Strength band
paper faces take bending; wet boards are scrap
Darker cells mean a higher score for this topic on that metric.
Strength24
Heat resistance54
Fire performance92
Insulation34
Workability90
Circularity62
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Quick answers
Is Gypsum board non-combustible?
Declared reaction class in this atlas: A2-s1,d0 typical; core A1. Assemblies still need resistance tests.
Does Gypsum board insulate?
Thermal mark 34/100 versus the atlas. Conductivity note: ~0.17 W/m·K.
What is the density band?
~700–1000 kg/m³
How is it made?
Origin story: Sackett 1894; US Gypsum 1916 (United States).
Can it be recycled?
Circularity mark 62/100 — editorial, route-specific.
Typical melting or failure heat?
calcines ~80–180 °C (dehydration)
heat 54 · fire 92
Numbers below are bands used by working engineers, not live quotes. Tensile note: paper faces take bending; wet boards are scrap.
Fire performance in this atlas is editorial. Real projects need the assembly report.
Mechanical
Stiffness
Modulus follows chemistry and orientation — not the marketing nickname.
Toughness
Crack growth, not peak stress, retires most real parts.
Fatigue / creep
Cyclic and time-dependent damage dominate certificates issued on static coupons.
Hardness / hand
Indentation, drape or compressive class — whichever the trade actually measures.
Thermal
Conductivity
~0.17 W/m·K — Gypsum board is not a substitute for a dedicated λ layer.
Service temperature
Melting / softening / decomposition band: calcines ~80–180 °C (dehydration).
Expansion
Joints and clearances must follow the expansion class of Gypsum board, not of steel-by-habit.
Thermal mass
Density ~700–1000 kg/m³ sets how fast a section changes temperature.
Ageing of λ
Foams, VIPs and moist batts drift; quote aged values.
Electrical
Conductor or dielectric
Gypsum board is generally a dielectric or semiconductor film, not building wire.
Static / EMI
Fillers and moisture change resistivity more than brochures admit.
Standards language
IACS, volume resistivity or dielectric strength — pick the quantity the job uses.
Fire
Reaction to fire
Typical declared class: A2-s1,d0 typical; core A1. This is not a universal passport.
Resistance vs reaction
Euroclass is reaction. EI/R ratings are assemblies — boards, coats, cavities.
Melt-drip / char
Gypsum board tends to char or stay inorganic rather than melt-drip like commodity olefins.
Smoke / toxicity
CO, HCN, HF or fibres — the species depend on chemistry. Name the test (ISO 5659, EN 45545, NFPA 1971).
If a salesperson quotes a single “safety score”, ask which standard, which thickness, which year.
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