Frequently asked questions

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What must I know when choosing a natural stone?

There are thousands of types of natural stone worldwide. Despite being sorted into classes, each stone is unique and suitable for certain applications. The granite mined by Kusser is suitable for almost all applications we know of. Should you have any further requirements and wishes, we will gladly consult with you.

Where can I get help for construction with natural stone?

Independent information and the current status of construction technology is compiled in the structural information of the Naturwerksteinverbandes (DNV, Natural Stone Association). https://www.natursteinverband.de/The Kusser team is very familiar with these regulations and will gladly consult with you with regards to your particular application case.

How thick must natural stone be in floor coverings?

This question does not have a single answer. The thickness of the floor coverings depends on the chosen material, the format of the floor coverings, the construction, and the expected load.

For Kusser granites, the following rules of thumb serve as orientation:

Floor covering for outdoor private patios: 3 - 4cm
Interior floor coverings: 2 – 3 cm
Garage driveways for cars: 6 – 10 cm
Public pedestrian zones with occasional heavy vehicle traffic: 12 cm
Street surfaces with heavy vehicle traffic: 16 cm
Street surfaces with regular heavy vehicle traffic (e.g. bus lanes): 18 cm

These thicknesses are only an orientation. Discuss your particular application case with us. We will be happy to assist you.

For which applications is natural stone particularly suitable?

Natural stones are aesthetically pleasing and extremely durable. They are therefore suitable wherever these characteristics are required.

Typical application areas are:

  • Natural stones in walls
  • Window and doorframes
  • Indoor and outdoor stairways
  • Indoor and outdoor floor coverings
  • Wall and facade coverings

As well as the typical application fields, natural stone is perfectly suited for use in fountain and bridge construction due to its durability and aesthetics. 

For which applications is natural stone particularly suitable?

As the name suggests, natural stone is a natural product. This means that no two stones look the same. Even the stones from the same quarry are never identical. Color differences, inclusions, veins, and differences in the grain are therefore not flaws or blemishes, but give the stone its particular charm and appeal. Applications with stringent coloring, and extreme requirements regarding uniformity in every detail, cannot be realized using natural stone. Man-made materials are far more suited to these applications.

What elements must be observed when planning the use of natural stone?

As a raw material, natural stone is less expensive compared to other materials. The durability of the material means that processing is complex and expensive and this is the main cost factor of the end product. Natural stone must be used in a manner that does justice to the material. This means making a design from a solid block, with intricate transitions and details. Natural stone should essentially have a bespoke design, with formats individually tailored to the use to match the preplanned joints. Especially the connection details must be planned and determined.

What are boundary samples and why must they be implemented?

Natural materials come in all different shapes and sizes. No stone is the same as another. Therefore, it is not recommended to choose a stone for a large area based upon a single sample stone. The inspection of sufficiently sized reference surfaces is an ideal solution. Alternatively, boundary samples can be determined. These define the scope of the permitted differences in the stones. These boundary samples can also determine color differences, veins, and inclusions. The smaller you set the boundaries, the higher the sorting effort will be, and the more expensive the end product will be. Ideally, natural stone is chosen that can be used without much additional sorting effort, despite the naturally occurring variance. This gives the best results in our experience.

How and with what products do I clean natural stone?

In most cases, water or a normal soap solution is sufficient. Steam cleaners can readily be used on natural stone outdoors, as long as loose joints or sensitive substructures are properly protected. Due to the durability of the material, stubborn dirt can also be cleaned using aggressive special cleaners. Using these cleaners requires experience and expertise. We will gladly consult with you about your application case.

Which standard formats or off-the-shelf products do Kusser have in stock?

Here at Kusser, we believe that the formats of a high-quality material should be tailored individually to your requirements. This is also a sign of quality. Therefore, we do not have any standardized products, but create bespoke products for your applications. High production capacity in Germany, and raw material resources in our own quarries help keep delivery times down, and ensure we serve our customers on time.

What are the technical specifications of Kusser granite?

Our granite has a density of between 2.6 – 2.8 t/m³. The compressive strength is approximately 180 N/mm², and the flexural strength approximately 14 N/mm². The heat expansion coefficient of Kusser granites is approximately 7 x 10 -6 1/K. The Poisson ratio is approximately 0.15.

Which services does Kusser offer for natural stone work?

Kusser offers independent planning for natural stone work, completely separate from the subsequent production and installation of the products. We manufacture our natural stone products in our own factories in Bavaria. We also deliver using our own vehicle fleet, or with the support of reliable partners. As opposed to fountain and bridge construction, which are services we offer worldwide with our own staff, we mainly restrict our natural stone installation work to Bavaria. Ultimately, however, you are the one who decides which services you commission from us.

What is a declaration of performance and what are CE labels, and must they be observed?

According to EU construction product regulations, only construction products with a declaration of performance and CE labels are allowed to be put into circulation. Therefore, you as the contractor and planner should request this information from the manufacturer in advance. The declaration of performance provides information on the guaranteed characteristics of the construction product. The CE label on the product or the delivery receipt, enables the identification of the delivered product. To be on the safe side, we recommend that contractors and architects also request the test certificates from the factory production checks. This way you can ensure that the chosen materials have the required characteristics.

We will gladly provide you with the declaration of performance and the test certificates of our products. Simply contact us and we will send you the relevant documents.

How does Kusser permanently ensure the required product quality?

We also have regular in-house production checks that go beyond the mandatory intervals. We also have our own construction material test laboratory to quickly check the stone and product quality.