Large-Format Tiles in the Bathroom: Fewer Joints, a Calmer Start to the Day

What large-format means in the bathroom

In the bathroom, tiles and slabs from about 60 by 120 centimetres are usually regarded as large-format. Beyond that there are sizes of 120 by 120, 120 by 260 and 160 by 320 centimetres, which can cover an entire wall from floor to ceiling. With the largest formats, people also speak of ceramic slabs.

These slabs are mostly made of porcelain stoneware, a densely fired ceramic with very low water absorption. They are available in many finishes: stone effect, concrete effect, plain colours, matt, textured or polished. Large formats can look very different, from calm and mineral to bold natural-stone patterns.

Why fewer joints bring more calm

A bathroom consists of many small elements: taps, mirror, glass, light fittings, accessories. If the surfaces behind them also break up into hundreds of small squares, the picture becomes restless. Large slabs create a calm backdrop.

There is also a practical advantage. Joints are where limescale, soap residue and dirt collect. Fewer joints mean less cleaning and less surface for discolouration. In the shower this is especially noticeable.

Small tiles have a weekly cost: the brush along the joints, the greying by the shower, an eye that wanders over the grid every morning. And with large slabs a wrong decision stays visible for the whole life of the bathroom, be it a tap beside a joint, a narrow strip at the door or a wall that was not skimmed first.

A bathroom with large slabs does not look like a tiled room. It looks like a room made of one material.

For Mr and Mrs B., that was the decisive thought. The tile was not the focus, but the room, which is allowed to disappear behind it. How such a material concept extends beyond the bathroom through the whole home is described in the article on the material concept as a golden thread.

Imagine the morning in the finished bathroom. The wall behind the shower is one continuous surface in a soft stone tone, with the mixer dead centre in a slab. Warm light slides across it. You step out barefoot onto the same material, and the only things you notice are the water and the quiet. But which format suits your bathroom?

Formats and thicknesses compared

Thin slabs of around 6 millimetres are lighter and particularly suited to walls. For floors, thicker slabs are usually used, which offer more resistance to breakage. The exact values depend on the manufacturer.

In small bathrooms, incidentally, large formats often work better than small ones, because they visually widen the room. More on this in the article Making a small bathroom feel large. But beautiful slabs depend on decisions made long before the first one arrives.

The joint plan: decisions before the first pipe

With small tiles it hardly matters if a tap sits two centimetres beside a joint. With large slabs it is noticed at once. That is why the planning of a bathroom with large formats begins with a joint plan, before the plumber lays the first pipe.

The joint plan determines:

1. Where the joints run: On walls and floor, ideally in relation to each other, so that wall joints continue on the floor.
2. Where the taps sit: Centred in a slab or exactly on a joint, never casually beside it.
3. Where niches go: Their edges should coincide with the joints.
4. How mirror, vanity unit and light fittings are aligned: They are matched to the grid.
5. Where cuts are made: Narrow leftover strips at corners or doors should be avoided.
6. Where movement joints lie: In all corners and at transitions to the bath, shower or glass, elastic joints are needed, even with large formats.

For Mr and Mrs B., the joint plan was drawn up together with the tiler and the plumber. The thermostatic mixer in the shower now sits exactly in the middle of a slab, the niche exactly between two joints. The vanity unit, made in our joinery Tischlerkultur, family-run since 1935, finishes flush at the edge of a slab. How to fit a made-to-measure vanity unit into such a grid is explained in the article on the made-to-measure vanity unit. Then comes what lies beneath the slabs.

Substrate and laying: where large formats are unforgiving

Large slabs forgive no unevenness. A wall that could be levelled with a little more adhesive for small tiles must, with large formats, be skimmed beforehand or rebuilt. Otherwise so-called lippage arises: edges that stand slightly proud at the joints and are clearly visible in raking light.

The laying itself follows clear rules:

• Full-bed laying: The adhesive is applied to the substrate and to the back of the slab so that no voids remain. Hollow spots can lead to breakage.
• Suitable adhesive: For large formats, flexible adhesives are used that absorb movement in the substrate.
• Levelling systems: Small clips and wedges hold neighbouring slabs at the same height while the adhesive sets.
• Narrow joints: With rectified, that is precisely ground, edges, joints of about 2 to 3 millimetres are possible.

In an Altbau (a pre-1945 Viennese apartment building), the question also arises whether walls and floors are sufficiently load-bearing and stable. Timber-joist floors move more than concrete floors, which has to be taken into account with large floor slabs. We clarify this case by case, with a structural engineer if necessary. And the shower, where the floor has to do more than look good?

Large formats in the shower

In the shower the floor needs a fall so that the water drains away. With a point drain in the middle, a fall from four directions results, which would require large slabs to be cut diagonally. That contradicts the idea of the large format.

The more elegant solution is a linear drain along the wall. It allows a fall in one direction only, and the slab remains a flat, gently sloping surface. In this way the bathroom floor can pass into the shower without interruption. How falls and drains work is described in the article on the walk-in shower.

A slip-resistant finish should be chosen for the shower floor. Many manufacturers offer the same slab in one version for dry and one for wet barefoot areas. That keeps the look uniform.

On a Saturday morning, a squeegee and a cloth are all it takes. There are no dark lines to scrub, and the floor flows into the shower without a ridge under your foot. One practical question remains: can the slab get up your stairs?

Transport and cutting: logistics in a Viennese Altbau

A slab of 120 by 260 centimetres does not fit into every lift. In a Viennese Altbau, lifts are often small or retrofitted, and stairwells have tight turns. Before large formats are ordered, we therefore check the route from the van to the bathroom: door widths, stair turns, lift depth, corridor widths.

Large slabs are transported with carrying frames and suction lifters, usually by two to three people. Cut-outs for taps, sockets or drainage channels are made on site with specialist tools or beforehand in the workshop. This takes experience, because a broken large-format slab is an expensive loss and often means weeks of waiting for a replacement.

The most beautiful slab is no use if it gets stuck on the stair turn on the second floor.

For Mr and Mrs B., the route was easy; the house has wide stairs. In Josefstadt or in the 8th district we might have chosen a smaller format for the same bathroom, about 120 by 120 centimetres, and still achieved a very calm surface. Is there another route to a calm bathroom?

Alternatives and cost

Large-format ceramic is not the only way to a calm, low-joint bathroom. Depending on your requirements, other materials come into question too.

• Cosentino Dekton: Ultra-compact slabs in large formats, very resistant to scratches, heat and stains. Dekton is suitable for walls, shower floors and vanity tops. More in Dekton explained.
• Natural stone in large slabs: Warmer and livelier in appearance, but with its own care requirements. Which stones work in the bathroom is described in the article on natural stone in the bathroom.
• Micro-cement and trowelled finishes: Truly jointless, but with limits on durability and application. More in the article Jointless: micro-cement and trowelled finishes.
• Terrazzo: A Viennese classic with its own history, see Terrazzo for floor and vanity unit.

As for cost: large-format slabs are often no more expensive in material than high-quality small tiles. The laying, however, is more demanding, because substrate, handling and cutting require more work. Per square metre, laying costs are therefore usually well above those of standard formats. What a complete bathroom renovation in Vienna costs depends on the project, and a reliable estimate comes in the free first conversation, without obligation. More about our work on the page bathroom renovation, and insights into finished bathrooms under bathrooms.