Cast stone, or artificial stone, is the collective name for stone-like materials that do not occur in nature but are made by people. In the broad sense this includes brick, calcium silicate block, concrete block and gypsum block. In the narrower sense — the way the word is normally used in practice — it means a cast or pressed material that imitates the appearance of natural stone.
Note the name: cast stone is not plastic. It is a mineral mass, usually stone aggregate bound with cement or with a synthetic resin.
Two meanings
| Meaning | What it covers |
|---|---|
| Broad | All non-natural stone-like materials: brick, calcium silicate, concrete block, gypsum block |
| Narrow | Cast products imitating natural stone: aggregate bound with cement or with resin |
Where it is used
Cast stone in the second sense turns up mainly where natural stone is expensive or hard to obtain:
- Cills, copings and sub-cills — cast in concrete, often with a stone-like finish
- String courses and ornament — widely used in the first half of the twentieth century as a substitute for ashlar
- Worktops and window boards — composite of quartz or marble aggregate with a resin binder
- Restoration — where a weathered natural stone profile is recast
Points to watch:
- Frost resistance — for external use, ask for a product with demonstrated frost resistance
- Colour fastness — pigments in cement-bound cast stone can fade under UV light; compare samples that have already weathered
- Efflorescence — cement-bound cast stone can show lime bloom, particularly in the first months
- Keep resin indoors — resin-bound composite is not UV stable and does not belong outside
Related terms
- Natural stone
- Concrete block
- Calcium silicate block
- Brick
- Efflorescence
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