Moisture Resistant Rock Wool Boards Suitable For Humid Area Installations
Product Specifications
| Attribute | Value |
| Density | 40 - 200 kg/m³ |
| Color | yellowish-brown |
| Stock Size | 1200×600(mm) |
| Thickness | 30mm-150mm |
| Electrical Insulation | Good |
| Noise Reduction | Good |
| Fireproofing | Good |
| Hydrophobic Property | Good |
| Temperature Resistance | -268℃ ~ 650℃ |
| Surface Finish | Rough |
Product Description
Rock wool boards are inorganic thermal insulation materials made from natural rocks like basalt and diabase, processed through high-temperature melting and fiberization. Their core advantages lie in thermal insulation, fire resistance, and sound insulation, but they are not inherently water-resistant—water resistance relies on material modification or structural design.
Raw rock wool has a porous fibrous structure (porosity over 90%) and strong hygroscopicity; it absorbs moisture via capillary action, which increases weight, reduces insulation performance, and may soften the board over time. However, its hydrophobicity can be adjusted: adding hydrophobizing agents (e.g., silicone-based reagents) during production creates "hydrophobic rock wool boards," which form a water-repellent film on fibers to reduce moisture absorption. Per China’s GB/T 19686-2017, such boards need a hydrophobic rate ≥98% and volume water absorption ≤5%, meeting most moisture-proof needs in construction, though they still cannot resist continuous water pressure or long-term immersion. Enhancing their water resistance requires combining methods like surface coating with waterproof membranes/coatings, sealing joints with waterproof sealants (e.g., silicone sealants), and adding drainage structures (e.g., roof gutters) to remove seepage.
Performance
In construction, rock wool boards are mainly used in scenarios demanding high fire resistance, with supporting waterproof designs. For external wall insulation (common in high-rises, public buildings like malls and hospitals, and fire-sensitive residences), they are typically part of external thermal insulation systems. The structure includes a base wall, adhesive layer, hydrophobic rock wool board, rendering mortar layer (with alkali-resistant glass fiber mesh), and finish (paint or dry-hung stone). Paint finishes often add anti-crack waterproof putty. They reduce heat transfer to cut energy use and block fire spread, but require staggered board laying to avoid straight seams, sealing joints over 2mm with insulation strips and sealant, and adding turned-up edges or drip lines at water-prone areas like windowsills.
For roof insulation, high-density hydrophobic rock wool boards (compressive strength ≥80kPa) suit flat or sloped roofs. Flat roofs use a structure of structural layer, slope-finding layer, leveling layer, waterproof layer, isolation layer, hydrophobic rock wool board, and protective layer; inverted roofs (waterproof layer under insulation) need more hydrophobic boards. Sloped roofs (with asphalt or ceramic tiles) have purlins, waterproof membranes, hydrophobic rock wool boards, roof panels, and tiles, requiring secure board fixing. These boards reduce roof heat transfer and boost rigidity for light loads like maintenance workers.
To sum up, rock wool boards’ core value is thermal insulation and fire resistance, with water resistance depending on hydrophobic modification and structural design. They should be prioritized for fire-sensitive areas like external walls and roofs, with waterproof plans adjusted by location. Using national standard hydrophobic boards (hydrophobic rate ≥98%) and ensuring strict joint sealing during construction is key to guaranteeing performance.
Waterproof Performance Comparison
| Material | Waterproof Principle | Water Absorption Rate | Applicable Environment | Limitations | Waterproof Lifespan |
| Hydrophobic Rock Wool Board | Hydrophobic treatment reduces water adsorption | ≤5% (≤3% for high-quality products) | High-humidity insulation scenarios | Requires combination with other waterproof layers | 15-20 years |
| Concrete | Dense structure formed by adjusting mix ratio | Impermeability grade P6-P12 | Structural waterproofing | May crack under stress | 10-30 years |
| Coating Types | Forms continuous waterproof film | Almost no water absorption | Small-area scenarios | Breathability/UV resistance issues | 10-15 years |
| Metal Materials | Non-absorbent by nature | 0% | Large venues | Joints prone to seepage | 20-50 years |
