Short answer
Epoxy grout is made from resin and hardener instead of cement. It's dense, stain-resistant, colour-consistent and never needs sealing. Cement grout is cheaper and easier to install, but it's porous and needs sealing. Epoxy is worth it in showers, kitchen backsplashes, white or light grout, mosaics and commercial kitchens. For most dry floors, a good cement or high-performance grout is fine.
Side by side
| Epoxy grout | Cement grout | |
|---|---|---|
| Stain resistance | Excellent | Fair; better with sealer or high-performance types |
| Sealing | Never | Yes, and resealing over time |
| Colour consistency | Very even; no blotching | Can dry patchy; varies with water and weather |
| Mould and mildew | Resists (non-porous) | Can hold moisture and grow mildew |
| Chemical resistance | High | Lower; acids etch it |
| Installation | Harder: short working time, haze must be cleaned off before it cures | Easier and more forgiving |
| Material cost | Several times higher | Low |
| Labour | Higher | Lower |
Where epoxy is worth it
- Showers: no sealing, and it resists the soap scum and mildew that make shower grout look old.
- Kitchen backsplashes: tomato sauce, oil and coffee wipe off.
- White and light grout: stays the colour you chose.
- Mosaics: lots of grout means lots of surface to stain.
- Commercial kitchens, washrooms and pools: often specified for chemical resistance and hygiene.
Where cement grout is fine
- Living-area and hallway floors with mid-tone grout.
- Large-format tile with very few grout lines.
- Budget-sensitive projects, especially with a modern high-performance cement grout, which narrows the gap.
The installation catch
Epoxy cures quickly and sticks to everything. Any haze left on the tile has to be cleaned off while it's still workable; once it hardens, it's very hard to remove, especially on textured or matte tile. That's why epoxy costs more in labour, and why it should be done by someone who's used it before. Some installers test a spare tile first.
Can you switch to epoxy when regrouting?
Yes. Old cement grout can be removed and replaced with epoxy, provided the old grout is cleaned out deep enough and the joints are clean and dry. See regrouting a shower.
What about corners?
Whichever grout you choose, inside corners and changes of plane get a flexible sealant, not grout. Rigid grout cracks there (see why grout cracks).
