Terrazzo Flooring: In-Situ Cement, Epoxy and Precast Tile Compared

Terrazzo is a floor of marble or other chips set in a binder, ground flat and polished. In-situ cement terrazzo is laid wet in bays between divider strips; epoxy terrazzo uses a thin resin binder with more colour freedom and fewer cracks; precast terrazzo tiles are factory-made and laid like other cement tiles. All three are durable, but cracks follow joints in the slab beneath.

By Dhruv Agarwal · · 4 min read

What the terrazzo decision turns on

Terrazzo is chips of marble, granite, glass or other aggregate set in a binder, then ground flat and polished so the aggregate shows through. It is specified for lobbies, airports, hospitals, schools and transit buildings because a well-laid terrazzo floor lasts for decades, takes heavy wheel and foot traffic, and can be reground rather than replaced.

The decision is less "terrazzo or not" than which kind: in-situ cement, epoxy (resin) or precast tile. They look alike in a sample board and behave very differently on site. The cost of choosing badly is cracks that follow the slab joints across a feature lobby, a heavy floor on a slab that was not designed for it, or a resin floor laid on a damp slab that debonds. The common misconception is that terrazzo cracks because it is "old-fashioned". It usually cracks because of what is under it.

The three types compared

In-situ cement terrazzoEpoxy terrazzoPrecast terrazzo tiles
BinderCement, often with pigmentEpoxy resinCement, factory-cured
Thickness and weightThick and heavy, laid over an underlayerTypically a thin layer, much lighterTile plus bed; moderate
Colour and patternModerate range, pattern set by stripsWide range, fine detail and inlaysSet by the tile range
Cracking tendencyShrinkage and reflective cracks if poorly detailedLower, but follows slab movementJoints between tiles absorb some movement
Slab moisture sensitivityTolerantNeeds a dry, tested slabTolerant
Site disruptionHigh: wet laying, curing, multiple grindsModerate: resin work, grindingModerate: laying, then grinding
ReferenceIS 2114Manufacturer's system dataIS 1237, IS 1443, EN 13748-1

Exact thicknesses depend on the system and are set by the manufacturer's data and the project engineer, particularly where the added load on an existing slab matters.

How in-situ terrazzo is laid

The Indian code of practice for in-situ terrazzo is IS 2114. In outline, the work follows a sequence:

  1. Underlayer of cement concrete or mortar over the prepared base
  2. Divider strips of glass, brass, aluminium or plastic set out in bays
  3. Topping of chips, cement and pigment laid in each bay and compacted
  4. Curing, kept damp so the topping does not dry and shrink too fast
  5. Grinding in stages, coarse to fine, with grouting of pinholes between grinds
  6. Polishing and, where specified, sealing

Each step needs time. Terrazzo is one of the few finishes where several weeks of wet work sit on the critical path of a lobby, so the programme should show it honestly.

Divider strips and cracking

Divider strips do two jobs: they form the pattern, and they break the floor into bays so shrinkage and movement are taken at the strip rather than as random cracks. They only work if they line up with the joints in the slab beneath. A slab joint that runs across the middle of a bay will crack through the terrazzo, however good the topping.

Where the building has movement joints, the terrazzo needs a true movement joint at the same line, not just a decorative strip. Epoxy terrazzo reduces shrinkage cracking but still reflects cracks and movement in the slab, which is why its manufacturers usually ask for crack treatment and joint detailing before the resin goes down.

Terrazzo tiles

Precast terrazzo tiles are covered by IS 1237, the specification for cement concrete flooring tiles, which includes terrazzo tiles, with laying and finishing practice in IS 1443. The European product standard for internal terrazzo tiles is EN 13748-1. Tiles are often ground and polished after laying to remove lipping, which gives a near-continuous surface with less wet work than in-situ terrazzo.

Terrazzo against other hard floors

Against epoxy flooring, terrazzo is decorative and long-lived while plain epoxy coatings are utilitarian and need recoating. Against Kota stone and vitrified tile, terrazzo gives design freedom with very few joints, at the cost of more site time. For hospital floors in particular, see the requirements set out for hospital and healthcare buildings.

Common mistakes

  • Divider strips that ignore the slab joints. The crack appears along the slab joint, not the strip.
  • Epoxy terrazzo on an untested slab. Moisture beneath the resin causes blisters and debonding.
  • Bays too large or cured too fast. Cement terrazzo shrinks and cracks.
  • Load not checked. Heavy cement terrazzo added to an existing floor without the engineer confirming the slab can carry it.
  • High polish at entrances. Slippery when wet; use matting and a suitable finish.
  • Acidic cleaners. Marble chips etch and the surface dulls.

What to ask your contractor or specialist

  • Which type, what total thickness, and what does it weigh per area?
  • How do divider strips and movement joints relate to the slab joints?
  • How will slab moisture be tested before resin work?
  • How many grinding stages, and what curing period, are in the programme?
  • What sealer and cleaning regime are proposed?

Standards referenced

In-situ terrazzo under IS 2114; cement concrete flooring tiles including terrazzo under IS 1237, with laying and finishing under IS 1443; internal terrazzo tiles under EN 13748-1. Thickness, added load on the slab, joint layout and slip performance for a specific floor must be confirmed by the project's structural engineer, designer and the terrazzo specialist.

Standards referenced

  • IS 2114 — Code of practice for laying in-situ terrazzo floor finish (Bureau of Indian Standards)
  • IS 1237 — Cement concrete flooring tiles — specification (includes terrazzo tiles) (Bureau of Indian Standards)
  • IS 1443 — Laying and finishing of cement concrete flooring tiles — code of practice (Bureau of Indian Standards)
  • EN 13748-1 — Terrazzo tiles — terrazzo tiles for internal use (CEN-CENELEC)

Frequently asked

Neither is better everywhere. Epoxy terrazzo is thinner and lighter, offers brighter colours and finer detail, and is less prone to shrinkage cracking, but it costs more and needs a dry, well-prepared slab. Cement terrazzo is thicker and heavier, more tolerant of site conditions and cheaper, but it cracks more readily and its colour range is narrower. The choice follows from load on the slab, design intent and how dry the slab will be when the floor goes down.

They look similar once ground, but they behave differently. Tiles are made and cured in a factory, then laid on a bed and usually ground and polished after laying, so they avoid much of the shrinkage of a large wet-laid bay. In-situ terrazzo is mixed and laid on site in bays, giving larger continuous areas and freer patterns. Tiles are covered by IS 1237 and laid under IS 1443; in-situ work is covered by IS 2114.

Most cracks in terrazzo reflect something below it: a joint or crack in the slab, a change of base material, or a bay that was too large and shrank. Cement terrazzo also cracks if it dries too quickly. Divider strips and movement joints must line up with the joints in the structure, and bay sizes should follow the laying code and the specialist's advice.

It is widely used in both because it is hard-wearing, has few joints, takes trolley and wheel traffic, and can be cleaned with ordinary floor machines. For clinical areas, the cleaning chemicals, the treatment of joints and skirting junctions, and slip resistance should be agreed with the infection-control and facilities teams before specification.

A highly polished terrazzo floor can be slippery when wet or contaminated. Slip resistance depends on the binder, the aggregate, the degree of polish and the sealer, so it is a property of the finished floor, not of terrazzo in general. Entrances need matting and, where water is expected, a less glossy finish or a tested anti-slip treatment.

Often yes. Because the chips run through the wearing layer, a worn or dull terrazzo floor can be reground, cracks filled, and the surface repolished and resealed. Whether restoration is worthwhile depends on how much wearing layer remains, the extent of cracking, and whether the base beneath is sound.

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