All advice / Design and finishes
What grout does in a bathroom
Grout fills the joints between tiles. It keeps water from getting behind the tiles, holds the tiles in position, and finishes the look. In a bathroom, grout is exposed to water, steam, soap and cleaning products every day. The type of grout and how it is maintained affects how the bathroom looks and performs over years.
Most people do not think about grout until it starts to discolour or grow mould. By then, the problem is usually the grout type, not the cleaning.
Cement-based grout
Cement grout is the traditional type. It is a mixture of Portland cement, sand and water. It is affordable, easy to work with and available in many colours.
The downside is that cement grout is porous. It absorbs water, soap residue and dirt. Over time, it stains, darkens and can support mould growth. Sealing the grout after installation helps, but the sealant wears off and needs reapplying every one to two years in a shower.
Cement grout is fine for dry areas — splashbacks, floor tiles in a powder room. In a shower recess, it needs more maintenance than the alternative.
Epoxy grout
Epoxy grout is made from epoxy resin and a hardener. It is non-porous, which means it does not absorb water, does not stain and is highly resistant to mould. It does not need sealing.
Epoxy costs more than cement grout and is harder to apply — it sets faster and is less forgiving to work with. Not every tiler is experienced with it. But in a wet area, the long-term performance is significantly better.
Our tiling and finishes guide covers how grout type fits into the broader tile specification. If mould in the shower is a concern, our mould prevention guide covers the full picture.
Grout colour choices
Grout colour changes the entire look of a tiled wall. A matching colour — white grout with white tiles — gives a seamless, clean look where the joints almost disappear. A contrasting colour — dark grout with light tiles — highlights the tile pattern and makes each tile stand out.
In practical terms, lighter grout shows dirt and staining more quickly. Darker grout hides marks but can fade over time. A mid-tone grey is a popular compromise in current Sydney renovations — it complements most tile colours and hides wear better than white.
The grout colour should be chosen at the same time as the tile, not after. Some tile showrooms provide grout colour samples to test against the tile before the final order.
How wide should grout joints be
The tile manufacturer specifies a minimum joint width. Rectified tiles — tiles with precisely cut edges — allow joints as narrow as 1.5 millimetres. Non-rectified tiles typically need 3 to 5 millimetres to account for size variation.
Narrower joints give a cleaner, more modern look. Wider joints suit traditional or rustic tile styles. In a shower, the joint width affects how much grout is exposed to water — narrower is generally better for maintenance.
Our large-format tiles guide covers joint widths for bigger tiles, where getting the joint right is even more important.
Keeping grout clean
For cement grout: wipe the shower walls with a squeegee after each use to remove water before it dries. Clean weekly with a mild bathroom cleaner — avoid bleach-based products, which break down the sealant. Reseal every one to two years.
For epoxy grout: a weekly wipe with a damp cloth is usually enough. Epoxy does not absorb stains, so marks sit on the surface and come off easily. No sealing is needed.
For both types: good ventilation is the best defence. A fan that clears steam from the room stops moisture from sitting on the grout surface for hours.
How ETR specifies grout
The grout type, colour and joint width are confirmed during the selections process, alongside the tiles. Adam Dawood, with over 25 years in tiling, advises on the best grout for the tile, the location and the client's maintenance preference.
Epoxy grout is standard in our shower recesses. Cement grout is used in dry areas where the performance difference is not needed. A free on-site measure anywhere in Sydney is the starting point.
Frequently asked questions
Is epoxy grout worth the extra cost?
In a shower, yes. Epoxy grout does not absorb water, does not stain and does not support mould growth. It costs more upfront but saves on cleaning time, resealing and replacement over the life of the bathroom.
Can I change the grout colour without re-tiling?
Grout colourants and pens can change the appearance of existing cement grout. They sit on the surface and wear off over time. For a permanent change, the old grout is raked out and new grout applied — a labour-intensive process but cheaper than re-tiling.
Why does my white grout turn yellow?
Yellow or brown staining in cement grout is usually caused by mineral deposits from hard water, soap residue or mould growing within the porous grout. Regular sealing and wiping after each shower slows the process. Switching to epoxy grout prevents it.
How long does grout last in a bathroom?
Cement grout in a well-ventilated bathroom lasts 10 to 15 years before it needs replacing. Epoxy grout can last the life of the tiles — 20 to 30 years — because it does not break down from water exposure.
Should I choose grout colour to match or contrast the tiles?
Matching grout gives a seamless, modern look. Contrasting grout highlights the tile pattern and adds visual interest. In a small bathroom, matching grout makes the room feel larger. In a larger room, contrasting grout can add character.