ISO 13006 for Ceramic Tiles: Classification & Standards

ISO 13006 for Ceramic Tiles: What Does It Mean?

When it comes to buying ceramic or vitrified tiles, the visual appeal is just part of the game. What’s more, there are different technical aspects behind a tile’s colour, finish and design that affect the quality and performance. This is why ISO 13006 for ceramic tiles is crucial.

ISO 13006 is a worldwide standard for the terminology, classification, features and labelling of ceramic tiles. The currently released version is ISO 13006:2018 which has been withdrawn and confirmed by ISO in 2024. It divides tiles mainly on the basis of the manufacturing process and water absorption.

But what do the codes BIa, BIb, BIIa and BIII really stands for? Why do architects, designers, dealers and homeowners really need to know them?

Let's simplify the standard to a simple and practical one.

What Is ISO 13006 for Ceramic Tiles?

ISO 13006 provides an international framework for describing ceramic tiles. It sets out their definitions, categories, performance characteristics and labelling requirements, covering first-quality tiles made by extrusion or dry pressing.

 A key part of the standard is water absorption—the proportion of water a tile takes in compared with its own weight. Tiles are assigned to Groups I, II or III according to how much water they absorb. These groups are further split by production method and absorption level.

 As a result, ISO 13006 helps buyers compare tiles on practical specifications as well as appearance, including colour, texture and finish.

How Does ISO 13006 Classify Ceramic Tiles?

The classification system considers two key factors: how the tile is manufactured and how much water it absorbs.

The manufacturing method is represented by a letter:

A = Extruded tiles
B = Dry-pressed tiles

The water absorption category is represented by the Roman numeral and additional letters.

For dry-pressed tiles, for example:

These limits are defined by ISO 13006:2018. Group I represent absorption of up to 3%, Group II covers more than 3% up to 10%, and Group III covers absorption above 10%.

Understanding this classification can make technical tile specifications much easier to interpret.

What Does BIa Mean?

Bla tiles are dry pressed ceramic tiles whose water absorption is not more than 0.5%.

This falls under one of the lowest categories of water absorption, under the ISO 13006 system of classification. Due to the low water absorption, the BIa designation is of more significance in the case of compact ceramic tile.

But one crucial bit is missed out: the classification ISO itself does not impose any tile to be used in a certain place. The classification sets out groups of products without determining to which products those groups refer. The decision to apply should be based on the full array of anticipated performance needs.

This distinction is critical when choosing tiles for residential, commercial or architectural applications.

What Does BIIa Mean?

BIIa are unglazed ceramic tiles with water absorption exceeding 3% and not more than 6%.

BIIa denotes a higher value of water absorption than BIa. Hence, it is classified under Group II as medium water absorption, as per ISO 13006.

This categorization is useful for architects and designers to aid in assessment of product datasheets while considering options for ceramic tile. But water absorption is not the only property that should be considered, depending on the application, you might find the strength, resistance to abrasion or the surface characteristics should also be considered.

What Does BIII Mean?

BIII categories are defined in dry-pressed tiles having a water absorption greater than 10%. Group BIII includes glazed tiles under the ISO 13006:2018.

This higher category of absorption explains how reading the technical classification may give you an information which is not immediately visible from the look of a tile.

Two tiles can have the same appearance but very different technical characteristics. Looking at the product specification enables the professional to choose based on quantifiable performance rather than just looks.

Is ISO 13006 the Same as a Tile Quality Certificate?

Not quite.

This is one of the most crucial things to know when it comes to ceramic tile quality levels.

It defines classifications, features and marking requirements (ISO 13006:2018). It is not to be read as a kind of "all tile with ISO reference = `high quality' ".

Depending on the use and type of tile, the standard-child's play, includes characteristics-related requirements of sizes and surface quality, water absorption, breaking strength, modulus of rupture and resistance to abrasion.

In short, Using ISO 13006 you can have a technical terminology to designate and define ceramic tiles.

ISO 13006 and ISO 10545: What Is the Difference?

ISO 13006 and the ISO 10545 series are complementary but have different objectives.

The ISO 13006 defines how to classify ceramic tiles as well as their properties and how to mark them. ISO 10545 contains equivalent test procedures to assess different tile properties. The current description for the ISO committee states explicitly that the test methods included in ISO 10545 are those necessary for testing for the properties identified in ISO 13006.

For example, ISO 13006 references testing for properties such as:

·       Water absorption

·       Breaking strength

·       Modulus of rupture

·       Dimensional characteristics

·       Surface quality

·       Abrasion resistance

Understanding this difference is part of why a technical tile datasheet may list both ISO 13006 and the individual ISO 10545 test standards to tile professionals.

Why Does ISO 13006 Matter When Choosing Tiles?

For the tile buyer, architect, or interior designer, the tile's look is just the starting line.

Technical details can also assist in a few more practical queries:

How long does the tile take to absorb water?

What manufacturing group is it?

What performance tests were conducted?

Is the application suitable for the product specification?

ISO 13006 has made the technical classification more systematic. Rather than comparing tiles just for color, finish or pattern, the professional can now compare factual parameters.

This is particularly useful in situations where the performance of the floor, the moisture exposure, the durability and the adherence to spec.

What Should You Check on a Tile Datasheet?

When assessing the specifications of ceramic tile, don’t just rely on the ISO classification code.

Check out the full technical datasheet. Information may be relevant according to product and application, such as water absorption, size, thickness, strength at breaking, surface quality, resistance to abrasion and other physical or chemical characteristics.

Ordering information shall, in addition to other relevant property details such as size, thickness, type of surface, color, profile for glazed tiles also define the class of abrasion and other relevant properties.

This is what makes the technical data sheet so crucial for architects, designers, dealers and project procurement teams.

ISO 13006: A Technical Language for Better Tile Selection

A tile’s appearance may suggest quality, but its technical specifications reveal more about how it’s made and where it may be suitable.

ISO 13006 offers a consistent system for classifying ceramic tiles by their manufacturing method and water absorption. Labels such as BIa, BIb, BIIa, BIIb and BIII make it easier for professionals to compare products using the same criteria.
These classifications are useful, but they’re only part of the picture. Choosing the right tile also means considering other performance measures and the needs of the project.
At Firedclay Originals, we believe informed choices start with clear product information. Knowing standards such as ISO 13006 mean can help architects, designers, developers and buyers assess tiles beyond their appearance.
A good tile choice isn’t just about what you see. It’s also about knowing what the product is designed and tested to do.