How to choose tile grout: CG1, CG2, flexible or epoxy
October 25, 2026
Grout fills the joints between tiles. A good grout keeps water and dirt out, stays the same colour and does not crack. The standard EN 13888 gives every grout a class code — here is what it means.
Grout classes
- CG1 — normal cement grout, for dry interior walls and floors with light use.
- CG2 — improved cement grout, with extra properties:
- W — reduced water absorption: for bathrooms, showers, kitchens and balconies.
- A — high abrasion resistance: for floors that are walked on a lot.
- RG — reaction resin grout (epoxy): almost waterproof and stain resistant, for kitchens, restaurants, swimming pools and anywhere hygiene matters.
Joint width
Every grout lists the joint width it is made for, for example 1–6 mm or 2–20 mm. Rectified porcelain tiles are usually laid with narrow joints (2–3 mm). Rustic tiles and outdoor paving need wider joints. Choose a grout whose range includes your joint.
Which grout where
- Living areas, dry walls: CG2 or CG1.
- Bathrooms, showers, kitchens: CG2 W (or CG2 WA on floors).
- Outdoor, balconies, heated floors: flexible CG2 WA.
- Kitchen worktops, restaurants, pools: epoxy RG.
Choosing the colour
A grout close to the tile colour makes the surface look calm and larger. A contrasting grout shows off the tile pattern. On floors, mid-grey hides dirt better than pure white.
See our tile grouts — every product page shows its class, joint width, colours and data sheet.
Questions
When can I grout after tiling?
Usually after 24 hours with a normal adhesive, and after a few hours with a fast-setting one. The adhesive data sheet gives the exact time.
Is cement grout waterproof?
A CG2 W grout absorbs little water and is fine for showers. For full waterproofing, a waterproofing membrane goes under the tiles; the grout alone is not a waterproof layer.
