Chapter 8

Standards, Certification, and On-Site Acceptance: From Product Compliance to System Compliance

Compiled by Guangdong Fortune Stone New Material Co., Ltd.

Key Points

• Flexible stone is a “mature category with standards.” The standard system consists of four layers: product standards, system standards, fire protection standards, and environmental protection standards. Doing things according to standards is only passing; exceeding standards is excellence.
• On-site acceptance implements the “four-step verification method”: verify the report, verify the product, verify the batch, and verify re-inspection.
• System compliance locks in five keys: bonding agent, substrate, fire protection, construction, and acceptance.

8.1 Panorama of the Flexible Stone Standard System

8.1.1 Product Standards

The core product standards for flexible stone are JG/T 311 Flexible Facing Brick and JC/T 2219 Modified Inorganic Powder Composite Building Facing Sheet[1-2]. JG/T 311 specifies the terms and definitions, classification and marking, technical requirements, test methods, inspection rules, marking, packaging, transportation, and storage of flexible stone products. JC/T 2219 further refines the product performance requirements for flexible stone materials.

It should be clarified that standards are the “bottom line,” not the “ceiling.” Doing things according to standards is only passing; exceeding standards is excellence. When the client asks “do you have test reports,” you should be able to produce a “full set of test reports”—product testing, system testing, combustion performance, and environmental testing, none can be omitted. Standard certification is not “paying money for a certificate,” but “speaking with data.” Behind every report is the product’s “credit endorsement.”

8.1.2 System Standards

System standards address the performance of the system composed of “flexible stone + bonding layer + insulation layer + substrate,” rather than the performance of a single piece of flexible stone. System standards cover a broader scope because they involve multi-party compatibility—material suppliers, bonding agent suppliers, construction parties, design institutes, and supervisors.

Table 8-1 Flexible Stone System Standards

[3-5]

Case: A facade retrofit project used flexible stone to renovate exterior walls. The material test reports showed all indicators qualified, but local hollowing appeared after construction. Investigation found that the construction unit only checked material standards and did not perform interface treatment on the original exterior wall substrate according to JGJ 144 system standards. After supplementary substrate reinforcement and interface treatment according to system standards, the second acceptance passed.

Case insight: Product qualification does not equal system qualification. Flexible stone single-piece performance meeting standards is only the first step; system standards are the complete basis for ensuring final project quality. Procurement and construction links must simultaneously refer to product standards and system standards.

8.1.3 Fire Protection Standards

Fire protection standards are a mandatory field, and fire protection compliance cannot be omitted. The combustion performance of the flexible stone facing layer needs to be tested according to GB 8624 Classification for Burning Behavior of Building Materials and Products, divided into A/A2/B1/B2/B3 levels[6]. Building fire protection design needs to be implemented according to GB 50016 Code for Fire Protection Design of Buildings and GB 55037 General Code for Building Fire Protection[7-8].

8.1.4 Environmental Protection Standards

Environmental protection standards convey environmental information through certification and labeling. Flexible stone needs to meet the requirements of GB 18582 Limit of Harmful Substances in Wall Coatings for Buildings and GB 6566 Limits of Radionuclides in Building Materials[9-10]. Green building materials certification is an important threshold for flexible stone to enter the government procurement market.

8.2 Full List of Test Reports

A complete flexible stone product test report system should include the following content:

Table 8-2 Full List of Flexible Stone Test Reports

A full set of test reports is a “signal combination,” conveying a stronger quality signal than a single report. For procurement parties, a full set of test reports significantly reduces their own verification costs; for material suppliers, certification certificates eliminate the burden of proving quality item by item to each customer.

Case: In a project, the client received only one type inspection report upon entry and began supply. After the supervisor checked against the full list, it was found that combustion performance and environmental protection indicator reports were missing, and the material supplier was required to complete them before batch entry. The material supplier subsequently supplemented the full set of reports, avoiding major risks in the subsequent acceptance stage.

Case insight: On-site acceptance must verify the full set of reports, not just one. Combustion performance and environmental protection indicators relate to safety and user health; missing any one may cause acceptance blockage or even rework.

It should be specially noted that some key indicators in the test reports are technically supported by continuous independent research and development. A systematic technical layout has been formed around emulsion formulas, supporting the compliance and improvement of various flexible stone performance indicators from the materials science level: the large-particle-size high-permeability flexible stone emulsion technology solves the balance between breathability and flexibility, providing technical support for breathability indicators; the non-migratory emulsion technology based on reactive emulsifiers solves the interface stability problem, providing a materials science foundation for the stability of tensile bonding strength indicators; the high-flexibility emulsion technology solves the wide-temperature-range durability problem, providing technical assurance for freeze-thaw resistance and artificial weathering resistance indicators; the inorganic silicone resin modified acrylic emulsion technology for flexible stone topcoats solves the surface weather resistance and stain resistance problem, providing technical support for stain resistance indicators. The engineering verification data of these independent R&D technologies constitute an important technical background for test report verification.

8.3 The “Four-Step Verification Method” of On-Site Acceptance

8.3.1 Step One: Verify the Report

Check whether product test reports are complete and valid: whether the report is within the validity period (type inspection reports are usually valid for 2–3 years); whether the test items cover key indicators (surface density, bonding strength, combustion performance, etc.); whether the testing institution has CMA qualification; whether the report number is verifiable.

Table 8-3 Test Report Verification Checklist

8.3.2 Step Two: Verify the Product

Check product appearance and labeling: whether product color and texture are consistent with the sample; whether product thickness and dimensions meet standards; whether product packaging labels are clear (brand, model, batch number).

Table 8-4 Product Verification Checklist

8.3.3 Step Three: Verify the Batch

Check batch consistency: whether the same facade uses the same batch; whether batch numbers correspond to test reports; whether there is color difference risk between different batches.

Table 8-5 Batch Verification Checklist

8.3.4 Step Four: Verify Re-Inspection

Conduct re-inspection when necessary: key indicators (bonding strength, combustion performance) can be sent to a third party for re-inspection; compare re-inspection results with factory reports; batches that fail re-inspection must be resolutely returned.

Table 8-6 Re-Inspection Verification Checklist

Case: During on-site acceptance of a facade retrofit project, the supervisor found that the batch numbers of incoming products did not correspond to the test report batches, and two different batches of the same flexible stone were mixed on the same facade. Testing showed that the color difference ΔE between the two batches reached 4.5, exceeding the qualified standard. The material supplier adjusted the supply plan, and the same facade was entirely switched to the same batch, resolving the color difference problem.

Case insight: The four-step verification is interlinked. Verifying the report solves the “report authenticity” problem, verifying the product solves the “goods correctness” problem, verifying the batch solves the “goods consistency” problem, and verifying re-inspection solves the “report and实物 consistency” problem. Only after completing all four steps is the on-site quality gate secured.

8.4 The “Five Keys” of System Compliance

8.4.1 Key One: Bonding Agent Compliance

The bonding agent is the “bridge” between flexible stone and substrate. If the bonding agent is non-compliant, even the best flexible stone is useless. Special flexible stone bonding agents must be used; bonding agent test reports must be complete; compatibility between the bonding agent, flexible stone, and substrate must be verified.

Table 8-7 Bonding Agent Compliance Requirements

[11]

8.4.2 Key Two: Substrate Compliance

The substrate is the “foundation” of the flexible stone system. If the substrate is non-compliant, the system will inevitably fail. Substrate strength ≥0.3 MPa; substrate moisture content ≤10%; substrate flatness deviation ≤4 mm.

Table 8-8 Substrate Compliance Requirements

8.4.3 Key Three: System Fire Protection Compliance

Fire protection is a mandatory field, and system fire protection compliance cannot be omitted. Flexible stone combustion performance level meets design requirements; insulation system fire protection level meets code requirements; fire barriers and protective layers are in place.

Table 8-9 System Fire Protection Compliance Requirements

8.4.4 Key Four: Construction Compliance

Construction is a key link in system compliance. If materials are qualified and design is qualified but construction is not qualified, the system will still have problems. Construction processes comply with technical regulations; construction environment meets requirements (temperature, humidity, wind speed); construction records are complete and traceable.

Table 8-10 Construction Compliance Requirements

8.4.5 Key Five: Acceptance Compliance

Acceptance is the final gate of system compliance. If acceptance is non-compliant, all previous work is wasted. Bonding strength pull-off test qualified; hollowing rate ≤5%; appearance quality meets acceptance standards.

Table 8-11 Acceptance Compliance Requirements

Case: In a facade retrofit project, the bonding strength failed in the completion acceptance pull-off test. Investigation found that the construction team used ordinary ceramic tile bonding agent instead of special flexible stone bonding agent, and the measured substrate moisture content reached 14%, exceeding the 10% qualified upper limit. Subsequently, the special bonding agent was replaced, the substrate was dried, and construction was redone; re-inspection all passed.

Case insight: The five keys are indispensable. Wrong bonding agent, damp substrate, omitted construction, loose acceptance—any one link failing will cause the entire system to fail. System compliance must be managed from material procurement all the way to completion acceptance.

8.5 Practical Certification Process

8.5.1 China Green Building Materials Product Certification

Certification value: bonus points for green building projects; priority procurement for government projects; enhanced brand image.

Certification process: submit application materials (enterprise qualifications, product information, test reports); factory inspection (production site, quality management system); product testing (sent for testing according to certification rules); certification review (expert review, result determination); certification and supervision (annual supervision during certificate validity). The certification cycle is usually 3–6 months.

Table 8-12 Green Building Materials Certification Tiers

8.5.2 China Environmental Labeling Product Certification (Ten-Ring Certification)

Certification value: authoritative endorsement of environmental performance; bonus points for government procurement; enhanced consumer trust. The certification process is similar to green building materials certification, with more emphasis on environmental performance indicators.

8.5.3 Fire Protection Product Certification

Applicable situations: flexible stone used in high-rise buildings, public buildings, and other places with high fire protection requirements; combustion performance level test reports need to be provided. Certification points: tested according to GB 8624 standard; A2-grade products need to pass non-combustibility tests.

8.5.4 Certification Investment and Benefit Trade-Off

Certification testing requires investment of money and time, but also brings market access, bidding bonus points, brand premium, and risk avoidance benefits. Common cost inputs: type inspection about 20,000–50,000 RMB/time, green building materials certification about 30,000–80,000 RMB/item, fire protection product certification about 50,000–100,000 RMB/item. The certification cycle is usually 3–6 months, during which project opportunities may be missed—this is an opportunity cost that must be included.

The realization of certification benefits is often long-term: brand premium takes time to accumulate, and bidding bonus points require continuous application. Certification costs are irreversible: once invested in certification, even if the market changes or products are adjusted, the certification costs cannot be recovered. Therefore, certification investment should be regarded as a “strategic investment” rather than a “one-time expenditure,” and comprehensive decisions should be made in conjunction with the enterprise’s long-term development strategy. Through continuous production and multi-project application, certification costs can be gradually amortized in product unit prices.

8.5.5 The “Three Reminders” of Certification Practice

Reminder one: Confirm demand before certification. Different projects have different certification requirements. First understand the bidding documents and specification requirements to avoid blind certification wasting time and money.

Reminder two: Certification is not once and for all. Certification certificates have validity periods and require annual supervision audits. Product formula or process changes require re-certification.

Reminder three: Certification reports should be “used flexibly.” Proactively provide certification reports during bidding, explain the meaning and value of certification to customers, and use certification reports to respond to customer questions.

Case: A flexible stone enterprise invested in green building materials two-star certification in the early stage. After obtaining certification, it won two consecutive government facade retrofit projects, with the highest comprehensive score among similar products in bidding. After accounting, the enterprise believed that the certification investment had been fully recovered through bid-winning premiums and had established sustainable brand credit.

Case insight: Certification investment is not “paying money for a certificate,” but speaking with data. Confirm the target market demand before certification, and proactively use it for bidding and customer communication after certification, so that the value of certification can truly be realized as market returns.

8.6 Response Strategies for Areas with Missing Standards

8.6.1 The Reality of Standard Gaps

Flexible stone is a new material, and some application scenarios do not yet have dedicated standards covering them: high-rise building exterior wall insulation and decoration integrated systems; materials dedicated to historic building restoration; curved and irregular building decoration materials; renovation materials for special substrates (old ceramic tile surfaces, old coating surfaces).

8.6.2 Reference to Similar Standards

Reference standards for similar materials such as ceramic tiles, coatings, and stone; adopt the “strictest values” of various indicators as control standards; clearly agree on reference standards in contracts.

8.6.3 Enterprise Standards First

Formulate enterprise standards higher than industry levels; file on the enterprise standard information public service platform; proactively provide enterprise standards in bidding documents.

8.6.4 Special Demonstration

For special application scenarios, organize expert demonstrations; prepare special technical schemes; make up for standard gaps through demonstration reports.

8.6.5 Promote Standard Formulation

Participate in the formulation of industry standards and group standards; transform mature technical experience into standard clauses; occupy discourse power in standard formulation.

Table 8-13 Comparison of Response Strategies for Missing Standards

8.6.5 Promote Standard Formulation

Participate in the formulation of industry standards and group standards; transform mature technical experience into standard clauses; occupy discourse power in standard formulation.

Table 8-13 Comparison of Response Strategies for Missing Standards

Case: A historic building restoration project required exterior wall materials to maintain blue brick texture while not increasing structural load. Flexible stone texture matched, but there was no dedicated standard for historic building restoration. The material supplier adopted a combined strategy of “reference to similar standards + special demonstration”: technical indicators referenced JG/T 311 with the strictest values, and simultaneously organized special demonstrations by ancient building experts and material experts to form a special technical scheme. The project passed review smoothly.

Case insight: Standard gaps are not “cannot be done,” but finding a documented approach. Referencing similar standards with the strictest values, plus special demonstration, can both meet special scenario needs and accumulate case foundations for subsequent standard formulation.

8.7 Decision Reference for Facade Retrofit Offices

Key Decision Points of This Chapter

• The flexible stone standard system consists of four layers: product standards, system standards, fire protection standards, and environmental protection standards. Procurement and acceptance must simultaneously refer to product standards and system standards, not just material reports.
• On-site acceptance implements the “four-step verification method”: verify the report, verify the product, verify the batch, and verify re-inspection. Only after completing all four steps is the quality gate secured.
• System compliance locks in five keys: bonding agent compliance, substrate compliance, system fire protection compliance, construction compliance, and acceptance compliance. Failure of any link will cause system failure.

Compliance Check Items

8. Verify whether JG/T 311 and JC/T 2219 product test reports are complete and valid, and whether the testing institution has CMA qualification.
9. Verify the implementation of system standards; facade retrofit external insulation projects should perform substrate interface treatment according to JGJ 144 requirements.
10. Verify whether combustion performance reports and environmental protection test reports are complete, and whether high-rise and densely populated places meet A2 requirements.
11. Verify whether the batch numbers of incoming products correspond to test reports, and whether the same facade uses the same batch.
12. Conduct on-site re-inspection of key indicators such as bonding strength and combustion performance according to regulations; batches failing re-inspection must be resolutely returned.

Cost Reference Range

4. Type inspection about 20,000–50,000 RMB/time, green building materials certification about 30,000–80,000 RMB/item, fire protection product certification about 50,000–100,000 RMB/item; specific costs are based on quotations from certification and testing institutions.
5. The certification cycle is usually 3–6 months, during which project opportunities may be missed; this should be included in decision-making as an opportunity cost.
6. Certification investment is a strategic investment and can be gradually amortized through continuous production and multi-project application.

Risk Warnings

7. Product qualification does not equal system qualification; ignoring system standards may lead to quality accidents such as hollowing and detachment.
8. Only checking one report on site and not looking at the full set can easily miss combustion performance and environmental protection indicators, causing acceptance blockage or rework.
9. Using ordinary ceramic tile bonding agent instead of special bonding agent and substrate moisture content exceeding standards are high-frequency causes of system compliance failure.
10. Areas with standard gaps cannot be left unmanaged; reference to similar standards with the strictest values or special demonstration should be adopted to avoid “no basis” acceptance risks.

Replicability Judgment

6. Flexible stone is a “mature category with standards” and can be standardized and promoted to facade retrofit exterior wall projects after completing full-set test report verification and system compliance briefings.
7. Special application scenarios (historic building restoration, curved and irregular buildings, etc.) require strategies such as “reference to similar standards + special demonstration” or “enterprise standards first,” and can be promoted only after confirming control indicators.

Reflections on Stone, Insights on Fortune

Standard certification is not “icing on the cake” but “timely assistance.” Standards are the bottom line, certification is the threshold, and acceptance is the gate. When the bottom line is held, the threshold is crossed, and the gate is secured, the project is stable.

References

[1] Ministry of Housing and Urban-Rural Development. Flexible Facing Brick: JG/T 311-2011[S]. Beijing: Standards Press of China, 2011.

[2] Ministry of Industry and Information Technology. Modified Inorganic Powder Composite Building Facing Sheet: JC/T 2219-2014[S]. Beijing: China Building Materials Industry Press, 2014.

[3] Ministry of Housing and Urban-Rural Development. Technical Standard for Exterior Wall External Insulation Engineering: JGJ 144-2019[S]. Beijing: China Architecture & Building Press, 2019.

[4] Ministry of Housing and Urban-Rural Development. Standard for Construction Quality Acceptance of Building Decoration: GB 50210-2018[S]. Beijing: China Architecture & Building Press, 2018.

[5] Ministry of Housing and Urban-Rural Development. Standard for Construction Quality Acceptance of Building Energy Conservation Engineering: GB 50411-2019[S]. Beijing: China Architecture & Building Press, 2019.

[6] General Administration of Quality Supervision, Inspection and Quarantine, Standardization Administration of China. Classification for Burning Behavior of Building Materials and Products: GB 8624-2012[S]. Beijing: Standards Press of China, 2013.

[7] Ministry of Housing and Urban-Rural Development. Code for Fire Protection Design of Buildings: GB 50016-2014 (2018 Edition)[S]. Beijing: China Planning Press, 2018.

[8] Ministry of Housing and Urban-Rural Development. General Code for Building Fire Protection: GB 55037-2022[S]. Beijing: China Architecture & Building Press, 2022.

[9] State Administration for Market Regulation, Standardization Administration of China. Limit of Harmful Substances in Wall Coatings for Buildings: GB 18582-2020[S]. Beijing: Standards Press of China, 2020.

[10] General Administration of Quality Supervision, Inspection and Quarantine, Standardization Administration of China. Limits of Radionuclides in Building Materials: GB 6566-2010[S]. Beijing: Standards Press of China, 2010.

[11] Ministry of Housing and Urban-Rural Development. Standard for Testing Bonding Strength of Facing Tiles in Building Engineering: JGJ/T 110-2017[S]. Beijing: China Architecture & Building Press, 2017.