Grout starts life crisp and pale and ends up… not. Kitchen and bathroom floor grout absorbs grease, soap scum and general life until the whole floor looks tired no matter how much you mop. When people ask what is the best way to clean grout between floor tiles, they’ve usually tried bleach and a toothbrush and given up halfway.

I’ve restored grout in two kitchens and a bathroom — including one floor I was convinced needed retiling — and the right method makes an astonishing difference. Here’s what works, ranked by effort and effectiveness, plus how to keep it clean afterwards.

What is the best way to clean grout between floor tiles? Ranked methods

Start with the gentlest effective method: a paste of bicarbonate of soda and water, applied to the grout lines, left for 10 minutes, then scrubbed with a stiff grout brush (not a toothbrush — a proper narrow stiff brush, £5, saves your knees and your sanity). For most moderately dirty grout this is enough, and it’s cheap and fume-free. Work in small sections, wipe clean with a damp microfibre cloth, and don’t flood the floor — excess water just drives dirt deeper.

For stubborn staining, step up to oxygen bleach (sodium percarbonate — the active ingredient in OxiClean-type products): dissolve in hot water, mop onto the grout, leave 15–20 minutes, scrub and rinse. It’s dramatically more effective than chlorine bleach on organic staining and doesn’t produce harsh fumes. The nuclear option is steam: a steam cleaner with a grout nozzle blasts dirt out of porous grout like nothing else — hiring one for a day (£30–£40) is worth it for a whole floor. What I’d skip: neat bleach (whitens temporarily, damages grout long-term) and vinegar on natural stone tiles (the acid etches stone).

  • Bicarbonate paste + stiff grout brush — start here
  • Oxygen bleach solution — best for stubborn organic staining
  • Steam cleaner — the nuclear option, hire for a day
  • Grout pen — cosmetic refresh for small areas
  • Skip: neat bleach, vinegar on stone, wire brushes

The tools and technique that matter

Technique beats products. Always vacuum or sweep first — scrubbing loose grit into grout just grinds it in. Apply your cleaner to the grout lines specifically, not the whole floor; a washing-up bottle with a nozzle or an old squeezy sauce bottle gives precision. Scrub along the grout line, not across it, with firm even pressure, and rinse each section before moving on — dried cleaner residue attracts dirt faster than the original grime did.

Knees will be your limiting factor on a floor: get proper knee pads (£15, the best money you’ll spend on this job) and work in 2m² sections with breaks. An old electric toothbrush is brilliant for fiddly areas around the toilet base and under cabinet edges. And manage expectations on colour: grout rarely returns to its original shade after years of staining — if cleaning gets you 80% there, that’s a win, and the sealing step below locks in the improvement.

Sealing: the step everyone skips

Here’s why grout gets dirty again within months: cement grout is porous, and unsealed grout drinks in every spill. Once your grout is clean and fully dry (wait 24–48 hours), seal it. A penetrating grout sealer (£15–£25 a bottle, enough for an average kitchen) soaks in and blocks absorption without changing the appearance — apply with a small brush or applicator bottle along the lines, wipe excess off the tiles immediately, and do two coats. In wet areas like shower floors, this is non-negotiable.

For grout that’s clean-ish but permanently discoloured, consider a grout colourant/sealer in one — products like Universeal or similar paint the grout a uniform colour while sealing it. It’s fiddly work (mask the tile edges or wipe as you go) but transforms floors that cleaning can’t save. Long-term maintenance is then simple: pH-neutral floor cleaner (not bleach-based), prompt wiping of spills, and resealing every 2–3 years. The 30 minutes of sealing saves hours of future scrubbing.

When to regrout instead of clean

Sometimes cleaning isn’t enough — the grout is too far gone. The signs: grout that’s crumbling or powdery (it’s lost its binder — no cleaner restores structure), grout with deep cracks (water gets behind, and cleaning just feeds the damp), permanent staining that survives steam and oxygen bleach (some pigments and dyes bond irreversibly), or grout that’s visibly lower than the tile edges (erosion — it will only get worse). In these cases, regrouting gives a like-new floor for a fraction of retiling.

The DIY method: rake out the old grout with a grout rake or oscillating multi-tool (£30–40 tool that earns its keep) to at least 3mm depth, vacuum the joints thoroughly, and apply new grout with a float, working diagonally. For floors, choose a grout with built-in sealer or add sealer after — and consider epoxy grout in the hardest-working areas (kitchens, hallways): it’s stain-proof, waterproof and never needs sealing, at 3–4x the material cost and a trickier application. A weekend’s regrouting transforms a floor that cleaning couldn’t save — know when to stop scrubbing and start raking.

  • Regrout when: crumbling, cracked, permanently stained, eroded
  • Rake out to 3mm+ depth; vacuum joints before regrouting
  • Epoxy grout for kitchens/hallways — stain-proof, never needs sealing
  • Seal cement grout after curing — non-negotiable on floors
  • Know when to stop cleaning and start regrouting

Grout cleaning, done properly

Bicarbonate paste or oxygen bleach with a proper grout brush, section by section, then seal it while it’s clean. The cleaning takes an afternoon; the sealing takes an hour and is what makes the result last. Your floor will look years newer by teatime.

If the tiles themselves need attention, tile a bathroom wall for the first time covers tiling a bathroom wall from scratch, and make a small bathroom look bigger has ideas for the wider bathroom refresh. For cleaner and sealer reviews, Which? home improvement guides tests them properly.

The grout lifecycle: clean it well, seal it promptly, maintain it simply — and when it’s truly done, regrout rather than retiling. Grout is the sacrificial layer that protects the tiles; treating it as renewable rather than permanent is the mindset that keeps tiled floors beautiful for decades.