommend our step-by-step guide to ensure that the natural stone sealing of your floor is successful the first time.
Step 1: In order for the floor sealing to be successful, all the necessary materials and tools should be obtained in advance. This includes a container for the sealing liquid, a brush for applying and spreading, rubber gloves and suitable clothing that can get dirty.
Step 2: Before you can start, you must first clean the natural tiles thoroughly and then allow them to dry thoroughly. The surface to be treated must be absolutely clean and dry.
Step 3: When sealing outdoor floors, it is advisable to check the weather forecast, as both wet and cold conditions before and after the treatment will damage the protective film before it can dry. The optimum temperature is 10 to 25°C.
Step 4: The floor sealant is then poured into a container provided for this purpose. You will need about one litre of natural stone sealer per square metre of floor.
Step 5: To test the compatibility of the natural stone with the floor sealer, a sample area should first be treated in an inconspicuous place.
Step 6: The sealer must be applied using the so-called cross-coat method. This means that the liquid is applied in one direction and spread in the other.
Step 7: In the final step, the sealed surface must dry for around 24 hours

Sealing natural stone
Seal outside or inside?
Sealing natural stone floors outdoors: Especially on the patio or in the garden, natural stone floors have to withstand some dirt and scratches. For this reason, it is particularly important to clean the patio properly before applying the sealant. Use special natural stone cleaners and brush your patio thoroughly with a soft-bristled broom before you start sealing.
Sealing indoors: Sealing natural stone also makes sense in the bathroom and kitchen. Whether it’s the floor in the bathroom or the worktop in the kitchen. Plan well in advance and bear in mind that you will not be able to use the treated surfaces for at least 24 hours. Very important for owners of underfloor heating: the heating must be switched off before and after sealing so that the correct temperature is not accidentally exceeded.
What are the special features of the different natural stones?
Marble: Probably the most expensive natural stone, it was already extremely popular in ancient times. Marble not only looks very modern and absolutely elegant, it can also be polished and is characterised by its special shine. However, it is also much more sensitive than other natural stones and requires special impregnation to prevent it from scratching or fading too quickly. Marble tiles are therefore less suitable for floors and outdoor areas.
Travertine: This natural stone is very similar to marble and is therefore also known as ‘antique marble’. Travertine is known to store heat particularly well due to its cavities and is therefore ideal as a floor covering in combination with underfloor heating.
Granite: This natural stone is particularly popular as a worktop in the kitchen due to its hardness and durability, but granite tiles are also ideal for outdoor areas. The choice of colours and textures is almost limitless thanks to the high mineral content of granite.
Sandstone: The light-coloured, usually uneven surface of sandstone conveys a warm and cosy atmosphere. In terms of colour, it ranges from light grey to various shades of yellow and brown through to strong red. Sandstone should be treated primarily because it tends to turn green and impregnation or soil sealing can slow down this process. This floor sealer is also an excellent addition to the paving joint mortar water-permeable for concrete sealing and natural stone.
Natural products vs porcelain stoneware
Unlike other types of stone, porcelain stoneware is not a natural product. These are industrial products that can imitate the natural model with astonishing realism. One advantage here is the unlimited choice of customised motifs. Even wood motifs are possible with porcelain stoneware floors. At the same time, porcelain stoneware tiles are not necessarily more expensive than natural tiles. Some types of slate are even cheaper than fine stone. In addition, porcelain stoneware requires less maintenance and cleaning. Regular cleaning with water and a splash of vinegar is sufficient. The only big difference is the feel. Fine stone tiles simply do not come close to the unmistakable feel of natural products.
Maintaining natural stone and removing floor sealant
Natural stone care naturally involves removing dirt from it regularly. While minor dirt should be removed daily, you must clean the surface thoroughly and remove all dirt completely before sealing. PH-neutral cleaners should be used for everyday treatment. Vinegar or acidic cleaning agents attack the surface unnecessarily. Soap or washing-up liquid are also not suitable for cleaning natural stone surfaces, as they create a light film that can reduce the slip resistance of the floor and even lead to discolouration. Pure, lukewarm water is therefore still best for light soiling. A stain protection agent should be used for natural stone that is sensitive to stains. Stone stabilisers are intended for use on brittle natural stone.
The natural stone should be resealed every 2 to 4 years. To do this, however, the old floor sealant must first be completely removed. Specialised solvents reliably remove both impregnations and sealers and ensure that the surface is free of grease and oil.
The floor sealant from Mainbrick
Mainbrick’s porcelain stoneware is ideal for cleaning and maintaining natural stone surfaces. Mainbrick takes care of both the dispatch and delivery of the floor sealant. Our products are shipped free of charge and delivered within a few days. Our cleaners and sealers cover an area of up to 20 square metres per litre. Our customers consistently rate our products with 5 stars. Also take a look at our concrete floor sealers. These also help concrete sealers. You can find other topics such as impregnating stones or re-pointing patios in the guide blog.