Large-Format Tiles: Advantages and Disadvantages for Trade and Clients

Tiles with an edge length of 60 or 120 centimetres have long ceased to be a special request; in most series they stand on an equal footing with the classic sizes. The visual effect is undisputed: a room looks calmer when there are fewer joints in it. Whether a large format is the right choice for a specific project, however, is rarely decided on looks. It is decided by the substrate, by the available tools and by the question of who ultimately carries, cuts and aligns the slabs. This article sorts the advantages and disadvantages as they occur in practice – for trade businesses as much as for clients facing the material decision.

What Large Format Means Today

There is no official definition of the term large format. In the technical literature one delimitation has become established: the guidance document “Großformate” issued by the Fachverband Fliesen und Naturstein, the German trade association for tiling and natural stone within the Zentralverband des Deutschen Baugewerbes, considers tiles with edge lengths between 60 and 120 centimetres. Anything beyond that – ceramic panels up to around three metres in length, often in reduced thicknesses – follows further rules of its own for transport, cutting and installation and belongs in the hands of specialist contractors.

In practice, the effort shifts noticeably from around 60 centimetres of edge length. From this size on, the covering reacts more sensitively to every unevenness in the substrate, and the processing steps that were still optional at 30 × 60 become obligatory. Formats such as 60 × 120 cm are therefore regarded in many businesses as the entry point into large-format tiling, not as a variant of the standard format.

Two product characteristics matter more when selecting than they do with small formats. Rectified material is trimmed to an exact dimension after firing and allows narrower, more even joint patterns than merely calibrated material. And the material thickness determines what load the covering can take: thin slabs save build-up height and weight, but forgive voids in the mortar bed even less than thick ones.

Not every large format is a large square format. Between 60 × 120 and 120 × 120 centimetres there is a clear difference in handling: an elongated format can still be guided safely by two people and arranged in many rooms without forced cuts, whereas a square large format lays down more surface at once and correspondingly leaves less room for correction. Anyone working with large formats for the first time will generally do better with the elongated format.

Advantages: Appearance, Fewer Joints, Cleaning

The most obvious advantage is the calmer image. A floor covering made of a few large elements does not visually break the room down into a grid but lets it be perceived as a coherent surface. Especially in small to medium-sized rooms this looks more generous than the number of square metres would suggest. Material effects benefit additionally: a continuous structure in a concrete look or a stone grain only looks credible when it is not interrupted by a joint every 30 centimetres.

The second advantage has a building physics basis and is often underestimated. The sensitive point of a ceramic covering is not the tile but the joint. Grout picks up dirt, discolours over the years and is the place where cleaning agents and mechanical loads attack first. Anyone who reduces the number of linear metres of joint per square metre also reduces the surface that ages. That is not an argument for a jointless covering – there is no such thing with ceramics, every installation needs joints to absorb dimensional tolerances and movements – but it explains why large formats feel easier to look after in everyday use.

In the bathroom a third point is added. If wall and floor are executed in the same material and in a large format, there are fewer junctions and fewer visible cuts – for instance at level-access showers, in niches or at pre-wall installations. The result is a bathroom that is not structured by a grid of joints but by the sanitary fixtures themselves.

One frequently cited advantage, by contrast, deserves a qualification: that large formats are quicker to lay because fewer pieces have to be set. That is only true for the pure laying time on large, clear and flat surfaces. Once substrate preparation, cutting and the necessary second person are taken into account, the advantage frequently reverses in small-scale rooms. Time saving is therefore not a sound argument for a large format – the appearance and the reduced amount of grout are.

Disadvantages: Substrate, Waste, Tools

The most important disadvantage is sensitivity to the substrate. A large, stiff slab can no longer compensate for unevenness, it reveals it. The flatness tolerances that DIN 18202, the German standard on dimensional tolerances in building construction, permits for structural floors are generally not sufficient for large formats; DIN 18157, the standard for thin-bed tiling, expressly requires unevenness to be levelled out beforehand. In practice this means: check, level, if necessary use a self-levelling compound – and allow for this effort from the outset. Anyone working on an existing screed should also assess its condition; which checks make sense here is described in our article on tiling over old screed.

There is also the bow of the tiles themselves. The product standard EN 14411 permits a deflection at large edge lengths which at 1.20 metres may amount to several millimetres in calculation terms without the material being defective. This is why the buttering-floating method is regarded as the standard procedure for large formats: the adhesive is applied both to the substrate and to the back of the tile so that a mortar bed with as few voids as possible results. With large formats, voids are not merely an acoustic nuisance but a breaking point – above all under point loads.

The joint pattern allows less freedom than many clients expect. Joints of one to two millimetres, as are frequently requested, are considered too narrow for large formats to absorb dimensional tolerances and movements; the technical literature recommends joint widths from about three millimetres for these formats. The bond is restricted as well: a half offset, as is usual with small formats, means that the bow of one slab meets exactly the middle of the neighbouring slab's joint, producing noticeable lippage. Considerably smaller offsets or a stack bond are therefore customary.

The third block concerns handling and waste. A slab in the 120 × 120 centimetre format weighs, depending on thickness, well over 30 kilograms and can hardly be swung into position accurately on your own – suction lifters and a second person are standard, not luxury. Cutting requires cutting systems with a correspondingly long rail, and cut-outs for pipe penetrations generally call for a wet cutter. And in small-scale, angular floor plans more waste arises than with small formats, because every cut piece uses up a whole slab. Later repairs are also more demanding: individual slabs can only be replaced with considerable effort, which is why keeping a reserve from the same batch in storage is worthwhile.

In summary, these are the points that should be checked before deciding on the format:

• Flatness of the substrate – checked and, where necessary, levelled, not merely eyeballed
• Installation method: buttering-floating with a low-void mortar bed, a suitable notched trowel system and a suitable adhesive mortar
• Tools: cutting system with a sufficiently long rail, wet cutter for cut-outs, suction lifters, levelling system
• Personnel: at least two people for transport and positioning
• Joint pattern: define the joint width and bond in advance and agree them with the client
• Logistics: delivery, storage on site and a reserve from the same batch

When Classic Formats Are the Better Choice

There are situations in which a smaller format is objectively the better solution. The clearest of these is falls. A level-access shower with a point drain requires a fall running towards the drain from all sides – a large, stiff slab cannot follow this funnel shape and would have to be cut up. Either the shower area is executed in a small format or mosaic, or the drainage is switched to a channel that only needs a fall in one axis. This decision is made in the planning, not during installation.

The same applies to bathrooms in existing buildings with uneven walls, sloping ceilings or many corners. There the levelling effort rises faster than the visual gain, and every cut piece costs a full slab. Stairs, plinth areas and heavily structured surfaces are also typical cases in which medium formats remain the more economical and technically cleaner choice. Which size suits which bathroom layout is something we deal with in more detail in our guide to tile size in the bathroom.

Not least, it is a question of time and calculation. Large formats require more preparation, more personnel per square metre and more tools. For a business that keeps this equipment anyway, that is no obstacle. For a small bathroom that is meant to be finished in a day, it is.

An intermediate route is often overlooked: you do not have to decide on one format per room. In many projects the large, clear surface is executed in a large format and the small-scale area – shower tray, niche, stair landing – deliberately in a smaller format from the same series. The prerequisite is that the series offers both formats and that the colours come from comparable batches. That is to be clarified when ordering, not on delivery.

Private and Commercial: Two Scenarios

In private new builds, much speaks for the large format. The screed is fresh, flat and can still be corrected before tiling, the floor plans are usually straight, and the surface will remain unchanged for decades. A living area or a larger bathroom in 120 × 120 cm is a decision that is rarely regretted here. It looks different in an existing bathroom of four or five square metres in which three doors, a window and a pre-wall meet: there the smaller format usually leads to the calmer result, because fewer forced cuts arise.

In a commercial setting – retail areas, foyers, medical practices – two criteria are added that play a smaller role in residential use. First, slip safety: separate requirements for slip resistance apply to work areas and publicly accessible surfaces, and these have to be clarified before the material is selected. Second, availability for reordering: series are discontinued, and a property whose surfaces are repaired in sections over ten years needs either a stored contingent or a format that can still be added to later.

The same advice applies in both cases: the format decision should be made before the substrate is created – not afterwards. If you are planning a specific project in the Kreis Mettmann or the Düsseldorf area and are unsure whether your substrate and your floor plan will carry a large format, get in touch with us. We will look at the constraints before material is ordered.