Industry News

1. Introduction to Stone Thickness Evolution

In the 1990s, the thickness of stone in the stone processing industry was usually 20mm or greater. However, by the beginning of this century, the thickness of stone began to change, decreasing from 20mm to 18mm, 16mm, and even 10mm. If it is necessary to reduce the weight of buildings, using stone with a thickness of less than 20mm, or even 10mm, as long as the installation strength of the stone meets the usage requirements, it is understandable. Just like ceramic tiles, should their thickness not be more than 10mm? However, for natural stone, due to its natural nature, it is influenced by the natural environment and geological processes during its formation. Different stones have significant differences in their physical and chemical composition and properties. Some stones have a thickness of 20mm or even thinner, and their strength can still meet the requirements of building decoration. However, some stones may not necessarily meet the strength requirements. Therefore, it is necessary to distinguish and differentiate between them. Thin and low strength stones cannot be used for buildings with strength requirements.

2. Differentiation of Stone Types and Thickness Requirements

In practice, there are few nations, industry, and local standards that regulate the appropriate thickness of stone used in buildings. Only appropriate specifications and requirements have been made for the thickness of curtain walls. However, are these thickness requirements scientific and reasonable? The requirements for stone thickness in building decoration should be analyzed in detail, treated differently, and not generalized. It depends on factors such as the variety of stone, the environment in which it is used, the function and purpose of the stone, and the installation method of the stone. Some stones are a few millimeters or even 10mm thick, and the problem is not too big. For example, when installing wall stones with a height of less than 3m and using adhesive installation, thin stones or even 10mm thick stones can be used when the specifications are not large. The thickness of the stone used for non load bearing cabinets that only serve decorative purposes can be thinner. However, when we abuse the thickness of stone without distinguishing specific situations, stone varieties, usage environments, and safety requirements, we are wrong!

3. Practical Issues and Standards in Stone Thickness

Take some kind of construction projects as an example, such as a project that requires a stone thickness of 25mm or 20mm. Due to the difficulty of supplying 25mm thick stone in some countries' markets, some stone companies have negotiated with the general contractor and agreed that the thickness of the stone can be 23mm or 18mm (verbal agreement), without signing a written stone change agreement or contract. The project took several months from start to finish, during which neither the first party nor the general contractor raised any objections to the supplied stone. However, when it came to settling the payment, a problem arose: the first party and the general contractor did not deduct the payment according to the contract based on the thickness of the stone. There are countless cases like this. The problem of stone thickness has not been completely eradicated or changed for a long time, and thin and thinner stones still dominate the stone market, causing endless trouble for stone precision processing enterprises and stone workers. The issue with the 25mm and 18mm thick stone materials mentioned earlier, according to the requirements in Table 2 of Section 6.1.1 of “GB/T19766-2016 Natural Marble Building Panels”, Class A products have a tolerance of ±1.0mm, Class B products have a tolerance of ±1.5mm, and Class C products have a tolerance of ±2.0mm. Therefore, some stone processing companies believe that a stone thickness of -2.0mm is also acceptable. If you think so, you are completely wrong.

4. Economic Pressures and Compliance with Standards

The current situation is that the project party wins the bid at a low price, while the stone processing enterprise inspects the supply with A-level products (superior products), and occasionally some B-level products are barely acceptable. Once the bottom limit of B-level is exceeded, approaching or reaching the quality of C-level products (qualified products), the project party cannot accept it. This is also one reason why the general contractor only verbally agreed that the thickness of the 25mm board should be 23mm and the 20mm board should be 18mm, but did not provide a change notice, as mentioned in the previous case. How can we lower the requirements for B-grade or even C-grade products, as the low price winning bid for the project requires A-grade products? In such a situation, stone suppliers will bear significant losses. Oral contracts are not believed or recognized in China. If the general contractor agrees that the thickness of the stone should be reduced by 2mm, it is acceptable. However, the general contractor still needs to provide a design change notice, which should be signed and approved by the responsible person of the investor (owner). It is not enough for the general contractor to agree alone.

As norms and standards that constrain the behavior of production enterprises and construction units, they should be and strictly enforced, especially mandatory rules and standards, which should not be violated by anyone. Since norms and standards are formulated in this way, they naturally have scientific principles, which have been summarized through long-term use and testing. There has been no clear standard for the appropriate thickness of stone flooring and walls for a long time. However, in the last century, it was customary to use a thickness of 20mm for stone flooring and walls, so this standard has been . But whether this thickness is feasible as a standard for stone walls and floors still needs to be adjusted according to the specific environment, function, and purpose of stone installation and use, and cannot be generalized. In the current practice of the stone industry, stone can be as thin as possible, saved as much as possible, regardless of specific usage scenarios, environments, or functions, and is safe. As long as the stone is thin, cheap, and profitable, it can be done. It is somewhat outrageous that even a dry hanging thickness of 10mm of stone dares to be used on walls, which is really unimaginable?

5. Local Standards and Regulations

We have recently paid attention to a local standard called "Technical Specification for Application of Building Decoration Stone", which includes the thickness of stone and stipulates that except for special circumstances where stone below 10mm can be used, the thickness of stone walls and floors cannot be less than 20mm, stair step cannot be less than 25mm, and the thickness of outdoor floor stone must be ≥ 30mm according to the environment and function. The issue of stone thickness has attracted attention in some places and is being incorporated into the management of construction projects in the form of local building codes. Perhaps the implementation of this regulation can guide the stone industry towards the correct path regarding the appropriate thickness of stone. Stone precision processing enterprises and stone workers will no longer worry about the risks of using thin stone or the deduction of project fees for using thinner stone! The problem of insufficient or even thin stone thickness has been a dilemma for stone processing enterprises for many years, causing a lot of trouble for rough stone processing enterprises and stone workers, and even leading to a decrease in profits for precision stone processing enterprises and stone workers, as stated at the beginning of the article. The issue of insufficient stone thickness has reached the time for this specification!

6. STONELINK's Commitment to Quality and Standards

STONELINK, as a leader in the stone industry, we always adhere to the unremitting pursuit of quality and strict adherence to international standards, and have set an industry benchmark in the standardized implementation of stone thickness. We are well aware that the thickness of stone is not only related to the beauty and durability of products, but also the cornerstone of ensuring building safety and improving overall project quality. STONELINK strictly adheres to and exceeds internationally recognized stone thickness standards in every aspect of stone mining, processing, and quality inspection, including but not limited to ISO (International Organization for Standardization), ASTM (American Society for Testing and Materials), and European EN standards. We use advanced measuring equipment and technological means to precisely control the thickness of each stone, ensuring that the error range is far below the maximum allowed by international standards, thereby providing customers with unparalleled quality assurance.

7. STONELINK's Quality Control and Standard Operating Procedures

We have developed a series of detailed and strict standard operating procedures for the specific implementation of stone thickness specifications based on the type, purpose, and customer needs of the stone. Whether it is natural marble or granite used for high-end architectural decoration, or stone slabs used for outdoor landscape engineering, we can ensure that the thickness of each stone is uniform and consistent, meeting both the requirements of design aesthetics and structural safety. STONELINK has also established a comprehensive quality management system, which tracks and monitors the thickness of stone throughout the process. From raw material storage to finished product delivery, every process undergoes strict quality inspection and recording to ensure that every piece of stone leaving the factory meets or even exceeds customer expectations and international standards.

8. The Importance of Stone Thickness

STONELINK is guided by international standards and based on strict quality control, committed to providing customers with the highest quality and most reliable stone products. We firmly believe that only by constantly pursuing excellence can we stand invincible in the fierce market competition and contribute our own strength to the prosperity and development of the stone industry.