In fact, many customers ask anxiously during inquiries, "Will glass wool be ruined if it gets damp or wet from rain? As a professional exporter of glass wool and rock wool, United Insulation can give you the most authoritative answer:

1.Glass wool by itself does not absorb water nor does it rot.

Glass wool is made up of inorganic glass fibers, and its water repellency rate is more than or equal to 98% according to the national standard. Droplets would roll off just as on a lotus leaf. It does not absorb water like a sponge and also does not mold or breed bacteria.

2.The two actual effects of becoming wet are:

- Temporary loss of insulation performance: water fills the gaps between fibres, the thermal conductivity increases from 0.034 to 0.042 W/m·K up to almost 0.6, almost negligible insulation.

- Increased weight: The weight of 1 cubic meter dry glass wool is only 10–48 kg, but after absorbing water, the weight can amount to several hundred kilograms and generates sagging and shedding.

3.Performance is restored after drying!

When it is completely dried, either by air drying or low-temperature drying, the thermal conductivity, strength, and non-flammability will all return to their former values! That's far above that of a foam plastic, which, once water has entered an EPS/XPS, will never again be able to provide insulation.

4.Correct practices in practical application:

- Transportation and storage: Transportation and storage must be treated with waterproof plastic film and pallets to avoid rain damage.

- Exterior wall/roof construction: Breathable, waterproof breathable paper or aluminum foil lining is required.

- For the pipe insulation, a glass wool pipe shell with an outer protective layer should be installed to completely prevent the seepage of condensation.

All exported glass wool in United Insulation contains high-efficiency water-repellent agents. Their water repellency in the factory can achieve ≥ 99%. It offers a variety of linings, such as high-strength aluminum foil, FSK, and black tissue, truly achieving "not afraid of occasional rain."

 Summary: Glass wool will not get damaged when getting wet; it will only temporarily lose its insulation effect. When it gets completely dry, it will be as good as new! Choosing the right product and paying attention to the waterproofing details will give you complete peace of mind.

Need EU CE-certified glass wool rolls, boards, or pipe shells with a water repellency rate over 99%, or A1 non-combustible rock wool? Contact United Insulation – we make your insulation projects "wet-proof"!