Which type of fiberglass felt should the waterproof building materials industry choose?
In the current era of rapid development in the building waterproofing industry, lightweighting, weather resistance, and long-lasting corrosion resistance have become core directions for the upgrading of waterproofing materials. Traditional non-woven fabrics and ordinary fiberglass felts have shortcomings such as susceptibility to rot, insufficient tensile strength, and poor adaptability to high and low temperatures. In contrast, waterproof-specific fiberglass felts, with their advantages of strong chemical stability, tensile and crack resistance, acid and alkali resistance, and excellent breathability, have become the standard reinforcing substrate for modified bitumen rolls, polymer waterproof sheets, roof waterproofing, tunnel seepage prevention, and wall damp-proofing.
Waterproof building material-specific fiberglass felts are ultra-thin non-woven fiberglass products made from alkali-free glass fiber, which is chopped, evenly laid, and bonded with a special water-resistant emulsion adhesive through wet molding and high-temperature curing. Unlike ordinary fiberglass felts used for insulation, soundproofing, and filtration, the waterproof version has been specifically optimized in terms of formula, weight, adhesive, and water resistance, making it fully suitable for complex construction environments such as outdoor exposure, underground dampness, and acid and alkali corrosion.
Based on raw material composition, waterproof fiberglass felt is primarily alkali-free fiberglass felt, boasting superior overall physical and chemical properties. It exhibits stronger insulation, weather resistance, and aging resistance, and is chemically stable, making it less susceptible to erosion by rainwater and saline-alkali soils. Its production cost is relatively higher, and it is widely used in high-standard projects such as high-end building waterproofing, rooftop planting waterproofing, tunnel and subway seepage prevention, and chemical plant anti-corrosion waterproofing. It is suitable for composite use with polymer waterproof coatings, TPO, and PVC polymer waterproof membranes.
Based on functional structure and manufacturing process, waterproof fiberglass felt on the market is further divided into ordinary plain felt, coated fiberglass felt, and flame-retardant fiberglass felt. Ordinary plain fiberglass felt focuses on base reinforcement, improving the tensile and crack resistance of the waterproof material, and is mostly used for indoor damp-proofing and ordinary roof waterproofing. Coated types have a composite waterproof coating on the surface, offering stronger impermeability and seepage prevention performance, suitable for long-term damp environments such as underground garages and basements. Flame-retardant types add special flame-retardant additives to meet the waterproofing requirements of factories, warehouses, and other projects with fire protection needs, addressing both waterproofing and fire protection requirements.
The core indicators for evaluating the quality of waterproof fiberglass felt are also the key criteria for material selection. First is weight. Common specifications in the waterproofing field range from 50g/㎡ to 120g/㎡. Lower weight means a lighter and thinner texture, suitable for wall damp-proofing and paint lamination; higher weight felts have stronger tensile strength and are often used as a base for roll materials and for roof waterproofing. Second is water resistance and bonding strength. High-quality waterproof felt uses waterproof acrylic emulsion bonding, which does not powder or delaminate after long-term water immersion, preventing the waterproof layer from falling off and breaking later.
Simultaneously, dimensional stability is also crucial. High-quality fiberglass felt has a low heat shrinkage rate and will not shrink or deform under high-temperature exposure or low-temperature freeze-thaw conditions, effectively restraining the deformation of the waterproof material and preventing cracking and blistering of the waterproof layer. In addition, it has uniform tensile strength in both directions and moderate breathability, which can resist the tensile stress caused by structural settlement while allowing moisture from the substrate to escape, preventing blistering and damage to the waterproof layer.
In practical applications, this material is suitable for a wide range of scenarios. Modified bitumen waterproof membranes laminated with fiberglass felt enhance the membrane's resistance to aging and UV radiation, extending the lifespan of roof waterproofing. When waterproof coatings are applied, fiberglass felt is laminated to form a composite waterproof layer, addressing the drawbacks of pure coatings such as poor tensile strength and susceptibility to cracking. In underground utility tunnels and municipal tunnel waterproofing projects, fiberglass felt acts as an isolation and reinforcement layer, resisting soil acid and alkali corrosion and strengthening seepage prevention.
As the invisible framework of building waterproofing, specialized fiberglass felt, while lacking complex manufacturing processes, provides a solid foundation for building waterproofing through its customized material ratios and performance design. Choosing the right fiberglass felt for the specific application and controlling key parameters such as weight, material, water resistance, and tensile strength are crucial for improving the stability of the waterproofing layer from the outset, reducing potential leaks and maintenance issues, and ensuring long-lasting and durable building waterproofing.
