What is a torus moulding?
A torus is a large, convex, roughly semicircular moulding that runs around a building element, usually at the base of a column or pilaster. The word comes from Latin and means something like cushion or swelling. In section, a torus looks like a thick ring lying on its side: it projects outwards and therefore catches light and casts shadow.
Shape and recognition
- Large and convex: a torus is clearly bigger than an astragal (bead), which is also semicircular but much slimmer.
- Paired with a hollow: in the classical column base, a torus is often combined with a scotia (trochilus), a deep concave moulding. The alternation of convex and concave creates the typical play of shadow.
- Attic base: the best-known use is the Attic base: a large torus at the bottom, a scotia above it and a smaller torus on top. You will see it on Ionic and Corinthian columns and on many Neoclassical buildings.
- Tuscan base: in the plain Tuscan order the shaft often stands on a single torus above a plinth.
Where it is used
- Bases of columns, pilasters and half-columns in stone, timber or plaster.
- Mouldings along plinths, socles and string courses.
- Interiors: skirting boards, fire surrounds and door architraves with a torus profile. “Torus skirting” is still a common profile name in UK joinery.
Maintenance and restoration tips
- A torus at the foot of an external column catches a lot of rain splash. Check for spalling, frost damage and loose pieces.
- When repairing stone: have the profile recorded with a template so the new piece matches exactly.
- For timber mouldings, a router cutter with the correct radius saves a lot of sanding.
Related terms
- Column base
- Column
- Doric
- Baluster
- Plaster base
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