Modular wall tiles: complete selection guide 7 sizes

By Osman Orman · Tile and technical specialist at Tegelmonsters

Modular wall tiles are tiles that come in multiple coordinated sizes, allowing you to combine them into a size mix based on a fixed dimensional logic.

This dimensional logic is derived from a shared grid. Once understood, you place sizes side by side without fitting problems and plan the tiling more tightly.

System

What are modular wall tiles and how does the system work?

A modular system means that the manufacturer designs the sizes on a common grid dimension. A series then contains, for example, 30×30, 30×60, and 15×60 cm, all of which fall within the same pattern. The international standard ISO 13006, published in Europe as EN 14411, describes the concepts that make this possible: the nominal dimension as an indication, the working dimension as the production dimension, and the coordinating dimension as the working dimension plus the joint.

The advantage lies in predictability. When two formats are aligned with the same coordinating dimension, the joints of one format align with those of the other. This reduces fit loss at the edges and creates a calm wall appearance. For the architect working with multiple disciplines, a modular series is therefore easier to plan than individual formats from different series.

The difference compared to a standard format selection lies in the coordination. Two random tiles of 30×60 and 30×30 cm do not necessarily have to be combined, as their working dimensions and caliber may differ. Within a modular series, however, this coordination is precisely the starting point. For the complete standard basis of a tile specification, our guide to wall tile specifications explains how to define classification, format, and adhesive together.

Size coordination

How do modular size, working size, and coordinating size relate?

The three dimensions are described in ISO 13006. The nominal dimension is the name you see in the catalogue, which does not have to be an exact measurement. The working dimension, denoted by the letter W in the standard, is the dimension at which the manufacturer produces within a permissible deviation. The coordinating dimension, denoted by C, is the working dimension added to the joint width. The relationship is simple: C equals W plus the joint.

A calculation example makes it concrete. A modular tile with a nominal size of 15×15 cm is often produced with a working dimension of 147×147 mm. If you lay this with a 3 mm grout joint, the coordinating dimension is 150×150 mm. A tile with a nominal size of 15×30 cm in the same series has a working dimension of 147×297 mm and a coordinating dimension of 150×300 mm. Both therefore fall within a 150 mm grid.

That calculation step is the core of modularity. Because all formats align with the same grid, a joint never shifts halfway across a plane. The ISO 13006 standard and the measurement method for dimensions are managed in the Netherlands via NEN , where you can find the current version of the tile standards. For projects, this means that you can draw up the grid during the design phase, long before the tiles are laid on the construction site.

Formats

Which formats to combine in a modular wall tile system?

A modular family is created by dividing or multiplying a base size. If you start with a 30 cm grid, then 30×30, 30×60, and 15×30 cm fit into it, because their coordinating sizes are 150 or 300 mm. This principle is visible as a trend at trade fairs such as Cersaie in Bologna, where manufacturers are increasingly showcasing entire size families within a collection rather than individual sizes.

The choice of base size dictates the wall appearance. A fine 15 cm grid creates a detailed, tactile surface suitable for accent walls and smaller spaces. A coarse 60 cm grid looks calmer and is popular for large surfaces. By mixing within a family, you achieve both effects in a single surface without the pattern becoming cluttered.

For large wall surfaces, a modular range complements larger formats well. You can read how format dictates the choice of adhesive, grout, and transport in the context of our large-format tile range . For a subtle accent in a modular mix, the small formats from the mosaic category offer a complement that fits the same grid.

Kaliber

What role do caliber and tolerance play in modular tiles?

ISO 10545-2 specifies the measurement method for dimensions and surface quality. The standard establishes tolerances for length, width, thickness, straightness of the sides, squareness of the corners, and flatness. For rectified tiles, with tightly ground edges, the permissible deviation is tighter than for tiles with a natural edge. Rectification means that the manufacturer grinds the edges to the exact size after firing, allowing for installation with a narrow grout joint.

The caliber indicates the actual production size within that margin. For example, a manufacturer supplies a nominal size of 30 cm in caliber W1, W2, or W3, each slightly different. This makes little difference for a single wall, but it is a major factor in a modular mix: if you lay two sizes from different calibers, the 150 or 300 mm grid is no longer correct, and the joints will run crooked.

For installation, this means maintaining a batch in a specific caliber and having deliveries arrive per caliber. The water absorption of the tile partly determines how stable that size remains under moisture. Which absorption class suits which room can be found in our selection guide for water absorption of ceramic tiles . The performance requirements for wall and floor finishes in buildings can be found on Bouwbesluit Online.

Laying patterns

Which laying patterns suit modular wall tiles?

The laying pattern determines how the modular system becomes visible. Stack bond, where the joints run directly above each other, emphasizes the grid and appears calm and contemporary. Half-brick bond offsets each row by half and creates a classic, brick-built look. An opus pattern combines multiple sizes in a fixed repetition, resulting in a lively surface that nevertheless follows a logic.

The grout plays a role in the effect. A tone-on-tone grout allows the pattern to be read subtly, while a contrasting grout accentuates the grid. For public spaces and the hospitality industry, grout in a shade darker than the tile is often more practical, as cleaning and graying are less visible. You can find out which wear class and anti-slip value apply per room in our selection guide for PEI value per room . The PEI value indicates how wear-resistant the tile is.

The manufacturers in our range often design their series around a fixed size family. Pamesa Ceramica from Spain, known for a wide range of porcelain stoneware, supplies wall tiles with consistent calibration that supports a mix of sizes within an opus pattern. Porcelain stoneware is a highly compressed, dense ceramic with low water absorption. Because the calibration is consistent throughout the entire range, the sizes in an opus mix fit into the same grid.

Specification

How do you specify modular wall tiles in a project?

The specification starts with the format family. Note which formats you are mixing, for example 30×60 and 15×60 cm from the same grid, indicating whether they are rectified or not. Next, define the caliber so that all formats come from the same production run. The joint width is determined by the edge finish: 2 mm for rectified tiles, 3 to 4 mm for tiles with a natural edge.

The pattern belongs in the same row. An opus mix requires a laying plan showing the ratio between the sizes, so that the tiler can mark out the repeat. For a wall that needs to appear as a closed surface, choose a stack bond with a narrow joint. The complete standard basis for the corresponding adhesive and grout selection can be found in our guide to wall tile specifications.

Sample package

How do you put together a sample pack for a modular wall project?

On the wall tile filter of the assortment at tegelmonsters.nl, you can select by size, color, and finish for free. For a modular project, set the filter to sizes within a series and bundle the sample request per project via the Sample Folder. This keeps the size family together and prevents you from accidentally ordering sizes from different calibers.

What project managers often tell us: the initial selection takes place online, followed by the physical assessment of the format mix in our showroom in Utrecht. The showroom is accessible to professionals by appointment only and offers actual-size samples alongside sample surfaces. Our manufacturers from Spain and Portugal showcase their format families annually at Cersaie and provide datasheets with coordinating dimensions, allowing you to draw the grid directly from the delivery documents.

Frequently asked questions