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 |
