What Grout Joint Width for Tiles?
The right joint width comes down to format and where the tile is going. As a guide: small wall tiles 2–3 mm, floor tiles 3–5 mm, large formats kept tight at 2–3 mm. Never drop below about 2 mm, though – that minimum joint is what soaks up the tiles' size tolerances. And the wider you go, the more grout you'll get through.
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Guide values for joint width
- Small wall tiles / mosaic: 2–3 mm.
- Standard floor tiles: 3–5 mm.
- Large format / rectified: 2–3 mm.
- Outdoors / terrace: 3–8 mm (to absorb movement).
Formula: Wider joint → higher grout demand (see grout formula)
Example: going from 3 mm to 5 mm joints raises grout demand by about two thirds.
Practical tips
- Rectified (calibrated) tiles allow very narrow joints.
- No joint below ~2 mm – otherwise no tolerance for size deviations.
- Choose joint colour deliberately: dark joints hide dirt.
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Download on the App StoreCommon questions
Can tiles be laid without joints?
No – a minimum joint of about 2 mm is needed to absorb tolerances and movement.