How the two differ in kind
Terrazzo is aggregate — marble, granite, glass — set in a binder and then ground flat and polished. The decorative material goes all the way through, which is why a terrazzo floor can be reground several times over its life and come back looking new, and why the floors that survive in civic buildings for a century are terrazzo.
An epoxy resin floor is a coating or a thin screed bonded to the slab beneath it. It arrives fast, in any colour, with genuine chemical resistance, and it is finished when it has worn through — at which point it is prepared and recoated rather than reground. That is not a defect; it is a different economic model, and for a building with a ten-year horizon it is frequently the better one.
The constraint that decides most of these is the SLAB. An epoxy floor is bonded to it, so it inherits everything about it: its moisture content, its soundness, its contamination, its flatness. Moisture is the one that ends jobs — vapour driving up through a slab with no effective membrane collects under an impermeable coating and lifts it off in blisters, and no amount of surface preparation prevents it. A relative humidity test in the slab is a condition of every serious resin warranty, and installing without one is installing without a warranty.
The factors that actually differ
Show
| Terrazzo | Epoxy resin floor | |
|---|---|---|
| What it is | A material with the decorative aggregate through its full depth. | A coating or thin screed bonded to the slab, with its appearance in the top fraction of a millimetre. |
| Renewing it | Reground and repolished, several times over decades, back to as-new. The floor gets thinner and does not get older. | Prepared and recoated on a cycle. Each recoat is a possession of the space and a preparation operation. |
| Cracking | Controlled by DIVIDER STRIPS, which are control joints rather than pattern. They decide where the cracks go, and a panel too large without one cracks across the middle. | Follows the substrate. A crack in the slab reflects through the coating, and moving joints have to be carried up through it rather than coated over. |
| The slab beneath | Cement-based terrazzo can be bonded, unbonded or on a sand cushion, which tolerates a poorer slab. Thin-set epoxy terrazzo is as demanding as any resin. | Entirely dependent on it. Moisture, laitance, contamination and flatness all transfer, and preparation is most of the job. |
| Moisture in the slab | Cement-based systems are far more tolerant — they are permeable, so vapour passes rather than accumulating. | The characteristic failure. Vapour collects under an impermeable film and lifts it in osmotic blisters. A slab test is mandatory, and a moisture-suppressing primer is the remedy where the reading is high. |
| Programme | Slow. Placing, curing, grinding and polishing over weeks for cement-based systems; faster for epoxy-bound terrazzo, which is a hybrid. | Fast. Days rather than weeks, which is frequently the whole reason it is chosen. |
| Chemical resistance | Good for a cement-based binder; excellent for an epoxy-bound one. Neither likes strong acids, which attack the marble aggregate itself. | Excellent and specifiable. This is what puts it in laboratories, plant rooms and process areas. |
| Shape of the cost | High capital, very low whole-life. The comparison only favours it over a long horizon, and it favours it decisively there. | Lower capital and a recoating cycle. The right answer where the building's use, tenant or brand will change before the floor wears out. |
Which one, and when
Choose terrazzo when…
- The building has a long horizon and the floor is expected to outlive several fit-outs.
- Traffic is heavy and abrasive, and a surface that can be reground rather than replaced is worth its capital cost.
- The slab is marginal — a cement-based terrazzo on a sand cushion tolerates what a bonded coating will not.
- The appearance has to survive decades of wear rather than years, which a through-depth material does and a coating does not.
Choose epoxy resin floor when…
- The programme is short and the floor has to be in use within days.
- Chemical or hygiene performance is the requirement — a laboratory, a process area, a food space.
- The use will change: a tenant fit-out, a space expected to be reconfigured, a brand that will want a different colour.
- The budget is capital-constrained and the recoating cycle is acceptable.
Now run your own numbers
This page holds no prices on purpose — a national average is wrong for almost every real project. Quantify both options with your dimensions and your local quotes.
Frequently asked questions
- Why does terrazzo have metal strips in it?
- Because they are control joints, not pattern. Terrazzo is a cementitious or resinous material laid in large continuous areas, and like any such material it shrinks as it cures and moves with temperature — so it will crack, and the only question is where. A divider strip creates a deliberate weakness at a chosen line, so the crack forms there and is invisible inside the strip rather than wandering across the floor. That is why they appear at panel sizes rather than wherever the pattern would like, why they must align with any movement joint in the slab beneath, and why a large panel laid without one cracks across the middle. The decorative use of them is a second life for a structural necessity.
- Can epoxy go over a damp slab?
- Not without addressing the moisture first, and this is the single commonest cause of resin floor failure. Water vapour moving up through a slab with no effective membrane reaches the underside of an impermeable coating and cannot pass — it accumulates, and the osmotic pressure lifts the coating off in blisters, sometimes months after installation and always after the installer has left. The test is an in-situ relative humidity probe or a hygrometer box left for the specified period, and the result is compared against the resin manufacturer's limit. Where the reading is too high the routes are waiting, which may not be possible, or a moisture-suppressing epoxy primer, which is a specified product rather than an extra coat of the same thing.
- Which is more slip-resistant?
- Neither, polished, when wet — and that is the honest answer that matters more than either product's datasheet. A polished terrazzo floor and a smooth epoxy floor are both slippery with water on them, which is why entrance matting, falls to drainage and a change of surface at wet thresholds are part of the design rather than an afterthought. Both can be made slip-resistant: terrazzo by a honed rather than polished finish or by a textured aggregate, epoxy by broadcasting aggregate into the wet coat. Both reduce the ease of cleaning in proportion. The requirement should be stated as a measured value under the relevant test rather than as a preference, because the difference between finishes of the same material is larger than the difference between the materials.
- Can terrazzo be repaired?
- Yes, and better than most floors — which is a large part of its case. Local damage is cut out and re-poured with matching aggregate, and because the material is the same through its depth the repair grinds back into the surrounding floor and largely disappears. Whole-floor renewal is a regrind and repolish, which removes a fraction of a millimetre and returns the floor to as-new; a terrazzo floor can take several of those over its life. The limit is thickness, and eventually the aggregate at the surface has been ground past its best. By comparison, an epoxy floor is prepared back and recoated — which is a legitimate maintenance route, but it is replacing the finish rather than renewing the material.
- Which for a commercial kitchen?
- Usually neither as described here. A commercial kitchen wants a floor that is seamless, coved at the walls, laid to falls with drainage, resistant to hot oils and cleaning chemicals, and slip-resistant while wet and greasy — and the material that meets that specification is generally a urethane or polyurethane-cement screed rather than either of these. Epoxy is close but less tolerant of thermal shock from hot water and steam cleaning, and polished terrazzo is the wrong surface texture entirely. This is worth saying plainly because both products are marketed for the application, and the failure — a floor that debonds under steam cleaning or that people slip on — is not one anybody wants to discover in service.
- What actually drives the cost of each?
- For terrazzo, labour and programme: placing, curing, grinding and polishing are separate operations with time between them, and the grinding is skilled and slow. The aggregate itself is a real cost where the specification calls for a particular marble or a glass content, which is what the mix calculator is for. For epoxy, preparation and coverage: the substrate has to be mechanically prepared — shot-blasted or ground — and any repair, moisture mitigation or levelling happens before a drop of resin is poured, so a poor slab can cost more to prepare than the coating costs to apply. Both calculators return material quantities for the specification given; neither returns the preparation, which is where the money on a resin floor usually goes.