FortuneReshaping Facades The Global Renovation Wave and the Flexible Stone Alternative-chapter3
Part III Flexible Stone: Technical Foundation and Compliance Framework for Global Material Substitution
Opening: From "Impossible Triangle" to "Possible"
The analysis in the first two parts points to the same conclusion: old building scenarios impose three simultaneous requirements on facade materials – lightweight, durable, compliant. Traditional materials each expose their shortcomings in the face of this "impossible triangle": paint is severely insufficient in durability; tiles and stone have problems in lightweight and some compliance dimensions; lightweight materials such as aluminum composite panels have major risks in fire safety compliance.
The fundamental reason why flexible stone can establish substitution potential in old building scenarios is not its aesthetic effect or material unit price, but its technical foundation that exactly addresses all three conditions simultaneously.
This part systematically elaborates the technical strengths of flexible stone from four dimensions: material science, international standards, economic models and environmental value.
Chapter 8 What is Flexible Stone: Material Science and Process Principles
8.1 Definition and Technical Name
Flexible stone, the more standard name is modified inorganic powder composite building facing sheet. According to the standard Modified Clay Material (MCM) Composite Building Facing Sheets (Flexible Stone) issued and implemented in 2025, flexible stone is a kind of flexible building decoration material made of Modified Clay Material (MCM) as the main raw material, formed by a special temperature-controlled molding system, baked and radiation crosslinked. The standard is under the jurisdiction of the China Commercial Enterprise Management Association, and stipulates product classification, appearance quality, dimensional deviation, and core technical requirements such as water absorption and frost resistance.
The common name "flexible stone" is easily misleading. It is not actually porcelain, nor is it a ceramic tile. It is a flexible building decoration material mainly made of inorganic mineral powder and manufactured through low-temperature molding technology. Because it had the appearance effect of ceramic tiles at the beginning of its birth, it was commonly called "flexible stone". With the development of technology, flexible stone can already imitate the effects of various materials such as stone, leather grain and wood.
Technical research on flexible stone can be traced back to 2003, when related projects were launched in Texas, USA, originally intended to replace asphalt. In 2008, a Chinese enterprise focusing on this field was formally established, applying MCM materials to the field of building decoration. In 2012, MCM flexible stone won the silver award at the 7th International Invention Exposition. In 2014, flexible stone was included in the National Key Supported High-Tech Fields. Entering the 2020s, the flexible stone market continues to develop. In 2023, the national market size of flexible stone materials was about 8.5 billion yuan, and in 2025 the product obtained China Green Product Certification.
8.2 Raw Materials and Production Process
The core raw materials of flexible stone are urban construction waste soil, cement scraps, ceramic residues and stone powder and other inorganic substances, with water-based polymer added, formed through composite modification and more than 30 production processes. These raw materials are widely available, low-cost, and largely derived from the recycling of construction waste, endowing flexible stone with inherent circular economy attributes.
The core links of the production process include: raw material crushing and composite modification, molding under photochemical isomerization and controlled curve temperature, baking and radiation crosslinking. The composite modified soil has plasticity and can be made into various shapes such as sheets, blocks, coils and profiles. The entire production process is completed under low temperature conditions, with energy consumption of about 0.2 kWh per square meter, far lower than the high-temperature firing process of traditional tiles and stone.
The surface texture of flexible stone is based on natural material texture or elements of historical crafts, produced by photosensitive mold cloning technology, with natural texture presentation. The color of the material is mainly determined by the origin of the soil used. Original ecological soil has rich colors, mainly in composite gray series, with up to 256 color combinations.
8.3 Core Physical Properties
The physical performance parameters of flexible stone directly respond to the requirements of old building scenarios for materials.
Extremely light weight. Flexible stone is usually 2 to 10 mm thick, with a self-weight (including auxiliary materials) of no more than 6 kg per square meter, bearing only 3 to 8 kg/m², one-fifth to one-tenth of traditional tiles. This feature gives it natural advantages in old building scenarios: it does not increase the additional load of the building structure, does not exacerbate the risk of falling objects from heights, and significantly reduces transportation energy consumption.
Excellent flexibility. The tensile strength of flexible stone can reach 4.8 MPa, and the elongation at break can reach 83.2%. It can be bent around a 200 mm diameter rod for one full circle without cracks or breakage. This flexibility enables it to adapt to micro-deformation and temperature deformation of old walls, and has incomparable adaptability compared with traditional rigid materials when constructed on old building bases.
Breathable and waterproof. The water absorption of flexible stone is about 2%, and the water vapor transmission rate is 0.95 g/(m²·h), combining water repellency and air permeability. This means that flexible stone can effectively prevent external rainwater from penetrating, while allowing water vapor inside the wall to be discharged outward, avoiding blistering and peeling of the facing layer caused by water vapor accumulation. This feature is particularly critical in old building scenarios – old walls often have high moisture content, and impermeable facing materials will exacerbate base layer degradation.
Strong weather resistance. After testing, flexible stone shows no cracks or chalking after 2000 hours of artificial climate aging and artificial radiation exposure; after 100 repeated freeze-thaw cycles in the range of -30°C to above 10°C, there are no cracks, peeling, discoloration or other phenomena. The national standard requires 2000 hours of artificial aging, which is more than 3 times the durability standard of stone-like paint. The weather resistance and anti-aging performance of flexible stone far exceed conventional paint, giving it a significant life-cycle advantage in old building scenarios.
Fire performance. The fire rating of flexible stone can reach Class A2 (GB 8624-2012), and some products can reach Class A1. Its raw materials are mainly inorganic mineral powder, which inherently has excellent flame retardant properties. By adding Portland cement, ground calcium carbonate, quartz sand, emulsion and flame retardants to the formula, flexible stone with Class A2 combustion performance can be produced, while maintaining good waterproofness, flexibility and flame retardancy.
8.4 Differences from Flexible Stone Veneer
In the international market, flexible stone is often classified as "flexible stone veneer" or "flexible tile", but there are essential differences between the two.
Flexible tiles and flexible stone veneer are mainly made of natural stone sheets or ceramic sheets, achieving flexibility through backing mesh or fiber layers, with the core still being natural stone or ceramic materials. Flexible stone, on the other hand, is made of inorganic mineral powder through composite modification and low-temperature molding processes, and its material properties are closer to "modified soil" rather than "stone" or "ceramic".
This difference determines that flexible stone has lower raw material costs, higher design flexibility and better recyclability. Flexible stone can be recycled for reproduction, or reduced to soil state through physical and chemical treatment. At the same time, the color and texture of flexible stone can be achieved through formula adjustment, not limited by natural stone sources.
Chapter 9 International Standards and Certification System
9.1 Why Certification is Key to Going Global
For flexible stone to enter the global old building renovation market, certification is an unavoidable threshold.
CE certification in Europe, ASTM testing in North America, the globally applicable ISO system – these certifications are not only passes for market access, but also the basis for proving product performance and safety to designers, contractors and owners. In old building projects, material selection is strictly constrained by regulations, and products without compliance certification can hardly enter the bidding catalog.
9.2 Fire Certification: CE and EN 13501-1
EN 13501-1 is the core standard for fire classification of construction products in the EU, dividing the combustion performance of construction products into seven grades from A1 to F, with A1 being the highest grade and F the lowest. The standard requires facade systems to be tested as complete components, i.e. insulation layers, cladding, cavity barriers and fixings need to be evaluated together, rather than tested separately.
Flexible stone has passed CE certification and China Class A fire certification. The fire rating reaches Class A or A2 standard, and some products reach Class A1. This means that flexible stone can meet the strict fire performance requirements for high-rise building facade materials in Europe. After the Grenfell Tower fire in the UK, facade materials for buildings over 18 meters are strictly restricted, and the EN 13501-1 standard becomes a mandatory requirement.
9.3 US Standards: ASTM E84 and NFPA 285
In the US market, ASTM E84 is the standard test for surface burning characteristics of building materials, requiring a flame spread index of no more than 25 (Class A) and a smoke development index of no more than 450. For buildings over 12.2 meters (40 feet), large-scale fire testing by NFPA 285 is also required.
Flexible stone products have passed the ASTM test standard and meet Class A fire requirements. This means that flexible stone can be used in high-rise buildings in the United States. At the same time, flexible stone has obtained US patents, clearing intellectual property obstacles for entering the US market.
9.4 Other International Certifications
The international certification system that flexible stone has obtained includes: ISO 9001 Quality Management System certification, ISO 14001 Environmental Management System certification, CE safety certification, SGS test report, GREENGUARD certification, as well as regional certifications such as KC (South Korea) and MIC (Malaysia).
GREENGUARD certification is a third-party certification standard for indoor chemical emissions of products, covering VOC, formaldehyde and other harmful substance emission tests. Flexible stone has passed GREENGUARD certification, meaning its VOC emissions meet strict standards and can be safely used in sensitive environments such as schools and hospitals.
In terms of standard globalization, Chinese flexible stone enterprises started the internationalization process of MCM standards after 2014, successively leading the compilation of MCM industry standards in China, Malaysia, India, Indonesia and South Korea, and promoting the formulation of MCM industry standards in the US and EU. This means that flexible stone is moving from a "Chinese product" to a "global category supported by international standards".
Chapter 10 Life-Cycle Cost: Economics from a Global Perspective
10.1 The Truth About Initial Costs
The material unit price of flexible stone is higher than ordinary paint, but lower than high-end stone and tiles. This is a fact that is repeatedly mentioned, but also the most easily misread fact.
In old building projects, initial cost is never a simple comparison of material unit prices, but a comprehensive calculation including removal fees, waste disposal fees, base treatment fees, scaffolding fees, labor costs and schedule losses.
Traditional paint renovation schemes require first treating the old base layer: removing hollow and peeling old coatings, repairing cracks and depressions, applying interface agents, and then painting. This process generates construction waste that needs to be hauled away, scaffolding costs money, and disruption to residents’ lives and building operations during construction needs to be measured.
The advantage of the flexible stone scheme lies in its no-demolition feature: only the parts with safety hazards need to be knocked off and leveled, and then directly pasted on the old wall, "no need to spend a lot of effort to knock off the original paint, tiles or mosaics and other products". This means that removal costs, waste disposal costs and construction time are significantly reduced. Under the premise of achieving similar stone-like texture, inkjet travertine-type flexible stone costs about 100 yuan per square meter including labor costs, far lower than the cost of similar texture paint of 200 to 300 yuan per square meter.
10.2 Life-Cycle Cost Comparison Model
To truly understand the economics of flexible stone, one needs to extend the perspective to a cycle of 20 years or even longer.
The 20-year cumulative cost of a paint renovation project includes: initial painting of about 45 yuan/m², local maintenance at the 5-year node of about 12 yuan/m², full repainting at the 8-year node of about 32 yuan/m², maintenance again at the 13-year node of about 12 yuan/m², and repainting again at the 16-year node of about 32 yuan/m². The total is about 133 yuan/m². If considering the additional removal and leveling costs due to deteriorating base conditions during the second and third repaints, this figure will be even higher.
The initial installation cost of a flexible stone system is about 100 to 150 yuan/m² (including materials, adhesive and labor), but there is almost no maintenance and renovation cost within a 20-year cycle. The service life of flexible stone can reach more than 20 years, with one-time construction and long-term stability, without frequent cleaning, renovation and repair.
Overall, the comprehensive cost of flexible stone is 30% to 50% of marble, comparable to stone-like paint, but with a much longer service life. Over a full cycle of 5 years or more, the comprehensive construction cost of flexible stone can be saved by more than 50%. The crossover point of life-cycle costs between the two usually occurs between 12 and 15 years.
10.3 Overlooked Cost Items
In the comparison of life-cycle costs, there are three often-overlooked cost items worthy of separate discussion.
Construction disruption cost. Every repaint requires scaffolding, closing facades, generating noise and dust. For residential communities still in use or commercial buildings in operation, the cost of this disruption is not only residents’ complaints, but also lost business revenue. The thin-bed tiling process of flexible stone is fast and requires fewer procedures, and the disruption to building operations is much lower than repeated painting schemes.
Safety risk cost. If the old wall has hollow tiles or loose base layers, paint solutions cannot eliminate the fall risk. Once a falling accident occurs, liability and compensation costs will become an additional burden on the project party. The lightweight characteristics and flexible pasting process of flexible stone fundamentally reduce the risk of falling objects from heights.
Carbon cost. In the European carbon trading system, carbon emissions from building materials are being included in project cost accounting. The EU building decarbonization target requires that the renovation process itself be low-carbon, and the traditional model of "demolition – disposal – re-construction" is increasingly difficult to pass review under this standard. The production energy consumption of flexible stone is only about 0.2 kWh per square meter, waste can be recycled and regenerated, and radioactivity and heavy metal content meet environmental standards. Its zero-carbon facing materials can reduce carbon by up to 95.4% compared with ceramics. This makes the carbon cost advantage of flexible stone particularly prominent in the European market.
10.4 Carbon Footprint and Circular Economy Value
The environmental value of flexible stone is not only reflected in the use stage, but also throughout the entire life cycle.
At the raw material end, flexible stone is based on inorganic solid waste such as urban construction waste soil, cement scraps, ceramic residues and stone powder, with a high solid waste utilization rate. Ecological flexible stone can achieve a solid waste utilization rate of up to 70%, with a life-cycle carbon emission of 0.66 kg CO₂e per kilogram of product.
At the production end, flexible stone adopts a low-temperature molding process, without the high-temperature firing link of traditional building materials, and the comprehensive production energy consumption is only 25.6% of the international standard. Energy consumption per square meter is about 0.2 kWh, far lower than tiles and stone.
At the transportation end, flexible stone weighs only 4 kg per square meter, reducing energy consumption during transportation by up to 94% compared with stone. For the export market, this means lower logistics costs and a smaller carbon footprint.
At the recycling end, flexible stone can be recycled for reproduction, or reduced to soil state through physical and chemical treatment, returning to nature. This "from soil, back to soil" circular model conforms to the global construction industry’s pursuit of circular economy.
Summary of Part III: Technical Strengths and Substitution Logic of Flexible Stone
The technical foundation of flexible stone consists of four dimensions: lightweight and flexible material science, compliance guarantee of international certification, economic advantage of life-cycle cost, and environmental value of circular economy.
These four dimensions together respond to the three simultaneous requirements of "lightweight, durable, compliant" for facade materials in old building scenarios. Flexible stone is not "better" in one single dimension, but satisfies all three dimensions simultaneously – something that paint, tiles and stone cannot each do on their own.
But technical strengths do not equal market success. For flexible stone to truly establish its substitution position in the global old building renovation market, it still needs to solve a series of problems such as construction standardization, channel construction, brand recognition and regional market adaptation. Part IV will start from six major application scenarios around the world, demonstrating the practical application and verification results of flexible stone in different old building scenarios.