How to determine the quality of external wall insulation materials? ——2026 Linyi Practical Judgment Guide

1、 Official testing standards: Three core indicators that must be verified

|Testing items | Execution standards | Judgment criteria | Testing methods|

|Thermal conductivity | GB/T 10294, GB/T 10295 | The lower the value, the better the insulation performance. High rise buildings require ≤ 0.040 W/(m · K) | Laboratory heat flow meter method or protective hot plate method, requiring a constant temperature steady-state environment|

|Combustion performance level | GB 8624-2012 | Class A (non combustible) is a mandatory requirement, and it is strictly prohibited to use B2/B3 grade materials for exterior walls | Single body combustion test (SBI), non combustible test, smoke toxicity test|

|Tensile strength | JGJ 144-2019 | Tensile strength of rock wool board perpendicular to the board surface ≥ 0.10 MPa | Universal testing machine pull test, sample needs to be cured for 28 days|

✅ Key reminder: All materials must provide a third-party testing report stamped with CMA seal before entering the site, and the testing items should fully cover the above three core indicators.

2、 Five step method for quick on-site judgment (practical skills for construction personnel)

Look at the appearance

Rock wool board: uniform light yellow color, without obvious black spots or white blocks; The surface is smooth, without cracks, delamination, or peeling.

XPS board: The surface is dense and smooth, with a uniform closed cell honeycomb like cross-section and no obvious particle sensation.

Foam ceramic board: Consistent color, no pores or cracks, neat edges, and no missing corners.

Touch the texture

Rock wool: gentle and elastic, capable of slight rebound, with fine fibers and no coarse residue; Poor quality products are tight, hard, and inelastic, with a rough texture and easy to fall off.

XPS: High hardness, no indentation when pressed; If it collapses and deforms, recycled materials may be added.

Foam ceramics: heavy and hard, with a crisp sound when struck; Light floaters are counterfeit products.

Density measurement

The density of rock wool should be ≥ 120 kg/m ³ (recommended ≥ 140 kg/m ³ for high-rise buildings);

Calculate using an electronic scale and tape measure: density=mass ÷ volume.

Those with densities lower than the standard have severely inadequate insulation and compressive performance.

Simple combustion test (limited to small samples, in a safe environment)

A-grade materials (rock wool, ceramics): non combustible upon contact with an open flame, self extinguishing upon ignition, and no melting droplets.

B1 level (modified EPS/XPS): self extinguishing within 10 seconds after leaving the fire, without sustained combustion.

B2/B3 level: Continuous combustion, droplets, thick smoke, strictly prohibited for use on exterior walls.

⚠️ It is strictly prohibited to ignite a large area on the construction site! Only limited to small-scale testing in a ventilated area after sampling.

Check labeling and packaging

The product should be labeled with: execution standard number (such as GB/T 25975), combustion grade, production date, manufacturer name, and certification number;

The packaging should be complete, accompanied by a factory certificate of conformity and a copy of the inspection report;

Products without identification or unclear information are considered unqualified.

3、 Four step method for verifying the authenticity of test reports

|Steps | Operations | Tools/Channels|

|1. Check the CMA logo | The cover or homepage of the report must have the "CMA" China Metrology Certification logo | No CMA=Invalid report|

|2. The verification number | report number, testing institution name, and sample number must be clear and distinguishable | compared with the inspection record|

|3. Platform Verification | Log in to the National Certification and Accreditation Information Public Service Platform（ http://cx.cnca.cn ）|Enter report number+institution name to query|

|4. Phone confirmation | Call the official phone number of the testing agency (not the private number left on the report) | For example: 010-51167679 (some agencies)|

Linyi local verification: You can log in to the "Shandong Province Building Energy saving Technology Product Application Certification Platform" to check whether the enterprise and product are in the Linyi City Housing and Construction Bureau's registration list.

4、 Linyi City Key Supervision and Prohibition List (to be implemented in 2026)

|Category | Prohibited/Cautious Materials | Alternative Recommendations | Policy Basis|

|System type | Insulation mortar, expanded perlite board, adhesive powder polystyrene particles | Integrated insulation structure (JTD template), rock wool/ceramic board | Linjian Anzhi Center [2019] No. 6|

|Material grade | B2 EPS, B3 polyphenylene foam | A rock wool, foam ceramic, aerogel | GB55037-2022|

|Construction method | Adhesive only, no anchoring system | Full adhesive+anchor bolts (≥ 10 pieces/㎡) | Linyi local supplementary standard|

|Source of Materials | "Three Nos" Products without Filing or CMA Report | Select Enterprises Publicized by Linyi Housing and Urban Rural Development Bureau (such as Shanghai Energy Conservation and Wanhua) | 2024 Public List|

Typical issues reported in Linyi in 2024:

Three projects use "pseudo A-grade" rock wool (actually slag wool, with excessive slag content);

The XPS board density of two projects is only 80 kg/m ³ (standard ≥ 120);

One project had no fire isolation zone and was ordered to rework.

Note: The above pictures are real material cross-sections, post combustion states, and comparison of construction sites, which can visually identify the authenticity of rock wool, inferior XPS, and qualified foam ceramic panels.

5、 Ultimate Judgment Formula (Essential for Linyi Engineering Personnel)

Three looks, three checks, and one verification

Check color, section, packaging, standards, reports, records, verify CMA, platform, and make phone calls

Remember: in Linyi, A-level is the bottom line, filing is the red line, and testing is the lifeline. ‌

Don't believe in 'cheap', trust official announcements and traceable reports.

Shandong Huaneng Insulation Materials Co., Ltd. is a pipeline insulation manufacturer in Linyi. As an integrated insulation and decoration manufacturer in Shandong, our main products include integrated insulation and decoration, pipeline insulation, exterior wall insulation materials, extruded polystyrene board, thermosetting polystyrene board, and rubber insulation. If you need it, you can contact us by phone.