Domakihub How to Regrout Bathroom Tiles and Make Them Look New
Restore tired, cracked, or mouldy grout lines yourself in a weekend — no specialist tools needed.
Reviewed by Domakihub home & decor pros · 2026-06-23 · 5 min read
Grout lines take a beating in every bathroom — humidity, soap scum, and years of cleaning eventually leave them stained, cracked, or crumbling. The video above walks through the full re-grouting process visually, while this guide lays out each step with the details you need to plan the job correctly. Whether you manage a private home, a holiday rental in the Cyclades, or a boutique hotel in Athens, refreshed grout is one of the highest-impact, lowest-cost maintenance tasks you can do.
Why Grout Fails and When to Act
Grout is a cement- or epoxy-based filler, not an adhesive. Over time it absorbs moisture, develops micro-cracks from thermal movement, and builds up mould that no amount of scrubbing will permanently remove. In Greek coastal climates the salt air and seasonal humidity cycles accelerate this process.
Act as soon as you see dark staining that bleach cannot shift, visible cracks wider than a hair, or grout that crumbles when you press it. Waiting allows water to reach the substrate behind the tiles, turning a one-day cosmetic job into a costly waterproofing repair.
Tools and Materials to Gather First
You need: a grout saw or oscillating multi-tool with a grout-removal blade, a stiff brush, grout float, sponge, bucket, protective eyewear, and rubber gloves. For materials, choose a pre-mixed or powder grout matched to your joint width — unsanded grout for joints under 3 mm, sanded for wider joints. Pick up a tile and grout sealer for the finish coat.
In Greece, large DIY chains (Praktiker, Leroy Merlin) stock all of this. Budget around one to two hours of labour per square metre for the removal stage if the old grout is hard.
Steps to Regrout Bathroom Tiles
- 1
Remove the old grout
Work a grout saw or oscillating tool along each joint to a depth of roughly 3–4 mm — enough to expose a clean bonding surface without touching the tile edges. Move slowly and hold the tool at a low angle to avoid chipping glazed tiles. Vacuum or brush out all loose dust before moving on. Skipping thorough removal is the number-one reason new grout fails within months.
- 2
Clean and dry the surface completely
Spray the exposed joints with a household mould-killer or diluted bleach solution, scrub with a stiff brush, and rinse thoroughly. Any remaining mould spores will bleed through new grout over time. Allow the entire tiled surface to dry for at least 24 hours — longer in humid coastal areas. Test by pressing kitchen paper into a joint; it should come away completely dry.
- 3
Mix or prepare your grout
If using powder grout, add water gradually to a clean bucket and mix to a smooth, lump-free paste roughly the consistency of peanut butter. Pre-mixed grout can be used straight from the tub. Only prepare as much as you can apply in 20–30 minutes; grout begins to stiffen quickly, especially in a warm Greek summer bathroom.
- 4
Apply grout with a float
Load the rubber grout float and press grout diagonally across the joints in firm sweeping strokes, working in sections of around half a square metre at a time. Push the float at a 45-degree angle to the joints to pack the material in fully and avoid pulling it back out. Once a section is filled, scrape excess grout off the tile faces with the float held nearly flat.
- 5
Clean, finish, and seal
Wait 15–20 minutes for the grout to firm slightly, then wring out a damp (not wet) sponge and wipe the tiles in circular motions to remove the haze. Rinse the sponge frequently and change the water often — dirty water smears grout back onto the surface. Allow 24 hours before light use and 48–72 hours before exposing joints to full moisture. Once fully cured (check the product label, usually 7–28 days), apply a penetrating grout sealer to resist future staining.
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FAQ
- Can I apply new grout on top of old grout without removing it?
- No. Applying new grout over old grout almost always fails within weeks because the new layer has nothing solid to bond to and is too thin to cure properly. Always remove at least 3–4 mm of the existing grout before you start.
- How long does regrouting a standard bathroom take?
- A typical 5–6 m² bathroom takes most DIYers about half a day to regrout: one to two hours for removal and cleaning, then another hour or two for mixing and applying. Add a full drying day before the space is back in use, so plan for a two-day window.
- What colour grout should I choose?
- Lighter grouts (white, cream, pale grey) show mould and staining more quickly but look bright when freshly sealed. Mid-tones like charcoal or warm grey hide wear better and suit the Mediterranean palette common in Greek homes and rentals. Epoxy-based grout in any colour resists staining and mould far longer than cement grout, making it worth the higher cost in shower enclosures.