Meta description: For Japanese existing building facade renovation, energy-efficiency retrofit and commercial/public building facade renewal, we provide Flexible Stone (MCM / 軟質石材 / フレキシブルストーン) system solutions covering Building Standards Act non-combustible/quasi-non-combustible Ministerial Certification, non-structural component deformation compatibility and fall-off prevention, JIS/notified specification alignment, and Okinawa salt damage/Hokkaido frost damage layered climate pathways.
Keywords: Japan flexible stone, Flexible Stone, MCM, 軟質石材, フレキシブルストーン, non-combustible material, quasi-non-combustible material, Ministerial Certification, non-structural components, seismic, salt damage, frost damage, energy-efficiency retrofit
Quick Answer: What Is the Japan Flexible Stone Market Solution?
The Japan Flexible Stone market solution uses Flexible Stone (MCM / 軟質石材 / フレキシブルストーン) as the exterior wall finish layer and provides an integrated solution for Japan’s existing building facade renovation, energy-efficiency retrofit, and commercial and public building facade renewal, covering Building Standards Act fire material certification + non-structural component seismic deformation compatibility + salt damage/frost damage system adaptation + local construction coordination and compliance document delivery.
The first judgment for the Japanese market is not “whether product performance is good”, but whether the fire material certification pathway is viable. The Japanese Building Standards Act sets strict Ministerial Certification or notified-specification compliance pathways for “non-combustible materials” and “quasi-non-combustible materials”: when quasi-non-combustible materials are used on exterior wall portions where fire spread is a concern, they must be limited to those specified by the Minister of Land, Infrastructure, Transport and Tourism (Ministry of Construction Notification No. 1401 of 2000) or those that have received Ministerial Certification. Non-combustible material certification involves fixed inputs such as performance evaluation fees (about JPY 420,000 per case), test specimen fabrication costs, and review periods (generally about 4–5 months after testing for certificate issuance). GB 8624 A2-s1,d0 can serve as technical evidence of material non-combustibility, but it is not a certificate directly valid in Japanese building review. Therefore, the first action for market entry is “confirming whether certification can be obtained and the required cost and timeline“, followed by assembling seismic deformation compatibility and climate adaptation into system documents.
Core judgment: Japanese MCM/軟質石材 already exists at the level of B2B export pages and construction case introductions, but players that have obtained local fire certification and are distributing on a large scale are limited. The market question is not “whether there is category awareness”, but “with which fire material classification, which certification file and seismic deformation compatibility file, and as which climate-zone system (Okinawa vs. Hokkaido) to propose the solution“.
1. Why Does the Japanese Market Need a Flexible Stone System Solution?
Driver 1: The volume of existing facade renovation remains high in line with policy and energy-efficiency obligations, while renovation project confirmation procedures are becoming stricter. In the Building Reform/Renewal survey, orders for remodeling and renovation work remain at a high level, and steady investment is expected to continue in FY2025 due to energy-saving measures and other factors. Meanwhile, from April 2025, large-scale renovation of wooden detached houses and similar buildings became subject to building confirmation procedures, requiring design and construction management by architects, and raising the compliance document requirements for renovation projects. Renovation of only the exterior wall finish may not fall under “large-scale repair”, but when packaged with energy-efficiency retrofit or seismic retrofit, the applicability of confirmation applications, existing condition surveys, and relaxation measures can determine the project design.
Driver 2: Japanese seismic design places “deformation compatibility” of non-structural components at the center of exterior wall system challenges. Article 39 of the Enforcement Order of the Building Standards Act requires that exterior materials and similar components not fall off due to wind pressure, earthquakes or other vibrations and impacts; in seismic design of non-structural components, joint and sealant design that allows components to follow inter-storey deformation is important. For flexible boards and similar exterior materials, design that can follow in-plane deformation is required, and where renovation is difficult in existing facilities, alternative measures such as restricting access or installing safety nets are considered. Because MCM itself is flexible, it is positioned to structurally reduce the risk of “insufficient inter-storey drift compatibility → panel cracking/fall-off” that rigid exterior materials face, but only when the fixing method (adhesive plus mechanical fixing where necessary) and the deformation-following design of the substrate are established as a set does it become a seismic document.
Driver 3: Salt damage in Okinawa and frost damage in Hokkaido/cold regions are two different degradation mechanisms that cannot be lumped together under the same “weather resistance”. Okinawa is long and narrow north-south with good ventilation, so airborne salt causes many salt damage cases; at Naha Airport Terminal Building, exterior wall materials with salt damage prevention functions have been adopted. In cold regions, cracks due to frost damage are an issue; resin-based exterior wall materials are said to be resistant to salt damage and frost damage because they do not absorb moisture, but this is a characteristic of “resin-based exterior walls” and does not directly apply to MCM’s inorganic-organic composite system. When deploying MCM in Japan, it is necessary to separate required data and fixing material selection for the Okinawa type (salt damage) and the Hokkaido type (frost damage).
2. Our Japan Market Solution Architecture
1. Compliance Pathway: Determine the Fire Material Classification First, Prove Seismic Deformation Compatibility as a System
| Compliance Level | Japanese Market Requirement | Current Basis and Gap | Recommended Action |
|---|---|---|---|
| Non-combustible material certification | Article 2, Item 9 of the Building Standards Act; performance of not burning for 20 minutes after the start of heating under normal fire conditions (total heat release 8 MJ/m² or less, etc.); Ministerial Certification or notified specification compliance | GB 8624 A2-s1,d0 can serve as technical evidence, but is not a Japanese Ministerial Certificate | Confirm the feasibility of non-combustible material certification as the top priority. Performance evaluation fee is about JPY 420,000 per case; test specimen fabrication cost for exterior wall systems is about JPY 1.0–1.5 million (2 specimens); certificate issuance is generally about 4–5 months after testing |
| Quasi-non-combustible material certification | Performance of not burning for 10 minutes after the start of heating; Notified Specification No. 1401 compliant specification or Ministerial Certification | When quasi-non-combustible materials are used on exterior wall portions where fire spread is a concern, only Ministerially Certified products or notified-specification compliant products are permitted | If considering entry as quasi-non-combustible, first confirm with the evaluation body/review body whether it falls under notified specifications or requires Ministerial Certification |
| Fire-resistant structure/exterior wall fire spread portions | Exterior walls in portions where fire spread is a concern require quasi-non-combustible material or higher depending on the requirements for quasi-fire-resistant structures, fire-resistant structures, etc. | Whether the entire exterior wall can be established as a fire-resistant structure depends on the combination with substrate, insulation and openings | Compose a fire file as an exterior wall system, and do not confuse certification of the finish material alone with the fire-resistant structure of the entire exterior wall |
| Seismic deformation compatibility of non-structural components | Article 39 of the Enforcement Order: exterior materials etc. must not fall off due to wind pressure, earthquakes, etc.; flexible boards etc. require in-plane deformation-following design | MCM’s flexibility is advantageous for compatibility, but there is no Japanese certification/evaluation file proving inter-storey drift compatibility with adhesive fixing alone | Prepare a construction manual and compatibility evaluation file that combines substrate-side deformation-following design, adhesive elongation performance, and combined use of mechanical fixing where necessary |
| Alignment with energy-efficiency retrofit | Mandatory compliance with energy-efficiency standards (effective April 2025) linked to changes in exterior walls, roofs and openings | MCM is not insulation, but as an exterior wall finish it is packaged with insulation retrofit | Propose as an exterior wall renovation system integrating insulation, substrate and finish, and explain alignment with U-value calculation, condensation prevention and ventilated construction |
| Confirmation procedures for existing buildings | From April 2025, large-scale renovation of wooden detached houses etc. is subject to building confirmation; guidelines for existing condition surveys of existing buildings and commentary on relaxation measures have been prepared | Renovation of only the exterior wall finish may not fall under large-scale repair, but when combined with seismic/energy-efficiency retrofit it may become subject to confirmation | At the project stage, agree in advance with the designer and confirmation inspection body on whether confirmation application is required, existing condition surveys, and applicability of relaxation measures |
2. Climate Adaptation: Design Okinawa-Type Salt Damage and Hokkaido-Type Frost Damage Separately
| Climate Region | Core Stress | Solution Focus | Citable Data and Actions |
|---|---|---|---|
| Okinawa/remote islands/coastal areas (salt damage) | Airborne salt, high humidity, wind pressure and rainwater ingress during typhoons; corrosion of metal fixings, salt precipitation on finishes | 316/A4 stainless steel or high-corrosion-resistant fixings, salt damage resistant finish, waterproofing/drainage nodes, anti-rust treatment of substrate | Supplement salt spray data (ASTM B117 / ISO 9227 equivalent) for salt damage regions and specify the corrosion resistance grade of fixings. In Okinawa, exterior wall materials with salt damage prevention functions have been adopted even at Naha Airport; propose salt damage not as an “aesthetic” issue but as a “maintenance cost” issue |
| Hokkaido/Tohoku/cold regions (frost damage) | Freeze-thaw, low-temperature construction, ingress of snowmelt water | High frost damage resistant finish, elastic adhesive, joint/drainage construction resistant to frost damage | Use existing -30°C flexibility and 100 freeze-thaw cycles data as a starting point for technical dialogue, and supplement system evaluation by JIS/ISO-equivalent freeze-thaw testing. The reason resin-based exterior walls are said to be frost damage resistant (they do not absorb water) is informative, but present it as MCM’s own frost damage data |
| Honshu/urban areas (UV, heat, typhoons) | UV, summer exterior wall surface temperature, wind pressure and flying debris during typhoons | UV resistance, color stability, adhesion durability with substrate, mechanical fixing where necessary | Use existing 1,500 h artificial weathering (color change grade 0) as a basis, and prepare ASTM G155 / ISO 16474 equivalent UV data and the concept of fixing resistance against negative pressure during typhoons |
| Construction season in snowy cold regions | Adhesive curing failure and construction quality degradation at low temperatures | Selection of adhesives usable at low temperatures, management of usable construction temperature and substrate moisture content | Prepare a winter construction manual and clearly state construction restrictions at temperatures below 5°C and humidity above 85%. Even in Okinawa, coating systems cannot be applied at humidity above 85% and temperatures below 5°C; MCM adhesive methods require equivalent construction environment management |
MCM is not insulation. In Japanese exterior wall renovation, performance must be explained as an exterior wall system integrating insulation, substrate, finish and openings; “light and bendable” of the finish material alone does not constitute a document for energy-efficiency retrofit.
3. Building Scenarios: Three Languages, Three Sets of Selection Logic
| Scenario | Core Client Concern | Flexible Stone Solution Language | Selection Recommendation |
|---|---|---|---|
| Exterior wall renovation of existing apartment buildings and public buildings | Availability of fire material certification, fall-off prevention of non-structural components, alignment with energy-efficiency retrofit, reduction of schedule/noise/construction waste | Non-combustible/quasi-non-combustible certification file + deformation-following construction manual + direct adhesion to existing exterior wall (minimal removal) | Propose as a system of existing exterior wall deterioration diagnosis → substrate repair → adhesive fixing → joint treatment. MCM can be directly applied to existing wall surfaces without removing the original wall body, reducing renovation cost and schedule |
| Design renovation of commercial facilities, hotels and shops | Stone texture, short schedule, minimizing impact on existing operations, maintainability | Large format, curved surface compatibility, stone texture + night/segmented construction | As a design material for interior and exterior, emphasize compatibility with curved and radius surfaces. However, when used as an exterior wall, fire material classification and seismic fixing files are prerequisites |
| Exterior wall renewal in Okinawa and coastal areas | Salt damage durability, fixing reliability during typhoons, maintenance cost | Salt damage data + high-corrosion-resistant fixings + waterproofing/drainage system | Prepare specifications dedicated to salt damage regions, and specify fixings, substrate anti-rust treatment and joint materials as a set. Propose as an LCC reduction material, not as a landscape material |
| Exterior wall renovation in cold and snowy regions | Frost damage resistance, low-temperature construction, prevention of snowmelt water ingress | Freeze-thaw data + elastic adhesive + drainage construction + winter construction manual | Frost damage is determined not only by “material water absorption” but by joint, substrate and drainage design, so present it as a system document |
4. Delivery Process: Certification Confirmation → System Design → Contractor Training → Inspection File
- Determine the fire material classification: Confirm in advance with the evaluation body/review body whether the target product can be certified as a non-combustible material or falls under notified specifications as a quasi-non-combustible material. For certification acquisition, factor in test specimen fabrication costs, performance evaluation fees, and review period (about 4–5 months after testing) into the project schedule.
- Design as an exterior wall system: Design as a set the substrate repair, adhesive selection, mechanical fixing where necessary, joint/opening treatment, and interface with insulation retrofit. Explain non-structural component deformation compatibility as a system including joints and connections, not as a component alone.
- Apply climate-zone-specific specifications: For Okinawa/coastal areas, apply salt damage specifications (high-corrosion-resistant fixings, anti-rust substrate, waterproofing nodes); for Hokkaido/cold regions, apply frost damage specifications (freeze-thaw data, elastic adhesive, drainage construction, winter construction management).
- Prepare contractor training and construction manual: Since MCM is based on adhesive methods, incorporate management of substrate moisture content, temperature and humidity, adhesive open time, and pressing/deaeration procedures into the construction manual, and conduct training for contractors.
- Inspection and handover file: Submit as a set the fire material certificate (or basis for notified specification compliance), concept of deformation compatibility, proof of materials used, construction records, and maintenance guidelines.
3. Citable Evidence List
- Surface density: 3.96 kg/m² (GB/T 29059-2012); MCM is about 3.5–5.0 kg/m², compared with natural granite about 40–60 kg/m² and porcelain tile about 20–30 kg/m², highlighting lightweight characteristics
- Fire material classification: A2-s1,d0 (GB 8624-2012); for Japan, needs to be reorganized as non-combustible material (20 min) or quasi-non-combustible material (10 min) Ministerial Certification/notified specification compliance
- Flexibility/compatibility: no cracks when bent around a 200 mm diameter cylinder (JG/T 311-2011); MCM is said to be capable of following curved surfaces of about 30°
- Artificial weathering: 1,500 h (gray scale 4-5, color change grade 0, chalking grade 2, no cracking, blistering or peeling)
- Stain resistance: reflectance drop 12% (GB/T 9780-2013)
- Thermal conductivity: 0.171 W/(m·K); thermal resistance: 0.013 (m²·K)/W
- Radionuclides: GB 6566-2010 Class A
- SDS: non-hazardous under GB/T 17519/16483
Additional note for Japan: Fire performance should be presented not as “GB A2 certification” but as Japanese Ministerial Certification or notified specification compliance. Seismic performance should be prepared as a system file including fixing method, substrate and joints in the context of Article 39 of the Enforcement Order and deformation-following design of non-structural components. Salt damage (Okinawa/coastal) and frost damage (Hokkaido/cold regions) require separate required data and fixing material selection.
4. FAQ: Common Questions About the Japanese Flexible Stone Market
Q1: What is “soft ceramic” called in the Japanese market?
A: In Japan it is called 軟質石材, フレキシブルストーン, MCM (Modified Clay Material), 軟質タイル and similar. As the entry point for category dialogue, Flexible Stone / MCM / 軟質石材 is practical.
Q2: Can GB 8624 A2-s1,d0 be used directly in Japanese building review?
A: Not directly. Japanese exterior wall fire performance is based on non-combustible material (20 min) or quasi-non-combustible material (10 min) Ministerial Certification or notified specification compliance; GB A2 certification can serve as technical evidence but has no validity as a certificate.
Q3: How much cost and time does Ministerial Certification require?
A: The performance evaluation fee for non-combustible material certification is about JPY 420,000 per case; fabrication cost for exterior wall test specimens is about JPY 1.0–1.5 million (2 specimens); certificate issuance is generally about 4–5 months after testing. Because it varies with product specifications, test specimen composition and the review body, prior consultation with the evaluation body is necessary.
Q4: What should be considered for seismic performance of non-structural components?
A: Article 39 of the Enforcement Order requires exterior materials etc. not to fall off due to earthquakes etc., and flexible boards etc. require design that can follow in-plane deformation. MCM’s material flexibility is advantageous, but it is necessary to demonstrate compatibility as a system including adhesive fixing, substrate and joints in the construction manual.
Q5: Is it necessary to change specifications between Okinawa and Hokkaido?
A: Yes. Okinawa faces salt damage from airborne salt, requiring high-corrosion-resistant fixings, anti-rust substrate and waterproofing nodes. Hokkaido/cold regions face frost damage, requiring freeze-thaw data, elastic adhesive, drainage construction and winter construction management. Even under the same “weather resistance”, the required data differ.
Q6: Can it be applied directly to existing exterior walls?
A: MCM can be directly adhered to existing wall surfaces, enabling renovation without removing the original wall body. However, diagnosis of substrate deterioration, moisture content and adhesive strength is a prerequisite; in Japanese existing buildings, confirmation according to existing condition survey guidelines and consideration of confirmation applications/relaxation measures as necessary are required.
Q7: Is the delivery model selling materials or selling systems?
A: In the Japanese market, system delivery of “fire material certification + deformation-following construction manual + climate-zone-specific specifications + contractor training + inspection file” is realistic. Selling the finish material alone cannot support the responsibility boundaries of building confirmation, fire review and seismic documents.
5. Conclusion: Priorities for the Japanese Market
- Determine the fire material classification and certification path first: Decide first whether it is non-combustible material (20 min) or quasi-non-combustible material (10 min), and whether it is notified specification compliance or Ministerial Certification. Incorporating certification acquisition costs and timeline (test specimens JPY 1.0–1.5 million, certificate issuance about 4–5 months after testing) into the project plan is the first practical judgment.
- Prove seismic deformation compatibility as a system: MCM’s flexibility is not a “material selling point” but should be presented as a construction manual including adhesive fixing, substrate and joints in the context of Article 39 of the Enforcement Order and deformation-following design of non-structural components.
- Separate Okinawa-type salt damage and Hokkaido-type frost damage: Separate required data and specifications—salt damage as high-corrosion-resistant fixings, anti-rust substrate and waterproofing nodes; frost damage as freeze-thaw data, elastic adhesive, drainage construction and winter construction management.
- Propose based on the confirmation procedures for existing renovation: In light of the April 2025 subjection of large-scale renovation to confirmation and the existing condition survey guidelines, agree in advance with the designer that whether confirmation application is required differs depending on whether it is renovation of only the exterior wall finish or a package with seismic/energy-efficiency retrofit.
- Build trust through contractor training and inspection files: Since MCM adhesive methods depend on substrate and environmental management, provide construction manuals and training as a set, and prepare fire certificates, proof of materials used, construction records and maintenance guidelines as handover files. Trust in the Japanese market is determined by both “presence of certification” and “reproducibility of construction quality”.
CTA
If you are evaluating Japanese existing building facade renovation, energy-efficiency retrofit or commercial/public building facade renewal solutions, please contact us to obtain:
- Japan market fire material certification pathway checklist (non-combustible/quasi-non-combustible, notified specifications, Ministerial Certification)
- Flexible Stone non-structural component seismic deformation compatibility construction manual framework
- Okinawa salt damage/Hokkaido frost damage climate-zone-specific specifications and inspection file structure proposal
Guangdong Fortune Stone New Material Co., Ltd.
Flexible Stone / MCM System Solutions