Cracked, stained bathroom grout — do I re-grout or re-tile, and is epoxy grout worth it?

Question

My bathroom grout is cracked, stained and mouldy in places. I can't tell whether I need re-grouting or a full re-tile, and I keep hearing "epoxy grout" is better. - How do I know which I need — when is re-grouting enough vs when do the tiles have to come up? - Is epoxy grout actually worth the extra? - How do I fix it properly, not just patch it? Trying to sort it once rather than keep scrubbing mouldy grout. What's the right call?

Tarek H. · Accepted Answer

Short answer: if the TILES are sound (well-stuck, not hollow or cracked) and only the GROUT has failed, you re-grout — rake out the old grout and re-grout, no need to re-tile. You must re-tile when the tiles themselves are the problem: hollow/drummy (debonding), cracked, lifting, or if there's a waterproofing failure behind them. And yes — in a wet area, EPOXY grout is usually worth the extra: it's waterproof, stain- and mould-resistant, and doesn't crack/wash out like ordinary cement grout, so you're not back scrubbing it in two years.

How to tell which you need: - Re-grout (tiles are fine): tiles are firmly stuck (tap them — solid sound, not hollow), not cracked, just the grout is cracked/stained/mouldy. → Rake out and re-grout. Cheaper, quicker, and fixes most "ugly grout" cases. - Re-tile (tiles are the problem): tiles sound hollow/drummy when tapped (debonding), are cracked or lifting, or the grout keeps failing because water's getting behind and the waterproofing under the tiles has failed. → tiles come up, waterproofing is redone, re-tile. This is the bigger job but it's the real fix when the substrate's gone. - The tell: grout that keeps cracking/going mouldy fast after a proper re-grout usually means movement or water behind the tiles — i.e. it's not really a grout problem.

Is epoxy grout worth it? - In wet areas (showers, bathroom floors) — usually yes. Epoxy grout is waterproof, stain- and mould-resistant, and hard-wearing; it doesn't absorb water or wash out like cement grout, so far less of the mould/scrubbing you're dealing with. - The trade-offs: it costs more and is harder/trickier to apply (needs someone who's done it, and it sets fast), so it's only as good as the installer. - For dry areas it's overkill; for a mouldy shower it's the upgrade that stops the recurring problem.

Common mistake: grouting over hollow/cracked tiles or a failed waterproofing layer — it just cracks again. Check the tiles are sound first. Get a waterproofing and tiling contractor to check whether it's a grout job or a tiles-up job. Anyone switched a mouldy shower to epoxy and stopped the scrubbing?

Lina K. · Answer

We went epoxy in the shower after years of cement grout going mouldy and cracking, and it's been transformative — no more pink/black mould in the joints, wipes clean. It does cost more and our tiler said it's fussier to work with (sets fast, has to be cleaned off properly), so it's worth using someone experienced. But for a wet area it's the fix that actually lasts. In dry rooms we kept normal grout; no need for the premium there. Tap-testing the tiles first is smart — no point grouting over ones that are drumming.

Nadia F. · Answer

The hollow-tile check is the bit I'd have skipped — I'd have just re-grouted and been annoyed when it cracked again. Good to know that recurring grout failure often means the tiles or the waterproofing behind them, not the grout itself. And the epoxy-in-wet-areas advice is helpful; the mould in shower grout is exactly my problem, so paying a bit more for grout that doesn't harbour it sounds worth it. Will get someone to tap-test before deciding re-grout vs tiles-up.

Cracked, stained bathroom grout — do I re-grout or re-tile, and is epoxy grout worth it?

3 answers

People also asked

More in Tile & Ceramic Service