Tile Grout Guide: Colour, Joint Width and Which Grout to Use Where
Grout is the cheapest part of a tiling job and the part everyone notices. This guide covers joint widths for rectified Italian porcelain, how grout colour changes the look of each tile family we stock, and when epoxy is worth the extra work.
Joint widths for rectified porcelain
Our rectified tiles are cut square after firing, so they can be laid at 2mm on walls and 3mm on floors. Never go below 2mm — grout needs a physical key, and a hairline joint will crack as the floor moves.
Non-rectified ceramic, metro and handmade-look tiles need 3–5mm to absorb the size variation between tiles. Outdoor 20mm paving is laid at 5mm and grouted with a wide-joint exterior grout.
Choosing grout colour by tile family
Marble effect: match the grout to the tile background, not the veining. A warm white against Carrara or Calacatta keeps the slab reading as one surface.
Wood effect: use a mid-tone grout one shade darker than the plank so joints read as board lines rather than white stripes.
Metro tiles: this is where grout does the design work — light grey for a soft contemporary wall, charcoal for the classic factory look.
Terrazzo and patterned tiles: pick up the lightest chip colour so the pattern stays continuous across the floor.
Cement vs epoxy grout
Cement-based grout with a polymer additive is right for the vast majority of jobs — walls, floors, bathrooms and kitchens — and is far easier to work and to repair.
Epoxy grout is worth the extra cost in shower floors, steam rooms, commercial kitchens and around wine or oil splash zones. It does not absorb stains and never needs sealing, but it sets fast and is unforgiving to clean off textured tile faces.
Sealing and aftercare
Glazed porcelain and ceramic never need sealing — only the grout does, and only if it is cement-based. Seal after 7 days of curing, then annually in wet areas.
Clean with a pH-neutral cleaner. Bleach and acidic bathroom sprays strip grout sealer and, over time, etch cement grout out of the joint.
Common questions
- Do you sell tile grout?
- No — our tiles ship from Italy, and grout is cheaper and faster to buy from a UK merchant. This guide gives the exact grout type, joint width and colour to ask for.
- What grout joint should I use for rectified porcelain?
- 2mm on walls and 3mm on floors. Anything tighter than 2mm leaves the grout with no key and it will crack out.
- What grout colour goes with marble effect tiles?
- A warm white or light ivory matched to the tile's background tone, so the veining stays the only visible pattern.
- Is epoxy grout necessary in a bathroom?
- Not usually. Polymer-modified cement grout is fine for bathroom walls and floors; epoxy is worth it in a tiled shower tray or wet-room floor where water sits.