Venetian terrazzo floor
A cast-in-place floor of marble and stone chips set in a cementitious binder, then ground and polished until the chips show and it becomes a continuous, mirror-like surface. Divided into fields by brass strips that control its cracking, it is a handcrafted, very hard and timeless floor — from Venetian palaces to contemporary interiors.
Technical section of the system, from inside (left) to outside (right).
A cast-in-place floor of marble and stone chips set in a cementitious binder, then ground and polished until the chips show and it becomes a continuous, mirror-like surface. Divided into fields by brass strips that control its cracking, it is a handcrafted, very hard and timeless floor — from Venetian palaces to contemporary interiors.
A Venetian terrazzo floor — seminato — is cast in place: marble (and other stone) chips are «sown» into a binder paste, compacted and left to cure, then ground and polished. The result is a continuous, stone surface where the chips emerge as in a fused mosaic.
The quality comes from two materials meeting: the chips, which give colour, hardness and pattern, and the binder — once lime, today often cement or resin — that holds them together. The chips are chosen by size and colour; the ratio of chips to binder and careful compaction decide the density and the look.
A continuous, rigid cement surface tends to crack with shrinkage and movement: so the floor is divided into fields by embedded brass (or zinc) strips, which act as joint and pattern at once. The strips take up the movement where the designer wants, avoiding random cracks, and break the pour into manageable bays.
The magic is in the finishing: the hardened cast is ground with ever-finer abrasives, removing the surplus binder until the chips are flush, then polished to a mirror and grouted where needed. Cementitious and porous, it must be treated and protected against stains and acids. It is slow and handcrafted, but lasts for generations and can always be re-ground.
Why it works
Chips in a binder, ground to a mirrorA terrazzo is not laid, it is made: marble and stone chips are sown into a binder paste, compacted and left to harden into a single artificial stone. Freshly cast it is unpromising — dull, the binder smearing over and hiding the chips. The whole beauty appears in the finishing: the hardened surface is ground down with ever-finer abrasives, cutting away the surplus binder until the chips are sliced flush and revealed, then polished until they shine like a fused mosaic. Two craftsman’s tricks make it last. Brass strips, embedded into fields, give the rigid cement surface somewhere planned to move, so it cracks along the design lines and not at random — joint and pattern in one. And because it is cementitious and porous, it is sealed against stains and acids. Slow and handmade, a terrazzo wears for generations and, like stone, can always be ground back to new.
Lifespan and restorability
Comparison · insulantsNodal details
Critical junctions · sectionsOn the screed the seminato is cast: stone chips sown into a binder, a few centimetres thick, divided into fields by brass strips. Once hard it is ground to slice the chips flush and polished to a mirror. The surface you walk on is a thin polished skin of a single artificial stone.
- Polished surface
- Stone chip
- Binder
- Brass strip
- Screed
- Structural slab
A continuous, rigid cement floor must be told where to crack: a brass strip, set on edge into the cast and finished flush with the surface, divides it into fields. It is joint and pattern at once — the floor moves and cracks along the designed lines, not at random.
- Field A (terrazzo)
- Field B (terrazzo)
- Brass strip
- Polished surface
- Binder
- Screed
Installation controls
Specification · checklist01 · Substrate
02 · Joints & layout
03 · Casting
04 · Grinding & polish
05 · Protection
Recurring defects
Diagnostics · siteComponent materials
The network · materialsReference regulations
2 norms- D.P.R. 380/2001Consolidated Building Act (Testo Unico Edilizia)In force
- UNI EN 13501-1:2019Fire classification of construction products and building elements - Part 1: Reaction to fireIn force
Informational links to the regulatory framework. Always verify the current text on the official source.