Gypsum board in 1894: Sackett Board
The behaviour of Gypsum board is written as 1894’s “Sackett Board,” fixed by 0. An advert’s adjective is not a melting point. “Room temperature” alone is not a figure. Gypsum board is sold as grades, not as a single substance. Chemistry CaSO4·2H2O + paper faces, density ~700–1000 kg/m³, heat band calcines ~80–180 °C (dehydration).
CaSO4·2H2O panels that buy fire time by calcining — the everyday A2/A1 lining of interiors. Gypsum board is one of 32 materials in this atlas, grouped under fire: history, structure, measured properties, process routes, uses, safety and market — not a product catalogue. Scores compare Gypsum board with the rest of the atlas on strength, heat, fire behaviour, insulation, workability and circularity. They are editorial, not certificates.
Seven chapters follow. Fire and insulation claims name test families (Euroclass, ASTM E84, ISO 5660, KS F) rather than inventing a single safety number. Gypsum board (CaSO4·2H2O + paper faces) is a family of grades whose density ~700–1000 kg/m³, heat band calcines ~80–180 °C (dehydration), and fire letter A2-s1,d0 typical; core A1.
This atlas treats Gypsum board as a system: mill route, coatings, tests and the cavity it sits in. Conductivity note: ~0.17 W/m·K. Insulation score 34/100 is relative to 32 entries — metals lose, VIPs and aerogels win. Fire letter in editorial use: A2-s1,d0 typical; core A1. Do not equate A1 with “safe in a blaze” or E with “illegal”. Assemblies decide.
“Sackett Board” for Gypsum board in 1894 carries 0. Praise without that figure is not a property.1894
Figures to keep
- Year of the condition
- 1894
- Property figure
- 0
- Material
- Gypsum board
- Use line
- Sackett Board
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