Fire acceptance always gets stuck? Fireproof rock wool selection guide dry information sharing

Shengyuan Refractory and Insulation Materials Factory has been deeply involved in the fire retardant and thermal insulation material industry for 20 years, and has been responsible for the procurement of construction, steel structure, and industrial pipeline projects all year round. Fire protection and exterior wall insulation regulations will continue to tighten in various places in 2026. Many purchasers and construction parties only base their judgment on price and appearance when selecting fireproof rock wool. Later, problems such as insulation failure, fire acceptance failure, and wall falling off will occur . This article combines national standards and front-line engineering experience to completely dismantle the entire selection process of fireproof rock wool to avoid hidden procurement risks.

1. Misunderstandings in model selection

The three most common cognitive biases when purchasing fireproof rock wool are also the main causes of project rework.

1. It is believed that all fire-resistant rock wool have the same fire-resistance level . They only read the labels without verifying the CMA test report. Low-priced non-standard products are mixed with a large amount of organic binders and are nominally labeled A-level. The actual fire-resistant time is greatly reduced, and they cannot pass the fire acceptance.

2. A single price comparison ignores the comprehensive cost. Many purchases give priority to low-priced and low-density fireproof rock wool. The fibers are loose and the compression and tensile strength are not up to standard. The exterior walls delaminate after 1-3 years of use and fail to absorb water in humid environments. The later maintenance and secondary replacement costs far exceed the initial price difference.

3. The universal model can be used in all scenarios, regardless of indoor and outdoor walls, dry and wet environments. Ordinary non-hydrophobic treated fireproof rock wool is used in basements and outside curtain walls. The thermal conductivity will soar due to long-term moisture exposure, and both fire prevention and thermal insulation will fail.

The three types of misunderstandings all stem from unfamiliarity with the core parameters of fireproof rock wool and relying solely on verbal introductions from merchants to make decisions.

2. Selection criteria

To select qualified fireproof rock wool, five rigid standards must be locked in , and construction can only begin if all standards are met.

1. Combustion performance standards : Must have a Class A non-combustible test report issued by the CMA agency. The raw material is mainly basalt, with a melting point of over 1000°C, no melting and dripping at high temperatures, and no toxic smoke. It complies with GB8624-2012 specifications.

2. Density and mechanical strength : 100-120kg/m³ for civil interior walls, 140-180kg/m³ for exterior walls and curtain walls, vertical tensile strength ≥10kPa, to avoid negative pressure falling off.

3. Thermal conductivity : ≤0.040W/(m·K) at room temperature of 25°C, ensuring long-term thermal insulation and energy-saving effects and reducing building energy consumption.

4. Hydrophobic durability index : The hydrophobic rate of fireproof rock wool in outdoor and humid areas is ≥98%, the acidity coefficient MK≥1.6, it is corrosion-resistant and weather-resistant, and its service life matches the main body of the building.

5. Qualification compliance standards : Manufacturers have industrial production licenses, building materials registration, provide complete certificates, and batch test reports to eliminate the problem of 'three no samples' and incorrect goods.

The five major standards are indispensable. Failure to meet any of the standards will cause the fireproof rock wool to lose its safe use value.

3. Product comparison

The mainstream fireproof rock wool on the market is divided into three types: general purpose, high-density exterior wall, and water-repellent and moisture-proof. Each has its own suitable scene, so you can choose according to your needs.

General standard fireproof rock wool : density 100-120kg/m³, Class A basic fireproof, easy to cut and affordable. The construction is simple and suitable for indoor partition walls, computer rooms, and indoor pipelines; it is not resistant to moisture and has weak tensile strength, so it cannot be used for sealing high-rise exterior walls and curtain walls, and is only suitable for low-rise indoor fire separation.

High-density exterior wall fireproof rock wool : Density 140-180kg/m³, dense structure, fire resistance limit of more than 3 hours, tensile and compression resistance, wind pressure resistance, good sound insulation, conforms to exterior wall insulation specifications, suitable for high-rise, steel roofs, and curtain walls; it has a large weight, is slightly difficult to cut, and is more expensive. It is mostly used in high-standard exterior wall insulation projects.

Water-repellent, moisture-proof and fire-proof rock wool : modified with silicone, the water-repellent rate exceeds 98%, and the thermal insulation performance is stable in a water vapor environment. It is suitable for humid areas such as coastal areas, basements, and exhaust pipes. The process is complex and the price is high. Use in dry rooms will cause cost waste.

All three models achieve Class A fire protection. The difference lies in mechanical strength and moisture-proof ability. Please confirm the construction environment before purchasing to prevent insufficient performance or waste of cost.

4. Recommended solutions

Fireproof rock wool is matched according to the engineering scenario, taking into account compliance, cost and durability. For low-rise indoor and computer room partitions, if you are pursuing basic fire protection and thermal insulation, choose 50-80mm general fireproof rock wool, which is more cost-effective. For exterior wall and curtain wall sealing of high-rise buildings and steel-structured factories, 80-100mm high-density vertical wire fireproof rock wool is used, which has strong tensile strength and prevents the surface layer from falling off, making it easy to pass the exterior wall acceptance. In humid scenes such as coastal areas, basements, and smoke exhaust ducts, hydrophobic fireproof rock wool is suitable to resist water vapor erosion. Thermal and HVAC pipes can be matched with fireproof rock wool pipe shells of the same specification. For multi-area composite projects, corresponding fireproof rock wool can be selected in different zones to balance costs and fire safety standards.

5. Ending

The 2026 fire protection regulations are constantly being updated. Projects in various regions have different requirements for fire protection rock wool parameters and testing data. It is easy to make mistakes in selection based on article reference alone. Shengyuan Refractory Insulation Materials Factory has a full range of fireproof rock wool in stock and can provide free parameter calculations, supporting solutions and a full set of qualification reports. If you have procurement needs for exterior walls, curtain walls, pipes, and basement fire protection projects and are unsure about the model, you can leave a message in the background to inform the project conditions, floor height, and budget. The technical specialist will customize an exclusive selection plan, provide construction guidance, and assist in preparing fire protection acceptance materials to avoid various procurement and construction problems.