Complete guide

Tile Laying

Learn to tile bathrooms, kitchens and hallways — with the correct waterproof membrane, drainage fall towards the drain, and professionally finished grout joints. This guide covers everything from substrate preparation to the final silicone bead.

Wet roomsMembraneTile adhesiveGroutingFloor drain

What is tile laying?

Tile laying involves bonding ceramic or natural stone tiles to floors and walls using tile adhesive, then filling the gaps with grout. In bathrooms and wet rooms, building code requirements also mandate a waterproof membraneⓘwaterproof membraneA continuous watertight layer between the substrate and tiles that prevents moisture from reaching the structural elements. Required by building code in all wet rooms. beneath the tiles.

A properly executed tile installation lasts for decades with minimal maintenance required. Poor workmanship can lead to moisture damage behind walls and in floor structures — repairs that quickly cost many times more than the original tiling job.

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When should you hire a professional? Tiling in bathrooms and wet rooms is classified as "wet room work" and should be carried out by a qualified tradesperson if you intend to sell the property. For personal use you can do it yourself, but the membrane work is critical and should be documented with photographs.

Planning

Choose the right tile format

The tile format affects waste, labour time and the visual result. Large-format tiles create an open feel but require a flatter substrate and more precise drainage falls. Small mosaic tiles tolerate surface irregularities better.

Format	Typical use	Min. joint width	Notes
Mosaic (≤ 5×5 cm)	Shower area, feature details	2 mm	Supplied on mesh; ideal near floor drain
10×10 – 20×20 cm	Bathroom, hallway	2–3 mm	Easy to handle, minimal cutting
30×30 – 60×60 cm	Floors and walls, kitchen	3–5 mm	Most common format for bathrooms
60×60 – 120×60 cm	Large bathrooms, living rooms	4–6 mm	Requires level substrate (±3 mm/2 m)
> 120 cm (large format)	Statement look, minimal grout	6–10 mm	Demanding installation; recommended to use a professional

Laying patterns and waste

The laying pattern determines how many tiles end up as cut waste (waste allowanceⓘwaste allowanceThe proportion of tiles lost to cuts along edges, around pipes and at pattern changes. Always purchase more than the calculated area.).

Tile materials

Ceramic

Most affordable and easiest to cut. Used on interior walls and floors. Not frost-resistant.

Porcelain

Dense, hard and frost-resistant. Suitable for all applications including terraces and outdoor areas.

Natural stone

Slate, marble, granite. Decorative, but porous — requires sealing before grouting.

Wet room requirements

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Wet rooms require a continuous waterproof membrane under the tiles. A missing or defective membrane is one of the most common and costly construction defects in residential buildings. Always check local building codes and manufacturer instructions before starting work.

Waterproof membrane

Outside the shower zone: membrane minimum 200 mm above finished floor level. Shower zone: full height, typically 2,000–2,400 mm. Continuous and unbroken.

Drainage fall to drain

Shower zone: minimum 1:50 (2 %) fall towards the drain. Outside the shower zone a lower gradient may be used. Measured from the finished tile surface.

Drain connection

The membrane must be fed down into the drain collar and secured mechanically. No penetrations through the membrane are permitted without an approved seal.

Joint tape in corners

Reinforcing joint tape must be embedded in the membrane at all internal corners (floor–wall and wall–wall) to prevent cracking caused by structural movement.

Tile water absorption and frost resistance

Ceramic tiles are classified by water absorption group, which determines frost resistance and suitable applications.

Group	Water absorption (E)	Frost resistance	Suitable for
Ia	E ≤ 0.5 %	Yes — frost resistant	All applications incl. exterior, unheated floors
Ib	0.5 % < E ≤ 3 %	Generally resistant — verify with manufacturer	Interior + protected exterior
IIa	3 % < E ≤ 6 %	Not reliably frost resistant	Interior only
IIb / III	E > 6 %	Not frost resistant	Interior walls only

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Exterior tiles: Only Group Ia tiles (E ≤ 0.5 % — typically full-body porcelain) are reliably frost resistant. Never use Groups IIa or higher outdoors in climates with freeze-thaw cycles.

Layer build-up — cross-section

Materials and tools

Tile adhesive — classification

Tile adhesives are classified by type (C = cementitious, D = dispersion, R = reaction resin), strength class and flexibility. For wet rooms, always use a minimum of C2 S1 (improved, deformable). On wood subfloors or balconies: C2 S2.

Class	Properties	Application
C1	Standard cementitious adhesive (≥ 0.5 N/mm²)	Dry rooms, interior walls only
C2	Improved cementitious adhesive (≥ 1.0 N/mm²)	Wet rooms, outdoor — minimum for showers
C2 S1	Deformable — transverse deformation 2.0–5 mm	Wet rooms, underfloor heating, floating screed
C2 S2	Highly deformable — > 5 mm	Wood subfloors, balconies, terraces, pool surrounds
C2 F	Fast-setting (handling strength < 6 h)	Time-critical work, repairs
T (suffix)	Anti-slip / reduced slippage (≤ 0.5 mm slip)	Always use on wall tiles — C2 T for wet room walls
E (suffix)	Extended open time (≥ 30 min)	Large-format tiles, hot/dry conditions

Grout — EN 13888

Grout fills the joints between tiles and gives the surface a neat, finished appearance. All grout products sold in the EU/EEA must carry CE marking (EN 13888). In wet rooms, always specify CG2 WⓘCG2 WImproved cementitious grout (CG2) with water-resistant properties (W suffix — water absorption ≤ 5 g after 30 min). EN 13888 requirement for wet rooms. CG1 lacks the W designation and must not be used in showers. or RG (reactive/epoxy) grout. CG1 must not be used in wet rooms — it lacks the water-resistance (W) designation.

Tool list

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Notched trowel— 6–10 mm notch size depending on tile format

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Tile cutter or angle grinder— Diamond blade required for porcelain and natural stone

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Rubber mallet— For tapping tiles into adhesive without cracking them

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Tile spacers— 2–6 mm depending on the chosen joint width

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Spirit level (1 m and 2 m)— For checking flat surface and drainage fall

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Grout float (rubber)— For pressing grout into the joints

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Sponge and bucket— For cleaning excess grout from tile faces

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Silicone gun— For corner joints and transitions

Step by step

The substrate must be clean, stable and dry. Loose paint, dust and grease prevent the adhesive from bonding.

Grind away loose concrete, filler or flaking paint
Fill cracks and holes with repair mortar — allow to cure fully
Moisture check: relative humidity in the concrete must meet the adhesive and membrane manufacturer's requirements (typically <85–90 % RH; 75 % with underfloor heating). Use a moisture meter or the plastic sheet test method
Apply primerⓘprimerA priming coat that reduces substrate absorption and improves bond between substrate and adhesive or membrane. Important on porous concrete and existing tiles. to absorbent surfaces — allow to dry

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Existing tiles can be tiled over if they are firmly bonded, degreased and primed, and the correct adhesive is used. Check by tapping with your knuckles — a hollow sound indicates loose tiles that must be removed.

In all wet rooms, the membrane is applied before the tiles. This is one of the most critical steps — take your time and do it carefully.

Bed joint tapeⓘjoint tapeReinforced fabric tape embedded in all internal corners (floor–wall, wall–wall) to seal and reinforce the membrane against cracking. into all internal corners
Roll or brush on the first coat of liquid membrane — apply an extra-thick coat over corners
Allow to dry (follow the product data sheet; typically 2–4 hours)
Apply a second coat at right angles to the first
Membrane upstand: outside shower zone at least 200 mm; shower zone full height (2,000–2,400 mm)
Allow the membrane to dry completely (typically 24 h) before laying tiles

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Check that the floor drain is correctly set and that the membrane is fed down into the drain collar and secured with the clamping ring. An unsecured drain is a leading cause of water damage.

Good planning before the first tile goes down saves a great deal of time and waste material.

Measure the room and find the centre point — snap a chalk line in both directions
Dry-lay a row of tiles from the centre out to the wall without adhesive — check whether you end up with unsightly narrow slivers
Adjust the starting point so that you have at least a half tile at both sides
In the shower zone: always place whole tiles at the drain and against the shower wall
Mark the grid on the floor with a marker pen to keep your bearings as you work

Always start from the centre and work towards the walls. Never tile yourself into a corner.

Mix adhesive according to instructions — let it slake for 5 minutes, then stir again
Apply with the notched trowel at 45° to the tile joint for consistent ridges
For large-format tiles (side > 60 cm): back-butteringⓘback-butteringTile adhesive is applied to both the substrate and the back of the tile. Ensures 100% contact — recommended for large format and required for outdoor use. is recommended
Tap the tile gently into place with the rubber mallet — check with spirit level
Insert tile spacers immediately
Remove excess adhesive from the joints with a stick — adhesive in the joint will ruin the grout
Allow adhesive to cure for at least 24 hours (48 h at lower temperatures) before grouting

Wall tiles are installed from the bottom up. Always use T-rated adhesive (reduced slippage) on walls.

Fix a horizontal batten along the bottom as a starting line (remove after adhesive cures)
Apply adhesive to the wall in sections you can cover within 20–30 minutes
Start from the centre and work towards the corners
Check alignment regularly with a spirit level — wall tiles can creep downward
Cut tiles around sockets, pipe penetrations and edges with an angle grinder

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Pipe penetrations and light switches: cut the hole 2–3 mm larger than the pipe. The gap will be covered by an escutcheon or face plate and sealed with silicone.

Remove all tile spacers. Grouting must always be done after the adhesive has fully cured.

Mix grout to a creamy consistency — let it stand for 5 minutes, then stir again
Press the grout diagonally into the joints using the grout float
Work in sections of approximately 1 m² at a time
Wipe off excess with a damp sponge in a diagonal motion — never along the joint
Allow to haze for 20–30 minutes, then buff off the film with a dry cloth
Grout reaches full cure after 24–72 hours — do not load with water during this period

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Natural stone absorbs grout and can become permanently stained. Always seal natural stone with a stone impregnator before grouting.

Corners and transitions must always have silicone — never cement grout. Structural movement will crack cement grout in internal corners.

Floor–wall junction, all internal corners and junctions with bath and shower enclosures: tape off and fill with neutral-cure silicone
Smooth with a dampened finger or dedicated tool
Remove the tape while the silicone is still fresh
Allow silicone to cure for 24 hours before contact with water
Fit escutcheons, cover plates and trim after the silicone has cured

Common mistakes — and how to avoid them

Ready to calculate your materials?

Use the calculator to find the exact number of tiles, quantities of adhesive, grout and membrane — with waste allowance and pricing included.

Open tile calculator

Frequently asked questions

How much waste should I add for tile installation?

Add 10–15% waste for straight patterns and 15–20% for diagonal layouts. Complex rooms with many cuts require more.

What grout width should I use?

Standard grout width is ⅛" (3mm) for wall tiles and ³⁄₁₆" (5mm) for floor tiles. Larger format tiles (>24") should use at least ⅛" grout joints.

Do I need a waterproof membrane in a bathroom?

Yes. All wet areas (showers, tub surrounds) require a waterproof membrane behind the tile. Membrane should extend at least 6" up the wall and be sealed around all penetrations.

References

→ Mapei — tile adhesive and grout product selection guide
→ Ardex — technical documents for tile installation systems
→ TTFA — Tile Association installation guidance and adhesive classification
→ BDA (British Decorators Association) — substrate preparation for tiling
→ EN 12004 / ANSI A118 — tile adhesive classification standards (available via your national standards body)

Adhesive and grout quantities are indicative. Coverage depends on tile size, joint width and substrate condition. Always check the product data sheet. Last reviewed: May 2026