Grouting ceramic wall tiles

The grouting of ceramic wall tiles should be carried out after all the tiles have been fixed and allowed to firm up (this usually means leaving them for at least 24 hours after the last tile has been fixed).

Before applying any grout, make sure that the tile faces and joints are all clean - often when fixing tiles, small amounts of tile adhesive will get on the glaze and squeeze out of the joints - all this needs to be removed before grouting.

Ensure that the correct type of grout is used for where you are using it, i.e. use waterproof grout where necessary.

Grout is available as either premixed or as a powder for mixing with water. Different people have different views on which is better - premixed starts off as the right consistency but begins to 'go off' as soon as the packet is opened, powder grout means you have to have a bit of skill to get the consistency spot-on, and any unused mixed is wasted but the powder will last sometime if stored in a dry place.

If using powder grout, mix some in accordance with the instructions to a smooth lump free consistency; if the mixture is too runny, the grout will run out of the joints before it sets, while if the mixture is too stiff, it will be hard to work it into the joints.

Work over an area of about one square metre (or sq yard) at a time, otherwise you may find that the grout stiffen up before you finish the applying and the sponging. Having said that, you need to keep moving onto new areas of a wall as you work so that the whole wall is completed in one session, if you stop before a wall is completed, joints in the grout may become visible. If you have to stop grouting part way through grouting a wall, clean the joints back so that there is a definite finish line and taper the grout back so that when the grouting is restarted, the new grouting will go over the taper.

Pull a squeegee or grout float (i.e. a float with a flexible edge) loaded with some grout across the face of the tiles with the flexible edge at about 45 degrees to the tile face. Pull the float diagonally across the joints so that the edge does not drop into the joint lines, keep changing the direction of the squeegee so that both the vertical and horizontal joints are filled. Use one of your fingers to fill-in any joint which the squeegee cannot cover.

After all the joints are filled with the grout, clean off the squeegee and holding it at about 90 degrees to the tile face, remove any excess grout by pulling it diagonally across the joints - this will keep the grout in the joints level with the face of the tiles.

Square edged tiles need to grout to be finished flush with the tiled face - tiles with radius edges need the grout to be finished to the bottom of the radius.

Once the grout has hardened off (typically about 10 minutes, but the grout instructions should specify), clean the face of the tiles of surplus grout by lightly wiping a clean, damp sponge across it - keep the sponge reasonably clean by rinsing any excess grout from it.

To achieve the required finish, either:

  • For a grouting finish level with the face of the tiles, repeat the sponging after another five minutes.
  • For a concave joint finish, smooth away the excess grout from the joints by pulling a round finishing tool, or the end of a length of wooden dowel, along the joints.

With a almost dry sponge, clean the surface again - for concave joints, use the finishing tool again over the joints.

Leave the grouted area for about 24 hours and then wash down the tiles with a clean, damp sponge once or twice to remove any last trace of grout residue from the tile surface. When the tile surface has dried off, polish it using a clean, soft dry cloth to remove any remaining fine film of grout.