Natural stone in winter

In the garden and on the terrace, natural stone spreads its extraordinary charm. The slabs should therefore also survive frosty temperatures in winter undamaged. When nature awakens, there should be no unpleasant surprises. So what do you need to bear in mind?

Frost and natural stone

Whether a natural stone can withstand ice and frost depends in principle on the water absorption capacity of the natural stone. The more water the material absorbs, the more vulnerable it is to sub-zero temperatures. If a lot of liquid gets into the stone, it expands when it freezes, causing spalling and cracks. So problems only arise at cold temperatures if there is water in the natural stone. However, large pores in natural stone are not automatically bad. Because if the natural stone can release the liquid without any problems, it is still frost-proof. To ensure that the water can be released sufficiently, the choice of substrate is first of all decisive. Thomas Schubert, Managing Director of SCHUBERT STONE, therefore recommends a subfloor made of high-grade chippings or high-grade chippings mortar so that water can seep into the subsoil without accumulating. In addition, it is essential to ensure a slope of 2 % when laying the floor, this ensures good water drainage. On flat surfaces, there is a risk of rainwater or melt water accumulating. When laid professionally, there is no doubt about frost resistance.

The impregnation of natural stone

In order for natural stone to survive a harsh winter, proper care is an important factor. To protect the stone surface, the stone slabs should be impregnated. The impregnation penetrates the stone, but still leaves enough "air to breathe", i.e. water exchange is still possible.

Road salt and natural stone

To keep one's own walkways, stairs and terraces free of ice and slipperiness during frost, road salt often seems the most obvious solution. However, stone expert Thomas Schubert advises against treating natural stone with road salt: "The salts can attack the surface of the natural stone during the freeze-thaw cycles, which can lead to dull spots, stains and discolouration". Caution is especially advised with natural stone types such as limestone, sandstone or travertine. Granite, basalt or quartzite are more resistant and keep snow and ice out due to their stone structure. According to Thomas Schubert, road salt should generally be avoided for natural stone slabs in frosty temperatures and only sand should be used. Large-scale use of road salt is also bad for the soil, for plants and damages the groundwater. Sand-split mixtures fulfil the same purpose as de-icing salt, they ensure slip resistance on frozen and icy ground and thus prevent falling accidents.

Advice for long-lasting pleasure

As you can see - not all natural stone is the same. Each stone has its own colour and properties. Not every natural stone is suitable for a terrace, outdoor staircase or garden design. Therefore, good planning and professional processing is a prerequisite. Therefore, you should take enough time for a competent and comprehensive consultation before laying an outdoor area of natural stone in order to clarify questions regarding frost resistance and the like. Or do you already have a natural stone terrace and still have questions? We will be happy to advise you!

Visit our terrace exhibition in the outdoor area in the stone centre and see for yourself how our natural stones have withstood the weather for years.