Rock wool, a widely used basic material in modern building insulation, industrial equipment insulation, and fire protection systems, has technical parameters that directly determine its ability to meet engineering requirements. Understanding the core parameters of rock wool is crucial for ensuring project safety and stability for procurement, design, and construction teams. This article systematically breaks down the technical parameters of rock wool from three perspectives: basic parameters, performance indicators, and industry standards, providing a reference for engineering procurement and selection.

I. Core Physical Performance Parameters of Rock Wool

1. Bulk Density (kg/m³)

The bulk density of rock wool generally ranges from 40 to 180 kg/m³, depending on the application.

External wall insulation: Generally 80–120 kg/m³

Fireproof insulation strip: Usually above 120 kg/m³

Industrial equipment insulation: Mostly 100–150 kg/m³

Higher bulk density generally results in better thermal conductivity and compressive strength, but cost and construction load-bearing capacity must be considered.

2. Thermal Conductivity (W/m·K)

This is a key indicator for measuring thermal insulation performance. Common thermal conductivity of rock wool:

0.037–0.043 W/m·K (at room temperature)

Main factors affecting thermal conductivity include fiber uniformity, density, and moisture content.

3. Water Repellency (%)

Water-repellent rock wool needs a water repellency rate ≥98%, which is especially important for preventing condensation in building exterior walls and steel structure roofs.

Water-repellent treatment prevents the material from absorbing water, which can lead to performance degradation.

4. Moisture Absorption (%)

Conventional rock wool ≤1.0%. Excessive moisture absorption will affect thermal conductivity and durability.

Rock Wool Board

II. The Mechanical Parameters of Rock Wool are of Great Significance to Engineering

1. Compressive Strength (kPa)

Exterior wall rock wool boards generally have a compressive strength of ≥40kPa, roofing rock wool ≥60kPa, and industrial insulation ≥80kPa.

Compressive strength determines the material's ability to remain undeformed under load.

2. Pull-out Strength (kPa)

Exterior wall rock wool needs to have a tensile strength of ≥10kPa to ensure proper adhesion and prevent detachment.

III. Fire Resistance is Rock Wool's Greatest Advantage

Rock wool is a Class A non-combustible material, with a high temperature resistance of 600–1000°C.

Its key fire resistance parameters include:

Non-combustibility rating: Class A

Does not produce toxic fumes

Low high-temperature shrinkage

These properties make it widely used in: exterior wall fireproofing, pipe fireproofing, equipment insulation, and fire-resistant barriers.

Rock Wool Board

IV. Acoustic Technical Parameters of Rock Wool

Sound Absorption Coefficient NRC: 0.80–1.00 (depending on thickness and density)

Excellent performance in noise reduction projects for cinemas, computer rooms, and factories.

V. Mainstream Standards for Rock Wool

GB/T 25975 External Wall Insulation Rock Wool Board

GB/T 11835 Rock Wool for Industrial Buildings

EN 13162 European Standard Insulation Materials

Rock Wool Felt

Each technical parameter of rock wool corresponds to the actual engineering needs: thermal insulation, fire resistance, sound insulation, and durability. When selecting rock wool, it is essential to consider the application scenario and match indicators such as density, thermal conductivity, and strength. Mastering these parameters ensures more professional, safe, and reliable material selection for projects.