Grout Cleaning in the UAE: How to Clean Grout, and When Cleaning Is Not the Answer

Most dirty grout comes clean with three things: a stiff nylon brush, an oxygen-bleach or baking-soda paste, and patience — then a penetrating grout sealer once it is dry, so it stays clean for longer. Skip the vinegar: cement grout is cement, and acid slowly dissolves it. Cleaning stops being the answer when the black comes back within days (the mould is inside the grout, not on it), when the grout is cracked, crumbling or missing, or when the black line is the silicone at the shower tray rather than the grout. Then the honest options are regrouting, which is a tiler’s job, or getting rid of the grout lines altogether with a seamless surface such as microcement laid over the existing tiles.

We do not clean or regrout tiles — we apply seamless finishes. This guide is here because “grout cleaning” is one of the most common bathroom searches in the UAE, and the honest answer is that most grout needs a brush, not a renovation.

How do you clean grout? The method that works

The short answer: wet it, apply a paste, wait, brush across the line, rinse, dry. In more detail:

1. Wet the grout with warm water first. Dry grout soaks up the cleaner and the dirt with it; wet grout keeps both on the surface.
2. Apply a paste along the lines. For everyday grey grout, baking soda mixed with a little water is enough. For dark or mouldy grout, use an oxygen-bleach powder (sodium percarbonate, sold as an oxygen stain remover) mixed with warm water — it lifts organic staining and mould and is kind to coloured grout.
3. Leave it for 10–15 minutes. The waiting does most of the work. Do not let it dry out on the wall in a hot bathroom; mist it if needed.
4. Brush across the joint, not along it. A stiff nylon grout brush or an old toothbrush. Wire brushes and scouring pads scratch the tile glaze and dig out the grout.
5. Rinse with clean water and dry the surface. Leaving dirty rinse water in the joints just redeposits what you lifted.
6. Seal it once it is completely dry — usually the next day (see below).

A steam cleaner with a narrow nozzle also works well on sound grout between ceramic or porcelain tiles, and it needs no chemicals. On grout that is already cracked or powdery, steam and hard brushing will take more of it out — which tells you something too.

What not to use on grout

Use	Avoid	Why
Baking soda paste	Vinegar, lemon, limescale removers on cement grout	Acid dissolves cement; repeated use erodes the joint and leaves it rougher, so it stains faster
Oxygen bleach (sodium percarbonate)	Chlorine bleach mixed with anything	Bleach plus ammonia or acid releases toxic gas; on its own it can also fade coloured grout
Nylon grout brush, toothbrush	Wire brushes, scouring pads	They scratch the tile glaze and pull grout out of the joint
pH-neutral cleaner for weekly cleaning	Strong acids on marble or natural-stone tiles	Acid etches the stone itself, not only the grout
Penetrating grout sealer after cleaning	Sealing over dirty or damp grout	You lock the stain in under the sealer

A note on limescale. UAE tap water is hard, and in showers the white crust on tiles and grout is mineral, not dirt. The products sold to dissolve it are acidic — which is exactly why they are hard on cement grout. Use them sparingly, rinse straight away, and never leave them to soak into the joints. Squeegeeing the shower walls after use prevents most of the build-up in the first place.

Why does grout turn black in UAE bathrooms?

Grout turns black because it is porous cement that stays damp: soap residue and skin oils feed mould, and the moisture lets it grow into the joint. UAE homes add three things that make it worse:

• Bathrooms without windows. Many apartment bathrooms rely only on an extract fan. If the fan is weak, switched off, or only runs while the light is on, the room never dries out between showers.
• Air conditioning against humid air. Cool surfaces in a humid bathroom collect condensation, and grout is where it lingers.
• Hard water. Mineral deposits roughen the grout surface and give dirt and mould somewhere to hold on.

Two quick checks before you scrub:

• Is it the grout or the silicone? The black line where the wall meets the shower tray, bath or basin is usually silicone sealant, not grout. Mould grows into silicone and cannot be scrubbed out — the fix is to cut it out, dry the joint and re-seal with a fresh bead. No grout cleaner will change it.
• Does it come back within days? If cleaned grout turns grey-black again within a week, the mould is living inside the joint or behind it. Cleaning removes what you can see; it cannot reach what is growing below. That is the moment to stop cleaning and look at the options below.

How to keep grout clean after you have cleaned it

Seal it, ventilate the room, and wipe weekly with a pH-neutral cleaner. Cement grout takes a penetrating sealer: it soaks in and makes the joint shed water and soap instead of absorbing them. Apply it to clean, completely dry grout with a small brush or applicator bottle, wipe any excess off the tiles before it dries, and keep the shower dry for the time on the label. You will know it needs renewing when water stops beading on the joint and starts darkening it — in a busy family shower that comes sooner than in a guest bathroom.

Epoxy grout is different: it is a resin, not cement, so it does not absorb water and does not need sealing. If you are regrouting a shower, it is worth asking your tiler about it.

Then the habits: run the extract fan during and for a good while after every shower, squeegee the walls, and leave the door open when the room is not in use. Ventilation does more for grout than any cleaner.

When grout cannot be saved: regrout or go grout-free

If the grout is cracked, crumbling, missing in places, or stains again within days of a deep clean, cleaning has reached its limit. The honest options, from smallest to largest:

Option	What it fixes	What it does not fix	Who does it	Price
Deep clean and seal	Surface dirt, light mould, soap film	Mould inside the joint, cracked or missing grout	You	Cost of a brush and a sealer
Grout colourant pen	The look of stained but sound grout	Anything under the colour; it wears in wet areas	You	Low — a retail product
Regrout with cement grout	Cracked, crumbling or deeply mouldy grout	The grid itself — it will need sealing and cleaning again	A tiler	Priced by the tiler
Regrout with epoxy grout	The same, plus far better stain and water resistance	Loose or hollow tiles underneath	A tiler	Priced by the tiler
Microcement over the tiles	Removes every grout line on floors and walls	Hollow, loose or leaking tiles — those must be fixed or removed first	RBS	Floors from AED 250/m², walls from AED 220/m², wet zones from AED 350/m²
New tiles	Everything, including a failed tile bed	— the new grout needs the same care	A tiler	Priced by the tiler

We do not regrout, re-tile or supply tiles. If the tiles themselves are fine and you like them, regrouting with epoxy grout by a good tiler is usually the most sensible money you can spend — and we will tell you so.

Is there a bathroom with no grout to clean?

Yes. A seamless finish removes the grout lines altogether: microcement laid over the existing tiles, or tadelakt, the burnished lime plaster. Neither has joints for mould to settle in, which is the main reason people choose them for showers.

Microcement over tiles. It goes over sound, well-bonded tiles at about 2–3 mm, with no demolition. The glaze is ground so the base coats can grip, hollow tiles are re-fixed first, and the grout lines are filled by the base coats over a reinforcing mesh so the grid cannot show through later — the full checks are in can microcement go over tiles. In a shower it must be the full wet-zone system: a waterproofing membrane, the microcement coats and an immersion-grade sealer, from AED 350/m², supplied and installed. Floors are from AED 250/m² and walls from AED 220/m², with no mobilization fee. Our microcement bathroom page shows how the wet-zone build-up is laid.

What it does not do. Microcement is not maintenance-free: the sealer is what you look after, with a pH-neutral cleaner and no acids, bleach or abrasive powders — the routine is in how to clean microcement. It cannot fix a tile bed that is failing: if the tiles sound hollow across whole areas, or the old shower has leaked, they have to come out first. And it is a finish for homes and normal-use rooms — not for heavy-use floors such as busy commercial kitchens or anything trolleys cross. Nor is it a weekend project: the grinding, mesh and sealing are trade work, and can you DIY microcement explains where a DIY microcement kit over tiles goes wrong.

Tadelakt. A lime plaster polished with stone and soap, the traditional hammam finish. It is warmer and softer-looking than microcement and fully seamless, but it asks more of you: nothing acidic may ever touch it, so the limescale removers above are out for good. We apply tadelakt in Dubai and across the UAE; it is priced per project after a site visit. The trade-off is laid out in tadelakt vs microcement for a bathroom.

Which one should you choose?

• The grout is grey or has surface mould, and it is sound: deep clean it with oxygen bleach, seal it, and fix the ventilation. This is most bathrooms.
• The black line is at the shower tray or bath: replace the silicone. The grout may be fine.
• The grout is cracked, crumbling or stains again within days: call a tiler to regrout — epoxy grout in the shower if the budget allows.
• The tiles are sound but you are tired of grout, or of the tiles themselves: microcement over the tiles removes every joint without demolition. Ask for a site visit before you decide; the tiles have to pass the tap test.
• The tiles are hollow, loose, or the shower has leaked: neither cleaning nor a coating fixes that. The tiles come out and the waterproofing is redone first.

If you are weighing a grout-free bathroom, send us a photo of the walls and floor and the rough size on WhatsApp, or call +971 4 587 7086. We have worked on UAE homes for 8+ years, with crews trained in-house for microcement and tadelakt, and if your grout only needs a good scrub, we will say so.

Related guides

• Bathroom Walls Without Tiles: Grout-Free Options UAE
• Microcement vs Tiles: Which for a UAE Bathroom?
• Is Microcement Waterproof? Bathrooms, Showers & Pools
• Flooring Options for UAE Homes: An Honest Comparison

FAQ

What is the best thing to clean grout with?

For most grout, a paste of oxygen-bleach powder (sodium percarbonate) and warm water, left for 10–15 minutes and scrubbed across the joint with a stiff nylon brush. Baking soda works for lighter dirt. Rinse, dry, and seal the grout once it is completely dry.

Does vinegar damage grout?

Over time, yes. Cement grout is dissolved by acid, so regular cleaning with vinegar, lemon or limescale removers roughens and erodes the joint — which then stains faster. Use a pH-neutral cleaner for routine cleaning and keep acids for occasional limescale spots, rinsed off straight away.

How do I get black mould out of shower grout?

Apply an oxygen-bleach paste, wait, scrub and rinse, then dry the room well and seal the grout. If the black comes back within a week, the mould is inside the grout or behind it and needs regrouting. If the black is in the silicone at the tray or bath, the silicone has to be cut out and replaced — it cannot be cleaned.

Should I seal grout after cleaning it?

Yes, if it is cement grout. A penetrating grout sealer on clean, completely dry grout makes it shed water and soap instead of soaking them up. Renew it when water stops beading on the joints. Epoxy grout does not need sealing.

Can I steam clean grout?

Yes, on sound grout between ceramic or porcelain tiles — a narrow nozzle lifts dirt without chemicals. Avoid it on grout that is already cracked or powdery, which steam will loosen further.

Is regrouting better than cleaning?

Only when cleaning has stopped working: cracked, crumbling or missing grout, or mould that returns within days. Sound grout is better cleaned and sealed. Regrouting is a tiler’s job; epoxy grout lasts best in showers.

Can microcement go over tiles to get rid of grout lines?

Yes, if the tiles are sound and well bonded. The glaze is ground, hollow tiles are re-fixed, and the grout lines are filled by the base coats over a reinforcing mesh so they cannot show through. In a shower it needs the full wet-zone system, from AED 350/m². It is not a fix for loose tiles or a leaking shower.