Glass Fibre Reinforcement Mesh in EIFS: 6 Technical Parameters For Specification

The alkaline environment of Portland cement can degrade ordinary glass fibres within months. Specify alkali-resistant (AR) glass fibre with zirconium dioxide (ZrO₂) content of 14.5–16.7% in the glass composition. The key performance metric is alkali-resistant tensile strength retention-quality products retain over 90% of their original strength after alkali exposure per ASTM E2098 or ISO 10587 test methods. For EIFS applications, leading product standards such as EN 13500 specify minimum retention rates, with 90% retention considered the professional benchmark for high‑durability projects.

This is the mesh's ability to resist cracking under stress. Specify minimum tensile strength in both warp and weft directions per ASTM E2098 or EN 13496 test methods. For professional EIFS applications, specify at least 1300 N/50mm for standard‑duty mesh and 2000 N/50mm for heavy‑duty applications-performance levels that meet or exceed the requirements of international building codes.

Mesh weight directly correlates with strength and durability. Standard EIFS mesh typically requires ≥160 g/m², with heavy‑duty options at ≥280 g/m². Lighter meshes may meet minimum specifications but offer significantly less crack protection. Specify grammage clearly-this is one of the most common points of substitution in the supply chain.

The grid dimensions affect mortar penetration and stress distribution. Standard EIFS mesh typically uses 4×4 mm or 5×5 mm openings. Smaller openings (4×4 mm) provide denser reinforcement for higher crack resistance, while 5×5 mm openings offer a balance of reinforcement and mortar flow‑through. Specify the opening size based on the project's crack control requirements.

The mesh must maintain its geometry under thermal and mechanical stress. Specify high elastic modulus (quality AR glass achieves approximately 80 GPa) and strain at breaking point below 1%. These properties ensure the mesh distributes stress evenly rather than deforming or tearing under load. Also confirm the mesh is dimensionally stable-it should not stretch, shrink, or warp during installation or service.

The mesh must be fully encapsulated in the base coat mortar to function properly. Specify base coat thickness in the range of 1.6 mm to 6.4 mm dry thickness, depending on the number of mesh layers. Also specify minimum overlap at joints-typically ≥50 mm at flat joints and corners, and ≥200 mm at outside corners-in accordance with internationally recognized EIFS installation best practices. The mesh should be embedded in the base coat with 100% mortar saturation-no wrinkles, no exposed fibres, and no voids.