Tile Thickness: 6, 9, 10 or 20 mm? Which Thickness Is Right for Floors, Bathrooms and Terraces?
When choosing new tiles, most homeowners first compare colours, formats and finishes. However, an important technical question soon arises: How thick should porcelain tiles actually be?
Are 6 mm porcelain tiles suitable for floors? Are 9 or 10 mm tiles better for living areas? And why are so many outdoor porcelain slabs 20 mm thick?
Tile thickness affects weight, installation height, handling and, depending on the construction, mechanical performance. However, thickness alone does not determine whether a tile is suitable for a particular application.
Material properties, tile size, technical specifications, the substrate and the installation system are equally important.
This guide explains the differences between thin porcelain slabs, conventional floor tiles and 2 cm outdoor paving slabs, with real product examples from VITALE TILES.
What Tile Thicknesses Are Available?
Common examples include 6 mm for certain large-format porcelain slabs, approximately 8 to 10 mm for many conventional floor tiles, 12 mm for selected architectural collections and 20 mm for purpose-designed outdoor paving slabs.
These values are only a general guide. Many intermediate thicknesses exist, and each product has its own technical specifications.
A 6 mm porcelain tile may be approved for certain floor applications, while another thin ceramic product may be intended exclusively for walls.
The important question is not simply how thick the tile is, but whether the specific product is approved for the intended use.
6 mm Porcelain Tiles: Thin Slabs with Special Installation Requirements
Six-millimetre porcelain stoneware is particularly interesting for large-format applications.
Reduced thickness can make large slabs lighter than thicker alternatives of the same size.
This may be beneficial for wall coverings and certain renovation projects.
The same collection also includes Coretech Brushed Light 120 × 280 cm, also measuring 6 mm in thickness.
Such formats create generous surfaces with relatively few joints.
However, thinner does not automatically mean easier to install.
Large, thin porcelain slabs require careful handling during transportation, cutting and installation. Suitable equipment, a sufficiently flat and stable substrate, and an approved adhesive and installation system are essential.
Whether a particular 6 mm tile can be installed on a floor depends on the manufacturer's approval and the intended application.
For large, thin slabs, we recommend working with an experienced tile installer.
9 mm Tiles: A Versatile Choice for Residential Floors
Depending on their technical characteristics, these tiles are frequently used in bathrooms, kitchens, living rooms and entrance areas.
One example is Italgraniti Nuances Tortora, a rectified, matt porcelain tile available in several formats and with an R10 A+B slip resistance classification.
At 9 mm thick, it represents a typical interior floor tile.
For residential flooring, however, thickness is only one aspect of installation planning.
The substrate must have adequate load-bearing capacity and flatness. Adhesive selection, joint design and existing movement joints are equally important.
When renovating, remember that the total floor build-up is greater than the tile thickness alone.
A 9 mm tile installed with adhesive and additional levelling or waterproofing layers may result in a substantially greater overall floor height.
10 mm Tiles: Are They Better Than 9 mm Tiles?
Ten-millimetre porcelain tiles are common in numerous collections, including smaller decorative formats.
However, a 10 mm tile is not automatically better than a 9 mm tile.
A suitable example is Marazzi D-Segni Blend Azzurro, a decorative 10 × 10 cm tile.
According to the product specifications in the VITALE TILES shop, this tile is 10 mm thick, matt and non-rectified.
It illustrates why tile size and tile thickness should not be confused.
Even relatively small decorative tiles may have a substantial thickness.
When selecting tiles for kitchens, bathrooms or entrance areas, it is more important to consider approved applications, mechanical performance, slip resistance and the suitability of the surface.
12 mm Porcelain Tiles: For Specific Architectural Applications
In addition to the common 6 to 10 mm range, some porcelain collections include 12 mm slabs.
These products can be interesting for particular architectural applications and large-format projects.
For example, Gigacer Concrete Grey 12MM in 120 × 120 cm has a stated thickness of 12 mm.
Its matt concrete-inspired finish suits contemporary interiors and minimalist architecture.
Compared with thinner alternatives made from similar materials, additional thickness generally increases weight and installation height.
During renovations, this may influence floor transitions, door clearances, transport requirements and structural considerations.
For commercial environments, workshops and other demanding applications, product suitability must be determined from the actual technical data rather than thickness alone.
20 mm Outdoor Porcelain Slabs: Why Are Terrace Tiles So Thick?
Outdoor surfaces face very different conditions from indoor residential floors.
Terrace and garden slabs are exposed to rainfall, temperature changes and, in many locations, frost.
Slip resistance, drainage, substrate construction and load requirements must also be considered.
A concrete example is Italgraniti Origins Beige 2CM Antislip in 60 × 120 cm, which has a thickness of 20 mm and an R11 A+B+C classification.
Depending on manufacturer approval and the particular construction, suitable 20 mm slabs may be installed on pedestal systems, in an appropriate gravel or chippings bed, or in bonded installations.
Not every slab and format is approved for every installation method.
Raised surfaces, exposed edges, steps and locations with higher loads require particularly careful planning.
Important: A 20 mm porcelain slab is not automatically suitable for vehicle traffic or unsupported installation.
Where vehicles, high point loads or elevated safety requirements are involved, an explicitly approved construction is necessary.
How Much Do Porcelain Tiles Weigh per Square Metre?
Tile thickness has a direct influence on transportation and handling.
The following examples are based on actual product and packaging information from the VITALE TILES range.
ProductThicknessFormatApproximate weight per m²
Italgraniti Nuances Tortora | 9 mm | 60 × 120 cm | 20.2 kg
Italgraniti Origins Beige 2CM Antislip | 20 mm | 60 × 120 cm | 42.2 kg
Marazzi D-Segni Blend Azzurro | 10 mm | 10 × 10 cm | 20.1 kg
Florim Coretech Brushed Light | 6 mm | 120 × 120 cm | 14.5 kg
Gigacer Concrete Grey 12MM | 12 mm | 120 × 120 cm | 28.0 kg
Italgraniti Nuances Tortora | 9 mm | 60 × 120 cm | 20.2 kg
Italgraniti Origins Beige 2CM Antislip | 20 mm | 60 × 120 cm | 42.2 kg
Marazzi D-Segni Blend Azzurro | 10 mm | 10 × 10 cm | 20.1 kg
Florim Coretech Brushed Light | 6 mm | 120 × 120 cm | 14.5 kg
Gigacer Concrete Grey 12MM | 12 mm | 120 × 120 cm | 28.0 kg
These are specific product examples, not universal weights for every tile of the same thickness.
Consider an order of 30 m² of the 20 mm Italgraniti Origins slab. At approximately 42.2 kg/m², the tiles alone would weigh roughly 1,265 kg.
Pallets, protective packaging and other materials add further weight.
The actual order quantity must also be rounded up to complete packages.
This is one reason why larger tile deliveries are normally transported on pallets rather than as ordinary parcels.
Are Thicker Tiles Automatically Stronger?
Tile thickness influences mechanical performance, but it is not the only relevant factor.
Material composition, manufacturing methods, tile format, tested strength and installation conditions all play important roles.
A fully bonded porcelain tile behaves differently from a slab supported at only a few points.
A thin, large-format tile can fail if the substrate is inadequately prepared.
Conversely, a 20 mm outdoor slab must not be installed on arbitrary supports or used under vehicle loads without the necessary approval.
Important technical considerations include breaking load, modulus of rupture, intended application, slip resistance and the installation system.
Test methods for ceramic tile bending strength and breaking load are described in ISO 10545-4.
The correct question is therefore not simply, "How thick is this tile?" but "Is this exact tile suitable for the planned installation and use?"
Tile Thickness During Renovation: Calculating Floor Build-Up Height
When renovating a bathroom or kitchen, the available construction height may be limited.
Doors, thresholds, stairs, skirting boards and transitions to other floor coverings must still function correctly.
A simple calculation illustrates the issue.
A 9 mm porcelain tile combined with a hypothetical installed adhesive layer of 4 mm produces an initial build-up of 13 mm.
A 6 mm tile with the same hypothetical adhesive thickness would produce 10 mm.
However, the 4 mm adhesive thickness is only an example, not a general installation recommendation.
Additional layers for levelling, waterproofing or decoupling must also be considered.
More importantly, two different tile products cannot automatically be installed using the same adhesive thickness or substrate preparation.
Thin large-format slabs may require particularly demanding installation conditions.
The entire floor construction must therefore be planned before choosing a tile based on thickness alone.
Which Tile Thickness Is Suitable for Bathrooms?
There is no single ideal tile thickness for every bathroom.
Wall tiles and floor tiles are subject to different requirements.
For bathroom floors, properly approved porcelain tiles in conventional interior thicknesses are often suitable.
Some thinner large-format tiles may also be appropriate, depending on manufacturer approval.
However, the suitability for flooring, slip resistance and the complete waterproofing system are more important than the thickness alone.
Walk-in showers require additional planning.
The floor gradient and drainage layout may influence which tile formats can be used.
For example, a large-format tile may be difficult to install around a central point drain, whereas a linear drain may allow other arrangements.
Such details must be agreed with the installer before ordering.
Which Tile Thickness Is Best for Kitchens, Living Rooms and Entrances?
The thickest tile is not necessarily the best option for an ordinary residential interior.
A suitable 9 or 10 mm porcelain tile can perform well in many private spaces if the technical specifications and installation are appropriate.
Kitchens require easy-to-clean surfaces and resistance to daily wear.
Living rooms place greater emphasis on appearance, format and compatibility with underfloor heating.
Entrance areas require consideration of moisture, dirt and slip resistance.
For a spacious appearance, you can compare the characteristics of Italgraniti Nuances Tortora at 9 mm with Florim Coretech Brushed Light at 6 mm.
These are different products with different formats and installation requirements, not interchangeable technical alternatives.
Matching Indoor and Outdoor Designs Without Using the Same Thickness
Creating a visually continuous floor from the living room to the terrace is an attractive design concept.
However, the indoor and outdoor tiles do not necessarily need to be the same thickness.
Some collections include coordinated colours and finishes in different constructions.
An appropriate conventional porcelain tile can be used indoors while an approved 20 mm slab is installed outdoors.
Italgraniti Origins Beige is an example of a collection worth comparing for coordinated applications.
Before ordering, check the exact product variant, dimensions, surface finish and colour consistency.
Indoor and outdoor technical requirements remain different, even when the appearance is similar.
Order Samples and Compare Tile Thicknesses at Home
Online photographs show colours and surface finishes, but they cannot fully communicate the weight, edge detail and physical thickness of a tile.
A real sample provides a much better impression of the material.
When comparing two different thicknesses, pay attention to the edge, surface texture and overall feel.
Samples can also help evaluate colours under daylight and artificial lighting.
However, a physical sample cannot replace the technical data sheet or a professional assessment of the planned construction.
Frequently Asked Questions About Tile Thickness
How thick should floor tiles be?
There is no universally correct thickness. Many residential porcelain floor tiles are approximately 8 to 10 mm thick. Thinner and thicker products can also be suitable when approved for the intended application.
Can 6 mm porcelain tiles be installed on floors?
Some can. The manufacturer's approval and installation requirements are decisive. Thin large-format slabs often need particularly careful substrate preparation and handling.
Are 10 mm tiles better than 9 mm tiles?
Not necessarily. Thickness alone is not an indicator of quality. Technical performance, intended application and correct installation matter more.
Do bathroom tiles have to be 10 mm thick?
No. There is no universal requirement for a particular thickness. Suitable products must be selected for the walls, floor and wet areas.
Why are outdoor porcelain slabs often 20 mm thick?
Many 20 mm slabs are designed for specific outdoor applications and installation systems. Their suitability still depends on the product, substrate and loads.
How much do 20 mm porcelain slabs weigh?
Weight varies by product. Italgraniti Origins Beige 2CM Antislip in 60 × 120 cm weighs approximately 42.2 kg/m² according to its listed packaging specifications.
Are thinner tiles always better for renovations?
No. They may reduce the floor build-up height, but can require particularly demanding substrate and installation conditions.
Can 20 mm slabs be installed on pedestals?
Some products are suitable for approved pedestal systems. Tile format, support layout, wind exposure, edge conditions and expected loads must be assessed.
Are thicker porcelain tiles always more resistant to breakage?
No. Thickness is only one factor. Material properties, format, support and installation quality are also important.
Conclusion: Choose Tile Thickness According to the Application
Whether a porcelain tile is 6, 9, 10, 12 or 20 mm thick, the best thickness is the one that is technically appropriate for the project.
Thin large-format slabs can provide elegant surfaces for approved walls and floors.
Conventional 9 or 10 mm porcelain tiles are suitable for numerous residential applications when correctly specified.
Twenty-millimetre porcelain slabs are particularly interesting for certain outdoor constructions.
The key is to assess the actual product, its technical data and the complete installation system.
At VITALE TILES, you can compare porcelain tiles, floor tiles and garden slabs for different projects.
If you need advice on thickness, substrates or suitable tile formats, contact VITALE TILES. Our team can help you select porcelain tiles for your project in Switzerland.