How to Clean Shower Tiles and Grout Without Damaging Them

Shower tiles themselves are rarely the problem. Glazed ceramic and porcelain are close to non-porous, so soap scum and hard-water film sit on the surface and wipe off. Grout is different. Standard cement-based grout is porous: it soaks up water, body oils and soap residue, and in a warm, poorly ventilated room it discolours from the joint outward. Knowing which surface you are cleaning — and what it is made of — decides which method is safe.

First, work out what you have

Glazed ceramic or porcelain tiles. The most forgiving surface. Most household bathroom cleaners are fine, as long as you avoid harsh abrasives on high-gloss finishes.

Unglazed porcelain, natural stone or real terrazzo. Marble, limestone, travertine and cement-based terrazzo react with acids and can be scratched by abrasive powders. These need pH-neutral cleaners only.

Cement-based grout. The usual grout in most homes. Porous, stains readily, and is slowly weakened by acidic cleaners.

Epoxy grout. Harder, glossier and far less porous. It resists staining and does not need sealing, but strong solvents can dull it.

Silicone. The flexible bead at internal corners, around the shower base and where tiles meet a bath or screen. It is not grout, and it is cleaned — or replaced — differently.

If you are not sure, water is a quick test: splash the grout and watch. If it darkens within a minute or two, it is unsealed or poorly sealed cement grout.

A weekly routine that prevents most of the work

• Squeegee the walls after showering. Removing standing water is the single biggest thing you can do for grout.
• Run the exhaust fan during the shower and for a good while afterwards, or leave a window open. Grout that dries quickly stays cleaner.
• Wipe once a week with warm water and a pH-neutral cleaner on a microfibre cloth, paying attention to the lower third of the walls and the floor, where soap residue collects.
• Rinse and dry. Leftover cleaner leaves a film that attracts more grime.

How to deep clean dirty grout

Work through these steps in order and stop as soon as the grout comes clean. There is no point using a stronger product than the job needs.

1. Ventilate and protect yourself. Open a window, run the fan and wear rubber gloves. Eye protection is sensible when scrubbing overhead.
2. Rinse the area with warm water to soften surface grime.
3. Scrub with a pH-neutral cleaner and a stiff nylon grout brush or an old toothbrush, working along the joint rather than across it. Never use a wire brush or steel wool: both scratch glazes and can leave rust marks.
4. Try a bicarbonate paste for stubborn discolouration. Mix bicarbonate of soda with a little water to a thick paste, press it into the joints, leave it for ten to fifteen minutes, scrub and rinse. It is mildly abrasive and mildly alkaline, which suits cement grout and glazed tiles.
5. Use an oxygen-based cleaner (sodium percarbonate) for grey or brown grout that the paste did not shift. Mix it in warm water to the label directions, apply, leave for the stated time, scrub and rinse. It is generally gentler on coloured grout than chlorine bleach, but test a small hidden patch first.
6. Rinse thoroughly with clean water and wipe the tiles dry. Residue left in the joints keeps working on the grout and attracts dirt.

A steam cleaner can help lift grime from porcelain and sound grout, but it can loosen grout that is already cracked or crumbling and it is hard on old silicone. Keep the nozzle moving and avoid it on natural stone unless the stone supplier says otherwise.

Soap scum and hard-water marks on tiles

The white film on glazed tiles is usually a mix of soap residue and minerals from the water. A pH-neutral cleaner removes fresh film. For heavier build-up on glazed ceramic or porcelain, a diluted white vinegar solution or a mild acidic bathroom cleaner will dissolve it — but apply it to the tile face with a cloth, keep contact with the grout brief, and rinse the whole area straight away with plenty of water.

Do not use acidic products on natural stone, on real terrazzo, or on grout you are trying to preserve. Repeated acid cleaning is one of the main reasons cement grout becomes sandy and recessed over the years.

What never to mix

This is the part that matters most for your health:

• Never mix chlorine bleach with ammonia. It produces toxic chloramine gas. Some glass and multipurpose cleaners contain ammonia.
• Never mix chlorine bleach with acids — vinegar, lemon juice, or acidic toilet, rust or scum removers. It releases chlorine gas.
• Never combine different cleaning products in the same bucket or on the same surface at the same time. Rinse fully between products and read every label.
• Do not use hydrochloric acid or brick cleaner on bathroom tiles. It is a trade product for specific jobs, it attacks grout and many finishes, and the fumes are dangerous in a small room.

If you feel short of breath, get light-headed or your eyes sting while cleaning, leave the room, get fresh air and let it ventilate before going back in.

Cautions for natural stone and terrazzo

Marble, limestone, travertine and cement-based terrazzo all contain calcium-based material that acids dissolve. Vinegar, lemon and many "scum remover" sprays leave dull, etched marks that cleaning cannot fix — only honing and resealing can. Use a pH-neutral stone cleaner, soft cloths and nylon brushes, and dry the surface after use. Our terrazzo tiles guide covers the difference between real terrazzo and porcelain lookalikes.

Sealing after cleaning

A clean, sealed cement grout joint stays clean much longer. Once the grout is spotless:

1. Let it dry completely. In a shower this usually means not using it for at least a day, and longer in a humid room — follow the sealer's label.
2. Apply a penetrating grout sealer with a small brush or applicator bottle, keeping it to the joints as much as possible.
3. Wipe any excess off the tile face within the time given on the label, before it leaves a haze.
4. Let it cure for the stated time before the shower is used.
5. Check it periodically. If splashed water darkens the grout quickly, it is time to reseal. Showers need it more often than walls outside the wet zone.

Epoxy grout and glazed porcelain do not need sealer. Unglazed porcelain and natural stone often do; check with the tile supplier.

When cleaning will not fix it

Some problems are not dirt. Grout that is cracked, crumbling or missing, tiles that sound hollow when tapped, silicone that has pulled away, or stains and swelling on the other side of the wall point to water getting behind the tiles. Cleaning and sealing will not solve that, and a failed membrane gets worse the longer it is left. Black staining that has grown into silicone also rarely cleans out — the bead needs replacing.

When it is time for more than a clean

If the grout keeps failing, the room may need regrouting, retiling or new waterproofing. Our tiling and wet-area finishes page explains how epoxy grout, falls and sealant joints reduce maintenance, and waterproofing covers the signs of a leaking shower. For rough budgets, see the bathroom renovation cost guide. If you are on the Northern Beaches, we can measure up and quote it.