Terrazzo flooring is one of the most durable floor finishes there is, capable of staying in good condition for decades if it receives proper maintenance. However, over time and with daily use, it loses its original shine, and stains, surface scratches and a general look of dirt appear that regular mopping cannot remove. In this guide we explain how to polish a terrazzo floor using the professional method step by step, what the difference is between polishing, buffing and crystallising, and what home alternatives exist if you do not have specialised machinery.
What terrazzo is and why it loses its shine
Before polishing, it is worth understanding what type of terrazzo you have, because not all types behave the same way when polished:
- Continuous terrazzo (poured in place): it is poured on site as a mixture of cement, marble or granite aggregate and water, and is polished directly on the floor itself once cured. It is the most common type in industrial buildings, garages and large commercial premises.
- Terrazzo tile (mosaic or hydraulic): prefabricated pieces of standard size (usually 20×20, 30×30 or 40×40 cm) that are installed like any ceramic tile. It has visible joints between pieces, which requires more care during polishing so as not to let abrasive or moisture build up in them.
In both cases, the material combines a matrix (cement or resin) with marble, granite or glass aggregates, and it is precisely this matrix that determines how it reacts to cleaning products: cement is alkaline and porous, whereas epoxy resin is more resistant to chemicals but can be scratched more easily. The shine is lost through a combination of factors: abrasion from daily foot traffic, micropores that trap grease and dirt, the use of unsuitable cleaning products that attack the matrix, and the gradual loss of the factory-polished surface layer.
Tools and materials for professional terrazzo polishing
Professional terrazzo polishing requires specific equipment, very different from that used for simple maintenance cleaning:
- Single-disc or planetary polisher: single-disc machines are more common on small or uneven surfaces; planetary machines, with several disc heads that rotate independently, give a more uniform finish on large surfaces and are the standard in professional work.
- Diamond discs: the actual abrasive element. They come in two main types: metal-bond (more aggressive, for the first grinding stages) and resin-bond (softer, for the finishing and shine stages).
- Water system or dry dust extraction: wet polishing reduces dust generation and cools the disc, but produces slurry that has to be removed; dry polishing requires a dust extractor connected to the machine so as not to disperse silica particles into the air.
- Wool pad or disc: used in the final buffing stage, after diamond polishing, to spread the crystalliser or polish evenly.
How to polish a terrazzo floor step by step
Professional polishing follows a grit progression from coarser to finer. Each disc removes the marks left by the previous one, so skipping intermediate steps is one of the most common mistakes among those new to this work.
| Stage | Disc grit | Purpose |
|---|---|---|
| Initial grinding | Metal 30-50 | Level the surface and remove deep scratches |
| Intermediate grinding | Metal 100-200 | Refine the marks left by the previous grit |
| Fine polishing | Resin 400-800 | Start building surface shine |
| Glossy finish | Resin 1500-3000 | Final shine before crystallising |
Surface preparation
Before the first pass of the disc, the surface must be completely free of grease, old wax and ingrained dirt. Any greasy residue gets into the pores of the diamond disc and acts as an uncontrolled abrasive, producing irregular marks instead of a uniform surface. In high-traffic premises —shops, industrial buildings, catering areas— this stage usually requires a professional alkaline degreaser, since conventional mopping does not remove the grease built up in the micropores of the material.
Diamond polishing, from coarse to fine grit
Start with the coarsest metal-bond disc indicated in the table above and progress gradually towards the finer resin grits. Each stage must cover 100% of the surface before moving on to the next, and between discs it is advisable to remove the slurry or dust generated so as not to carry coarse grit into the fine stage, which would leave visible marks in the finish.
Crystallising and final buffing
This final step is the one most often confused, and it deserves a separate explanation.
The difference between polishing, buffing and crystallising terrazzo
These are three different processes that are often used as synonyms, but they are not:
- Polishing is a mechanical process: the surface is worn down with abrasive discs of progressive grit until it is levelled and given shine through physical friction.
- Buffing consists of applying a product (wax or liquid polish) that deposits a glossy surface layer on the material, without chemically modifying the stone. This layer wears away with use and needs to be reapplied periodically.
- Crystallising is a chemical process: a fluorosilicate-based product is applied that reacts with the calcium carbonate of the marble present in the terrazzo, forming calcium fluorosilicate, a compound that hardens and vitrifies the surface layer of the stone. Unlike wax, crystallisation is not an added layer but a transformation of the surface of the material itself, which gives it greater durability against wear.
In a complete professional process, the usual approach is to polish mechanically with diamond down to the finest grit and then crystallise to maximise hardness and final shine. Wax buffing is reserved for maintenance between crystallisations, or as a cheaper alternative when polishing machinery is not available.
How to polish a terrazzo floor at home
If you do not have professional machinery or crystallising products, there are home methods that can restore some of the terrazzo’s shine, although with more limited results than mechanical diamond polishing:
- Thorough prior cleaning: scrub the floor with hot water and a neutral degreaser, paying extra attention to the busiest areas. Do not use bleach or acidic products, as they can damage the marble or granite in the terrazzo.
- Manual polishing with baking soda: mix baking soda with a little water to form a paste, apply it to the dull areas and rub with a microfibre cloth or a low-power household rotary machine. Baking soda acts as a very mild abrasive without scratching the surface, although its effect is considerably weaker than that of a diamond disc.
- Applying household wax or polish: after cleaning and manual polishing, apply a wax specific for stone floors or a liquid polish, spreading it in thin coats and allowing it to dry between applications.
- Polishing with a cloth and rotary machine: if you have a low-speed household polisher, a wool pad fitted to the machine can help spread the polish evenly and enhance the final shine.
The result of home polishing will not be identical to that of professional polishing with a diamond progression and chemical crystallisation, but it is a valid option for maintenance between professional polishes or for small surfaces.
How to treat specific stains before polishing
Not every stain is removed in the same way, and treating it incorrectly before polishing can fix it permanently in the stone:
- Grease and oil stains: they require an alkaline degreaser with sufficient contact time to penetrate the pore. Subsequent polishing does not remove grease that has penetrated deeply if it has not been treated beforehand.
- Rust stains: they come from metal objects in prolonged contact with the moisture of the terrazzo. They require specific rust-removing products, since a conventional degreaser does not remove them.
- Damp stains or whitish rings: they usually indicate that water has seeped in and reacted with the salts in the cement. Before polishing, make sure the underlying moisture has been resolved, or the stain will reappear after polishing.
Common mistakes when polishing terrazzo
- Using bleach or acidic products: they can attack the marble and granite in the terrazzo, leaving irreversible dull stains.
- Polishing without removing grease first: greasy dirt acts as an uncontrolled abrasive and can produce irregular marks during mechanical polishing.
- Skipping intermediate grit steps: going straight from a very coarse grit to a very fine one leaves marks from the previous stage visible under the final shine.
- Confusing buffing with crystallising: applying only wax while expecting the durability of crystallisation leads to disappointment, since wax wears away much sooner.
- Not resolving the cause of a stain before polishing: polishing over an active damp leak or an untreated rust stain makes it reappear shortly afterwards.
When a professional degreaser is advisable before polishing
In commercial or industrial premises, the grease built up in terrazzo is usually much more resistant than at home, especially in kitchen areas, workshops or production areas. Before any professional polishing, it is essential to start from a completely degreased surface. If you want to know which type of degreaser is most suitable depending on the level of dirt and the surface, we have explained it in detail in our guide to types of industrial degreasers and how to choose the most suitable one.
At CH Química we specialise in chemical products for industrial and institutional hygiene. Contact us if you need advice on which degreaser to use before polishing the terrazzo in your premises.
Frequently asked questions about how to polish a terrazzo floor
Can terrazzo be polished without professional machinery?
Yes, it is possible to restore some of the shine with home methods such as baking soda as a mild abrasive and the application of wax or polish for stone floors. However, the result will not be as uniform or long-lasting as that of professional polishing with a progression of diamond discs, which does manage to remove deeper scratches and prepare the surface for crystallising.
What is the difference between polishing, buffing and crystallising terrazzo?
Polishing is a mechanical process that wears down the surface with progressive abrasive discs. Buffing consists of applying a layer of wax or a product that adds shine without modifying the stone, and that wears away with use. Crystallising is a chemical process that reacts with the calcium carbonate of the marble, forming a hardened, vitrified layer that is much more durable than wax, but that requires the surface to have been polished beforehand.
How often does a terrazzo floor need to be polished?
In a home with moderate foot traffic, professional polishing every 3 to 5 years is usually enough, complemented by occasional home maintenance. In commercial or industrial premises with heavy traffic, professional polishing may be necessary every 12 to 24 months, depending on the volume of use and the type of dirt the floor is exposed to.
Which products should not be used to clean terrazzo?
Avoid bleach, acidic products and cleaners with highly concentrated vinegar, since they chemically attack the marble and granite in the terrazzo, causing dull stains and permanently damaging the shine. It is also advisable to avoid very abrasive scourers or fibre discs that could scratch the surface.
Why is it important to degrease terrazzo before polishing it?
Grease built up in the pores of the terrazzo gets into the diamond disc itself during polishing and acts as an uncontrolled abrasive, producing irregular marks on the surface. Starting from a completely degreased floor ensures that the disc works uniformly and that the final result is consistent across the entire floor.
How long does the shine last after polishing and crystallising terrazzo?
Properly polished and crystallised terrazzo can keep a good level of shine for 1 to 3 years in domestic use, and between 6 and 12 months in high-traffic commercial or industrial environments, provided it is maintained with suitable cleaning products that do not attack the crystallised layer. Wax buffing alone, without chemical crystallisation, lasts much less, usually a few weeks to a few months.