While Glass Mat Gypsum (GMG) sheathing remains a traditional baseline for commercial exterior walls, High-Density Magnesium Oxide (MgO) Sheathing Board is rapidly emerging as the superior architectural alternative. Offering zero-combustibility (Class A1/ASTM E136), higher structural shear capacity, exceptional moisture resistance, and direct-fastener retention, High-Density MgO eliminates core degradation risks during extended site exposure.
Technical Performance Matrix: MgO Sheathing vs. Glass Mat Gypsum
To assist structural engineers, facade consultants, and procurement managers in material evaluation, the table below outlines the core physical and mechanical parameters based on standard industrial testing:
| Performance Metric | High-Density MgO Board (≥1,000kg/m3) | Glass Mat Gypsum Board (ASTM C1177) |
| Material Composition | Crystalline MgO Matrix + Alkali-Resistant Glass Mesh | Desulfurized Gypsum Core + Fibrous Glass Mat Facing |
| Core Density | 1,050 – 1,250 kg/m3 | 750 – 850kg/m3 |
| Fire Reaction Class | Non-Combustible (ASTM E136 / EN 13501-1 A1) | Fire-Resistant Core (ASTM C1177 Type X) |
| Flexural Strength (Dry) | ≥18 – 22 MPa | ≈approx 6 – 8MPa |
| Flexural Retention (Saturated) | ＞85% Flexural Capacity | Rapid Softening & Core Breakdown under Hydrostatic Load |
| Fastener Pull-Out Strength | Superior Direct Screw Anchoring Strength | Requires Structural Stud Framing Anchoring |
| Mold & Biological Resistance | Inorganic Alkaline Matrix (pH 10-11) – Zero Growth | Resistant Facing, but Sensitive Gypsum Core |
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2026
NOV
2026
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