How to Grout Tiles: A Step-by-Step Guide
The short answer
How do you grout tiles?
Wait until the tile adhesive has set, usually 24 hours. Clean out the joints, mix the grout to a thick paste, and press it into the joints with a rubber float held at 45°, sweeping diagonally. When the grout firms up, wipe the tiles with a damp sponge, then buff off the haze. Use silicone, not grout, in corners and where tiles meet the bath, shower base or floor.
Grouting is the easy part of tiling, as long as you work in small areas and get the timing right. Here's each step, how much grout you'll need, and how long it takes to dry.
What you need
- Grout: a standard cement grout for joints up to about 6 mm, a wide-joint grout for wider ones, or epoxy grout (more on that below).
- A rubber grout float, two buckets, a mixing paddle or margin trowel, and a large grout sponge.
- Gloves, a grout rake or old flat screwdriver, a soft dry cloth, and silicone with a caulking gun.
How to grout tiles, step by step
1. Choose your grout colour
A grout close to the tile colour hides the lines and makes a wall look calm. A contrasting grout, like white with dark tiles, shows off the pattern. Try a few on our tiles here, or on our grout colours page.
Pearl with mid grey grout
- What it shows
- A clear outline around every tile, so the brick pattern shows without shouting.
- What it hides
- Most splashes and grime: mid tones are the easiest grout to keep looking clean.
- How it ages
- Ages the most evenly of the five: grime blends in, and it doesn't show a white haze the way black can.
Dark grout on a light glaze: ask your tiler to grout a spare tile first. Some tile makers coat the glaze with a wash-off grout release, so the colour can't settle into it.
See Pearl tilesFull-size sample $7
2. Wait for the adhesive to set
Leave the tiles alone for at least 24 hours after laying, or as long as your adhesive's bag says. Grout too early and you can shift the tiles.
3. Clean out the joints
Pull out any spacers and scrape out adhesive that has squeezed up between the tiles, so the joints are clear to at least two-thirds of the tile's depth. Vacuum the dust out, and wipe the tile faces.
How wide should the joints be? As a rule of thumb, at least 1.5 to 2 mm on walls and at least 3 mm on floors. Keep them the same width all the way through.
4. Mix the grout
Put the water in the bucket first, measured as the bag says, then add the powder and mix to a smooth, thick paste, like toothpaste. Let it stand for about 5 minutes, then stir it again without adding more water. Only mix what you can use in about 20 minutes: some grouts start to stiffen after that.
5. Spread it with the float at 45°
Scoop grout onto the float, hold it at 45° to the tiles and press the grout firmly into the joints, sweeping diagonally across them. Work a small area at a time, about a square metre. Then hold the float upright and scrape the extra off the tile faces, still on the diagonal.
6. Sponge the tiles
Wait until the grout is firm and loses its wet shine, usually 15 to 30 minutes (longer in cool weather or with wide joints). Then wipe the tiles with a damp, well wrung-out sponge in light diagonal strokes, rinsing the sponge often. Too wet a sponge pulls grout out of the joints and weakens it.
7. Buff off the haze
Once the grout has hardened, usually after a few hours, a thin powdery haze is left on the tiles. Buff it off with a soft, dry cloth.
8. Silicone the corners and edges
Grout cracks where surfaces move against each other. Internal corners, the joint where wall tiles meet the floor, and the edges around a bath or shower base get a flexible silicone instead. Run it in a colour that matches your grout.
How much grout do you need?
It depends on the tile size, the joint width and how thick the tile is. Small tiles have far more joints, so they take far more grout. These figures come from our tile calculator, with 15% extra for mixing and waste.
| Tile | 1.5 mm joints | 2 mm joints | 3 mm joints |
|---|---|---|---|
| Chroma 52 x 160 mm | 0.70 kg | 0.94 kg | 1.41 kg |
| Chroma 100 x 100 mm | 0.55 kg | 0.74 kg | 1.10 kg |
| Subway 75 x 300 mm | 0.40 kg | 0.54 kg | 0.80 kg |
| 300 x 600 mm | 0.16 kg | 0.21 kg | 0.31 kg |
| Brescia Earth 600 x 600 mm | 0.11 kg | 0.15 kg | 0.23 kg |
| Brescia Iconic 600 x 1200 mm | 0.09 kg | 0.11 kg | 0.17 kg |
So a 2.5 x 2 m bathroom tiled to the ceiling in 52 x 160 mm wall tiles, about 20 m² of wall at 2 mm joints, takes about 19 kg of grout: one 20 kg bag. Its 600 x 600 mm floor takes about 1 kg.
How long does grout take to dry?
About 24 hours for most cement grouts, and longer when it's cold. Most can take light foot traffic within 3 to 24 hours, but wait 4 to 5 days before you use a new shower. If you're sealing cement grout, seal it after 3 to 7 days, once it has fully cured. Epoxy grout can be walked on after 12 to 24 hours and is ready for full use after 2 to 4 days. Times vary by product, so check the bag.
Cement or epoxy grout?
Cement grout is cheap, easy to work and fine for most walls and floors. Epoxy grout resists stains far better and doesn't need sealing, so it suits showers, kitchen benches and pools. But it often costs three to five times as much a kilo, and it has to be cleaned off before it sets, so it's harder for a first-timer to get right.
How to regrout tiles
If old grout is cracked or stained for good, rake it out with a grout rake or an oscillating multi-tool with a grout blade, at least 2 to 3 mm deep, taking care not to chip the tiles. Vacuum the joints, then grout them as above. If it's just dirty, try cleaning it first: see how to clean grout.
Regrouting won't fix a leaking shower, grout that keeps cracking, or tiles that sound hollow when tapped. Those point to a problem behind the tiles, so get a tiler to look.
Common grouting mistakes
- Grouting before the adhesive has set. Tiles shift and joints crack.
- Too much water in the mix. Weak grout that cracks, goes patchy in colour or leaves a white bloom.
- Sponging too soon, or with a wet sponge. It washes grout out of the joints. Leave it too late and the haze is hard to shift.
- Working too big an area. The grout sets on the tiles before you sponge it.
- Grout in corners and edges. It cracks. Use silicone there.
- Grouting porous stone unsealed. Grout can stain natural stone and other porous tiles, so seal them first.
Grouting tiles: common questions
How long do you leave grout before wiping it off?
Until it's firm and loses its wet shine, usually 15 to 30 minutes. Wipe too early and you pull grout out of the joints; too late and the haze is hard to shift.
Can you grout over old grout?
Not straight over it. Rake the old grout out first, at least 2 to 3 mm deep, then regrout. Even grouts made for topping up need at least 1 mm of space.
How long does grout take to dry?
About 24 hours for most cement grouts, longer in the cold. Most take light foot traffic within 3 to 24 hours, but wait 4 to 5 days before using a new shower. Check your grout's bag.
How much grout do I need per m²?
It depends on the tile. Our 600 x 600 mm floor tiles take about 0.23 kg a m² at 3 mm joints, and our 52 x 160 mm wall tiles about 0.94 kg at 2 mm. Our tile calculator works it out for any tile.
Should I seal grout?
It's optional, but sealing cement grout helps it resist stains on floors and splashbacks. Seal it once it has fully cured, after 3 to 7 days. Epoxy grout doesn't need sealing.
