Bathroom Tiles: How to Choose Right

The bathroom is the most technically demanding room in any apartment. It has constant humidity of 70–90%, temperature fluctuations, aggressive cleaning agents and daily mechanical wear. Tiles chosen without understanding these conditions will peel or crack within 3–5 years. We have gathered everything that matters — from slip-resistance classification to laying technique — with no filler.

Before tiling: waterproofing — the stage you cannot skip

People think about the tiles first. They think about waterproofing last. This is a logical mistake: tile is not a waterproof material. Water penetrates through grout joints (especially cement-based ones), through micro-cracks in the adhesive and travels further — to the substrate, to the floor slab, to the neighbours below.

Waterproofing technology under tiles:

• Product: polymer-cement waterproofing — Ceresit CR 65, Mapei Mapelastic, Litokol Coverflex or an equivalent rated no lower than W8 (withstands 8 m of water column pressure)
• Application: 2 coats by brush or roller, each coat only after the previous one has fully dried (4–6 hours at 20°C)
• Wall upstand: minimum 30 cm — in the shower zone up to the level of the shower fitting plus 30 cm
• Corners: reinforcing tape Ceresit CL 152 or equivalent in all internal floor-to-wall and wall-to-wall corners
• Test: after curing — flood the floor with 5 cm of water, hold for 24–72 hours, check the neighbours' ceiling below

Two coats of polymer-cement waterproofing with reinforcing tape in the corners — a mandatory stage before any tiling in a bathroom.

Slip resistance: the key requirement for floor tiles

The international standard for assessing the slip resistance of ceramic surfaces is the R-class (DIN 51130). It is defined by the angle of inclination of a ramp at which a person in work footwear begins to slip. For residential bathrooms — minimum R9; for shower zones and wet floors — R10–R11.

An additional parameter is the PEI class (wear resistance): for bathroom floors — minimum PEI III, ideally PEI IV. PEI I–II is for walls only.

Tile formats: what works where

Large format 600×1200 and above

Creates minimal grout lines — which is both visually clean and hygienic. The main constraint: the substrate under large-format tiles must be perfectly flat. The allowable deviation is no more than 2 mm over a 2-metre straightedge. In older Tbilisi buildings this almost always requires a screed and full wall levelling.

Technical requirements: adhesive is applied to both the tile and the substrate (double-buttering technique), adhesive bed thickness 8–10 mm with a 10 mm notched trowel. Laying requires a highly skilled tiler — the tile must be "rolled" with a rubber mallet while checking level every 20–30 cm.

Subway tile 75×300 and 100×300

Rectangular tile in a brick-bond pattern is a universal solution. It works equally well in small (4–5 m²) and large bathrooms. Widely available in Tbilisi across both budget and premium segments (Atlas Concorde, Mutina). The herringbone layout adds dynamism but increases tile consumption by +15–20% due to cuts.

Subway tile 75×300 in brick-bond — a universal solution that works equally well in small and large bathrooms.

Adhesive and laying technique

Adhesive is selected by EN 12004 class. For bathrooms — minimum class C1T (cementitious, with reduced slip), for large format — C2TE (deformable, high-adhesion, elastic). Brands available in Tbilisi: Ceresit CM 115, Litokol K55, Mapei Ultralite.

Joint width — 2–3 mm for formats up to 300×600, 3–5 mm for large format. Less than 1.5 mm is technically incorrect: the tile destroys itself through thermal expansion.

Left: large format 600×1200 mm — minimal grout lines, maximum cleanliness. Right: classic white bathroom with feature tile inserts.

Grout: more important than it seems

Grout is the weak point of most bathrooms. Poor grout darkens, cracks and becomes a source of mould within 2–3 years. This is not the place to save money.

Cement-based grout

Widely available, the market standard. The downside — it is hygroscopic: it absorbs water and soap residue. Without maintenance it darkens and deteriorates within 2–3 years. Mandatory sealing with a protective compound (Litokol Litofin, Mapei Fuga Fresca) — immediately after laying and every 1–2 years thereafter. In shower zones, cement grout is only a temporary solution.

Epoxy grout

Two-component: resin + hardener. Does not absorb water, resistant to chemicals, does not darken, lasts 15+ years. Suitable for joints from 2 mm. Application is more demanding — the mix has an open time of 20–30 minutes and requires experience. Our recommendation: in shower zones — epoxy only (Litokol Starlike, Mapei Kerapoxy, Fuga Nano). On other surfaces — quality cement grout with sealing.

Laying patterns: comparison

Typical mistakes when choosing and laying tiles

• Buying tiles exactly to the floor area. A 10–15% buffer is mandatory. Matching the same batch by shade and calibre later will be difficult.
• Gloss tiles on the floor. Slippery and dangerous, especially in the shower. R-class on the floor — minimum R9.
• Not checking the shade. All tiles must come from the same batch (same calibre, same shade). Tiles from different batches look visually different even within one product code.
• Skimping on grout and adhesive. Poor grout ruins the look of expensive tiles. Poor adhesive guarantees delamination within 2–3 years.
• Ignoring the pattern when planning the layout. Tiles imitating wood or stone must be laid in a staggered pattern following the grain direction — this requires planning before purchase.

Frequently asked questions