Gypsum Block Calculator: Complete Reference
Gypsum Block Basics
Gypsum blocks are prefabricated partition units made from calcined gypsum and water, cast into 500×250mm face blocks in thicknesses of 60–200mm. Density: 900–1100 kg/m³. Compressive strength: 2–5 MPa (partition only). Not for load-bearing or external use.
Key advantages: inherent fire resistance (EI 30–120+), good sound insulation (Rw 35–45 dB for single leaf), fast installation (dry adhesive), smooth surface ready for direct painting, and 100% recyclable.
Fire & Sound Performance
Fire resistance: gypsum blocks release chemically-bound water as steam at ≈150°C, absorbing heat and delaying temperature rise. 100mm solid gypsum: EI 60. Fire resistance scales approximately linearly with thickness.
Sound: Rw ≈ 20·log₁₀(m·f) − 47 (mass law). A 100mm block wall (105 kg/m²) achieves Rw ≈ 40 dB. Double-leaf with cavity: up to Rw 55 dB.
Installation Guide
Use gypsum adhesive (8 kg/m²). Apply glue ribbons to block edges and press into position. Install perimeter sealant at floor, ceiling, and wall junctions for acoustic performance. Blocks interlock with tongue-and-groove profile — no vertical bed joints on perpendicular rows.
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FAQs
Can gypsum blocks be used in wet areas?
Standard gypsum blocks should not be used in constantly wet areas (bathrooms, wet rooms). Moisture-resistant variants (green-labelled) tolerate occasional splashing but require waterproof membrane and tiling.
How many gypsum blocks per m²?
Standard 500×250mm face block: 8 blocks/m². Account for 5% waste for standard installations, 10% for complex layouts with cuts.
What adhesive is used?
Proprietary gypsum adhesive powder (mix with water). Apply ~8 kg/m². Setting time: 20–30 minutes. Pot life after mixing: 15–20 minutes — mix small batches.