Stone, composed anew.
Made to endure.
A practical guide to choosing, ordering, installing and caring for cement-based terrazzo — a mineral surface made from natural stone aggregate, cement and pigments.
The selected finish and protective treatment affect appearance, slip performance and maintenance.
What is terrazzo?
Terrazzo is a composite mineral surface in which natural-stone and, in selected designs, glass aggregates are set within a coloured cementitious matrix and finished to reveal the pattern.
The distribution of stone fragments never repeats literally. Even within one production batch, every piece has its own balance of aggregate, tone and pattern density. Across a larger area, the individual tiles combine into one continuous surface.
Cement-based terrazzo behaves like other mineral and natural-stone surfaces: it is sensitive to acids, requires a correctly selected protective treatment and develops a patina through use.
This guide covers cement-based terrazzo supplied as tiles and individual architectural elements. Resin and epoxy terrazzo systems have a different composition and require separate manufacturer guidance.
A pattern made of stone
Aggregate size, colour and density establish the rhythm and visual scale of the surface.
Mineral depth
Colour and aggregate continue through the working body rather than being printed only on the face.
A renewable surface
Subject to product thickness and condition, terrazzo can often be professionally honed, repaired and resealed.
How it is made
Exact formulations and production methods vary, but cement-based terrazzo follows a sequence of composition, forming, curing and mechanical finishing.
Binder composition, percentage of natural stone, forming pressure, curing period, finish and any factory protection are product-specific and must be confirmed in the current SERA technical documentation.
Aggregates and finishes
The visual character of terrazzo is set by the aggregate; the finish determines how strongly that pattern is revealed and how the surface performs.
| Element | Character | What to consider |
|---|---|---|
| Fine aggregate | Calm, even grain that reads as a continuous field. | Well suited to restrained interiors and smaller areas. |
| Medium aggregate | A clear balance between the coloured base and visible stone. | The pattern reads both close up and from a distance. |
| Large aggregate | Expressive fragments and a strong architectural scale. | Cuts, edges and the position of joints become more visible. |
| Mixed aggregate | Irregular, layered distribution of different stone fractions. | Blend all boxes and approve a complete dry layout. |
| Honed finish | Smooth, matt or softly reflective. | A versatile interior finish; wet-floor use still requires tested slip performance. |
| Polished finish | Glossy, with deeper colour and strongly revealed stone. | Generally avoided on wet or exterior floors unless specifically assessed. |
| Brushed finish | Soft texture with little or no sheen. | Provides more tactile character but may retain more dirt. |
| Bush-hammered finish | Pronounced, evenly textured relief. | May suit exterior or high-traction areas when the specific product is approved. |
Natural characteristics
Terrazzo is composed through variation rather than manufactured as a perfectly identical surface.
Colour and batch
The tone of the cement base and stone aggregate can vary within one batch and between batches.
Aggregate distribution
Fragments differ in position, scale and density; two identical tiles are not possible.
Pores and depressions
Small open pores, grains and local depressions may remain visible after finishing.
Veins and fine lines
Natural veining, minor crazing and fine surface lines may not affect material integrity.
Edges and geometry
Minor dimensional variation, bevels, local chips and thickness differences require adjustment during installation.
Moisture and clouding
Condensation during transport can temporarily darken the matrix. Assess colour only after complete drying.
Transport traces
Dust, protective wax, contact strips or light rubbing must be removed only by an approved method.
Patina
Sheen and tone gradually change through traffic, water, cleaning and light.
Fine scratches
Marks are more visible on smooth finishes, although some can be professionally reduced.
Formats and construction
Terrazzo is supplied as tiles, large formats, slabs and bespoke architectural elements. Thickness, weight, handling and substrate loading must be planned before ordering.
Supply forms
| Form | Typical possibilities | What to confirm |
|---|---|---|
| Tile | Floors, walls, splashbacks, steps and modular layouts. | Format, thickness, weight, joint, tolerances and coverage per square metre. |
| Large-format tile | Fewer joints and a calmer, more continuous surface. | Substrate capacity, lifting, full adhesive contact and deformation stresses. |
| Slab | Worktops, panels, furniture, cladding and custom details. | Fabrication, support, reinforcement around cut-outs and transport. |
| Steps and risers | Monolithic or assembled stair components. | Slip-resistant profile, nosing, visible edge and design loads. |
| Skirtings and details | Floor terminations, upstands, shelves and reveals. | Bevel, edge polishing, pattern alignment and fixing method. |
What the product data must define
| Information | Why it matters |
|---|---|
| Nominal dimensions and tolerances | Set-out, joint width, alignment and finished transitions. |
| Thickness and weight | Substrate loading, adhesive depth, wall fixing and handling. |
| Finish and edge profile | Appearance, slip performance, joint expression and exposed details. |
| Pieces and area per box | Quantity calculation, reserve and transport planning. |
| Permitted fabrication | Cut-outs, mitres, edge polishing, drilling and slab reinforcement. |
Where can it be used?
Suitability depends on finish, format, traffic, substrate, waterproofing, climate, final protection, slip requirements and the complete installation system.
| Application | Status | Key condition |
|---|---|---|
| Interior walls and backsplashes | Suitable | Stable substrate, compatible adhesive and correct protection. |
| Dry residential floors | Suitable | Full adhesive support, approved finish and protection from abrasive dirt. |
| High-use residential floors | Conditional | Confirm abrasion, impact loads, footwear and maintenance regime. |
| Commercial floors | Project review | Confirm traffic, slip performance after sealing, cleaning and repair strategy. |
| Shower walls | Conditional | Complete waterproofing and sealing of tile and joints. |
| Shower floors / wet rooms | Project review | Falls, drainage, format, joint density and tested slip performance. |
| Steam showers | Not standard | Use only with a high-vapour membrane and written product approval. |
| Pools / fountains / immersion | Not standard | Do not use without specific written approval for continuous immersion. |
| Exterior walls | Project review | Confirm fixing, drainage, UV stability and freeze-thaw performance. |
| Exterior floors | Project review | Textured finish, drainage, installation temperature and confirmed testing. |
| Underfloor heating | Conditional | Flexible system, movement joints, anti-fracture strategy and gradual commissioning. |
| Fireplace surround / hearth | Conditional | Decorative area outside direct flame and excessive heat. |
| Worktops / counters | Project review | Acid behaviour, food contact, cut-outs, support, heat and professional fabrication. |
| Steps | Project review | Slip-resistant finish, nosing, visible edge and structural loading. |
| Vehicle traffic | Not standard | Do not use without a separately engineered and certified system. |
This matrix is a specification starting point, not project approval. Product-specific technical data, local regulations and professional advice take precedence.
Before you order
Plan each continuous surface as one production batch. An add-on order may differ in base colour, aggregate, finish, thickness and absorption.
- Approve samples as a reference for the colour family, aggregate scale and finish, not as a guarantee of identical pieces.
- Order the full quantity and retained repair stock at the same time.
- Prepare a layout showing axes, aggregate direction, movement joints, cuts and exposed edges.
- For wet, exterior and commercial areas, obtain written confirmation for the exact product.
- Confirm nominal dimensions, thickness, weight, pieces per box and coverage per box.
- Agree the substrate, membrane, adhesive, joint, grout, pre-treatment, sealer and cleaner before work begins.
- Confirm that the installer and any slab fabricator have experience with terrazzo or natural stone.
Receiving, storage and inspection
Inspect, dry and organise the complete order before committing any piece to the substrate.
Photograph packaging, count boxes and record visible damage before signing where possible.
Check collection, colour, finish, format, thickness and the overall range of aggregate.
If pieces appear darker, patchy, cool or damp, allow them to dry fully before judging colour.
Remove damp pieces from packaging and place them in a protected, ventilated area. Do not stack damp terrazzo.
Remove wax, spacers or contact strips only with plastic tools or another approved method.
Distribute tone, aggregate scale and natural characteristics across the complete installation.
Check pattern balance, direction, joints, cuts, transitions and exposed edges.
Test grout, sealer, cleaner, sheen and final appearance in the actual project light.
Installation principles
The finished result depends on substrate stability, moisture control, full adhesive contact, alignment and protection throughout construction.
It must be sound, stable, fully cured, dry, level and free from dust, oil, paint and weak layers.
Moisture from an uncured screed or below the assembly can cause mottling, efflorescence and sealer problems.
In wet areas, water is controlled behind the terrazzo. Tile, grout and sealer are not waterproofing.
On heated or movement-prone substrates, provide the specified uncoupling or anti-fracture solution.
Do not bridge structural, perimeter or movement joints. Their location is defined by the project designer.
Fix axes, finished level, position of full pieces, cuts, thresholds and exposed edges.
Some systems require light dampening; others require a completely dry back. Follow the approved instructions.
Use the specified white or suitable flexible adhesive with a notched trowel.
Apply adhesive to the tile back and achieve full, void-free contact, especially on floors and large formats.
Press with the palm and adjust the bed. Do not use a hammer or mallet that may create microcracks.
Use wedges or shims to maintain straight joints. Significant lipping cannot be corrected after cure.
Remove adhesive from the face immediately with clean water and a soft sponge.
Use a water-cooled diamond saw. Clean and dry the cut surface immediately and control silica dust.
Do not load, wash, seal or grout until the specified curing and drying time has elapsed.
Use strong, breathable paperboard without bonding tape directly to the terrazzo.
Sealing and grouting
Why protection is essential
Cement-based terrazzo and exposed natural stone can absorb water, oil and pigments. The correct sequence reduces staining and grout haze but does not make the installation waterproof or acid-resistant.
Before grouting
- Allow adhesive, tile and joints to become completely dry.
- Test cleaner, pre-grout treatment, grout, silicone and sealer together on spare pieces.
- Apply the approved pre-sealer or grout-release treatment where required.
- Remove all excess treatment before it dries.
- Confirm colour change, sheen and slip performance after full cure.
Grouting
Use a compatible grout in a shade close to the principal tile colour unless a tested design specifies otherwise.
- Use the grouting method approved for the exact finish and collection.
- Work in small areas and remove excess before a film forms.
- Use continuously clean water and soft, non-metallic tools.
- Never remove residue with an acidic cement cleaner.
- Allow complete drying before final protection.
Final treatment
Apply the approved penetrating or topical system to the clean, dry tile and joints. Remove excess, allow full cure and complete a water-bead test where appropriate.
Project-specific conditions
Floors and commercial spaces
Confirm abrasion, impact loads, slip performance after sealing, entrance matting, maintenance frequency and retained repair stock.
Showers and wet rooms
Design the membrane, falls, drainage, joints, finish and sealing as one coordinated system.
Steam showers
High temperature and vapour require a specialist membrane and written product approval.
Pools and fountains
Do not assume that ordinary wet-area suitability includes continuous immersion.
Exterior surfaces
Confirm traction, drainage, UV stability, freeze-thaw performance and installation temperature for the exact product.
Underfloor heating
Use a compatible flexible system and controlled commissioning after full cure.
Fireplaces and hearths
Keep terrazzo outside direct flame and excessive heat and comply with local clearances.
Kitchens and splashbacks
Remove vinegar, citrus, wine, carbonated drinks, oils and coloured foods immediately.
Worktops and slabs
Use a professional stone fabricator and confirm support, cut-outs, food-contact requirements and acid behaviour.
Steps and exposed edges
Agree the finish, nosing, bevel, anti-slip treatment and visible edge before fabrication.
Care and maintenance
Care for terrazzo as a natural-stone surface: remove abrasive dirt, wipe spills promptly and maintain the protective treatment.
- Vacuum or sweep regularly to remove sand, salt and hard particles.
- Wash with warm water and a pH-neutral cleaner approved for terrazzo or natural stone.
- Wipe wine, coffee, vinegar, citrus, carbonated drinks, oil, cosmetics, paint and chemicals immediately.
- Do not use acids, limescale removers, vinegar, lemon, chlorine bleach, strong alkalis or metallic brushes.
- Do not use a general household cleaner without testing; it may rapidly break down the sealer.
- Use entrance mats that retain grit and moisture without transferring colour.
- In showers, squeegee after use and clean joints with a soft non-metallic brush.
- On exterior surfaces, remove leaves, organic contamination and standing water promptly.
- Periodically complete a water-bead test in an inconspicuous area.
- Renew protection when water- and oil-repellency declines rather than relying only on a fixed calendar.
Patina, local repair and renewal
Terrazzo changes through traffic, water, cleaning and light. This gradual shift in sheen and tone forms the material’s patina.
Depending on the product thickness and condition, a professional may reduce fine scratches, fill pores and chips, hone or polish the surface and renew the protective treatment.
Persistent marks must be diagnosed before work begins. Oil, moisture, grout residue, construction damage and acid etching require different treatments.
What to retain after installation
- Repair stock from the original batch.
- Collection name, colour, format, finish and batch reference.
- Photographs of the dry layout, mock-up and completed surface.
- Names of adhesive, grout, silicone, cleaner and sealer.
- Treatment dates and a maintenance record.
- Installer and stone-restoration specialist contact details.
Frequently asked questions
Why is the pattern different on every tile?
Stone aggregate is distributed naturally within the cement matrix. The variation is a defining characteristic of terrazzo.
Will my order match the sample?
The sample indicates the general colour family, aggregate and finish. It cannot represent every piece or guarantee a later batch match.
How much reserve should I order?
SERA recommends at least 15%. Increase the reserve for large formats, complex cutting, strict visual selection or contrasting grout.
Do I need to blend boxes?
Yes. Dry lay and distribute material from all boxes so tone and aggregate form a balanced field.
Does terrazzo need sealing?
Porous cement-based terrazzo normally requires protection before and after grouting. Follow the technical data for the exact collection.
What joint width should be used?
The final joint depends on format, tolerances, substrate, heating and application. Approve it on a mock-up.
Can I use contrasting grout?
Only after testing. Pigment can lodge in pores and fine lines, so additional reserve and suitable pre-treatment may be required.
Can terrazzo be used in a shower?
Only as part of a correctly designed wet-area system with waterproofing, falls, drainage, sealing and confirmed slip performance.
Can terrazzo be used outdoors?
Only when the exact product has suitable finish, UV and freeze-thaw performance and the exterior system is approved.
Can it be used with underfloor heating?
Usually, with a compatible flexible system, movement joints, anti-fracture strategy and controlled commissioning.
Why did lemon or vinegar leave a matt mark?
The acid etched the cement matrix or natural stone. Sealer does not provide complete acid resistance.
Can an old terrazzo surface be renewed?
Many terrazzo surfaces can be professionally honed, repaired, polished and resealed after their thickness and condition are assessed.
Documents and important information
Where the technical data sheet for a specific product differs from the general recommendations in this guide, the current product documentation takes precedence.
General guidance
This guide describes the general character and handling of cement-based terrazzo. It is not a project specification and does not replace professional advice.
The architect, designer, contractor, installer and fabricator are responsible for confirming product suitability, substrate, waterproofing, adhesive, grout, sealer, movement joints, loads, slip performance, fire requirements and compliance with local regulations.
Inspect all material before cutting and installation. Cutting or installing terrazzo confirms acceptance of its visible characteristics. Contact SERA with application questions before the first piece is installed.