Which Trowel Notch for Which Tile?
The trowel notch sets how thick the adhesive bed goes down – and with it, whether the tile beds fully or sits on ridges with gaps underneath. Roughly by format: small tiles 4–6 mm, medium floor tiles 8 mm, large formats 10–12 mm. A bigger notch means better coverage, but also more adhesive off the sack.
Download on the App Store
Guide values for the notch
- Mosaic / small wall tiles: 4 mm.
- Wall tiles up to 20 × 25 cm: 6 mm.
- Floor tiles 30 × 30 to 30 × 60 cm: 8 mm.
- Large floor tiles / porcelain: 10 mm.
- Large formats from 60 × 60 cm: 12 mm (often back-buttering).
Formula: Adhesive coverage (kg/m²) ≈ notch (mm) × 1.5
Example: 8 mm notch → about 12 kg/m² – for 20 m² roughly 240 kg.
Practical tips
- Aim for high coverage (contact area) – near 100% outdoors / large format.
- Uneven substrate: larger notch or level the substrate.
- Hold the trowel at 45–60° for even ridges.
Automatic with TileWright
Live calculation as you type, multiple sub-areas, a waste assistant and a visual room designer – fully offline.
Download on the App StoreCommon questions
What is back-buttering (floating-buttering)?
Adhesive is applied to both the substrate and the tile back – needed for large formats and outdoors.