Tiling Tips for Beginners: Avoid These Costly Mistakes

Start With the Right Materials

Before you pick up a trowel, you need to know exactly how many tiles, how much adhesive, and how much grout to buy. Our tile calculator gives you precise quantities including a waste allowance, so you do not run short mid-project or overbuy.

Here is a quick reference for material quantities per square metre:

Material	Quantity per sqm
Wall tiles (20 x 25 cm)	~20 tiles
Floor tiles (30 x 30 cm)	~11 tiles
Large format (60 x 60 cm)	~3 tiles
Tile adhesive	3–5 kg
Grout	0.3–0.5 kg
Spacers (3 mm)	~50

Always order 10–15% extra tiles. Even experienced tilers break a few during cutting, and having spares from the same batch means consistent colour if you need replacements later. Use our tile waste calculator for more precise waste figures.

Tip 1: Prepare the Surface Properly

Tiles stick to flat, clean, stable surfaces. They do not stick well to dusty, flaky, or uneven walls. Before tiling:

• Plasterboard: Seal with a coat of diluted PVA (1 part PVA to 5 parts water) and let it dry. This reduces suction so the adhesive does not dry too fast.
• Existing tiles: You can tile over old tiles if they are firmly bonded. Rough them up with 80-grit sandpaper and use a flexible adhesive.
• Painted walls: Sand the surface to create a key. Scrape off any flaking paint.
• Floors: Ensure the subfloor is rigid. Flexible floors cause grout to crack. Use tile backer boards on timber floors for a solid base.

Tip 2: Plan Your Layout Before You Start

Dry-lay tiles along the longest wall to plan your layout. The goal is to avoid narrow slivers at the edges — anything less than half a tile width looks amateurish and is harder to cut cleanly.

Measure the wall or floor width, divide by tile width plus spacer gap, and adjust your starting point so the cuts at each end are equal and generous. Mark a centre line with a spirit level and chalk line.

For bathroom walls, start from the bottom of the second row up (rest the first row on a temporary batten) so your top row meets the ceiling with a full or near-full tile.

Tip 3: Choose the Right Adhesive

This is where many beginners go wrong. Not all adhesives are the same:

Adhesive Type	Use Case	Approx. Cost (per 20 kg)
Standard ready-mixed	Small wall tiles, dry areas	EUR 10–15
Flexible powder adhesive	Floors, underfloor heating, large tiles	EUR 15–25
Rapid-set powder	When you need to grout the same day	EUR 18–28
Waterproof adhesive	Showers, wet rooms	EUR 20–30

For floor tiles or tiles larger than 30 x 30 cm, always use a flexible powder adhesive. Ready-mixed adhesives lack the strength for heavy tiles and are not suitable for floors.

Tip 4: Use the Right Trowel Notch Size

The notch size on your adhesive trowel determines how much adhesive sits behind the tile. Too little and tiles pop off; too much and adhesive squeezes through the grout lines.

• 6 mm notch: wall tiles up to 20 x 25 cm
• 10 mm notch: floor tiles and wall tiles up to 40 x 40 cm
• 12 mm notch: large format tiles (60 x 60 cm and above)

For large format tiles, also "back-butter" the tile — apply a thin skim of adhesive to the back of the tile as well as the wall or floor. This ensures 100% coverage and prevents hollow spots.

Tip 5: Keep Spacers Consistent

Use plastic tile spacers at every junction. The most common sizes are 2 mm for a minimal grout line, 3 mm for a standard look, and 5 mm for a rustic or industrial style. Whichever you choose, be consistent. Uneven spacing is the most visible sign of amateur tiling.

Push spacers in vertically at the corners so they are easy to remove before grouting. Never leave spacers in place under the grout — they can show through over time.

Tip 6: Grout Like a Professional

Wait at least 24 hours after tiling before grouting (or follow the adhesive manufacturer's instructions). Mix grout to a thick, creamy consistency — it should hold its shape on the float without being stiff.

Work the grout diagonally across the tile lines with a rubber grout float, pressing firmly to fill every gap. After 15–20 minutes, wipe off the excess with a damp (not wet) sponge using diagonal strokes. Let it haze over, then polish with a dry cloth.

For wet areas like showers, use a waterproof or epoxy grout. Standard cement grout absorbs water and can develop mould. Apply silicone sealant (not grout) where tiles meet the bath, shower tray, or worktop — these joints need flexibility.

Tip 7: Cutting Tiles Cleanly

• Straight cuts: A manual tile cutter handles most wall tiles. Score once with firm pressure, then snap.
• Floor tiles and porcelain: Use a wet tile saw for clean, chip-free cuts.
• Curved cuts and holes: Use a tile hole cutter or diamond-tipped drill bit. Mark the hole, start slowly, and keep the bit wet to avoid cracking.

Always wear safety glasses when cutting tiles. Porcelain shards are razor-sharp.

Common Mistakes to Avoid

1. Skipping the layout plan — leads to awkward narrow cuts at edges.
2. Using the wrong adhesive — ready-mixed on floors or with large tiles causes failures.
3. Tiling over an uneven surface — the tiles telegraph every bump.
4. Grouting too early — tiles shift if the adhesive has not fully cured.
5. Not sealing natural stone — porous tiles like travertine and marble stain permanently without a sealant.

Plan Your Tiling Project

Get started with accurate material estimates:

• Tile Calculator — tiles, adhesive, and grout for any room
• Bathroom Tile Calculator — optimised for bathroom layouts
• Kitchen Tile Calculator — backsplash and floor tiling
• Tile Spacing Guide — spacer sizes and grout line widths