Grouting wall and floor tiles can be one of the easiest jobs, or one of the most difficult. Whats the difference? Timing and confidence.
Grouting tiles is done in the same way whether they are floor tiles, wall tiles, ceramic tiles, quarry tiles and so on. The grout needs to get into the joints and to fill them thoroughly and completely. It really does not matter how you achieve that as long as the joints are full and you do not scratch the tiles doing it! In the project below we were doing a floor but a wall is done in the same way.
One of the major factors in grouting wall and floor tiles involves laying the tiles in the first place. If you do not allow wide enough joints between the tiles the grout will not get to the bottom of the joint. This makes it very weak and will soon allow water to enter. Unfortunately there is a school of thought that says very narrow joints are best. This is not the case.
For wall tiles we recommend joints of 3mm and for floor tiles, 5mm as can be seen from the image on the left. When laying the tiles it is also important that the adhesive is not allowed to sqeeze up too far into the joint as its almost impossible to chip it out later and if the adhesive is too high it can affect the grout finish and the finish of the tiling.
Mixing the grout is also very important. We always use grout powder which can then be mixed to any consistency rather than a pre-mixed grout which we find to be quite hard work forcing it into the joints. The hardest of all is the ready mixed adhesive and grout in the same tub. Powder grout mixes easily and can be done by hand simply by using a small container and a trowel. We use large quanitities because we tile large areas and it is more efficient for us to mix using a paddle and electric drill.
There is no reason why you cannot mix grout in this way either. You need two clean buckets for grouting tiles, a large one for mixing in and another, smaller one for rinsing sponges in. You can see from the images that a little water is put in the bucket first (it is important that the powder is added to the water and not the other way round. It makes the mixing process a great deal easier) There will be an indication of how much water you need on the manufacturers instructions on the bag of grout powder. It is typically 1.1 - 1.3 litres per 5kg of grout powder.
Slowly tip the powder into the water while stirring the mix. The finished grout should be a creamy consistency much like thick custard (without the lumps!). If there are any lumps they can block a joint and stop mixed grout filling the joint properly so make sure there are no lumps!.
Once the grout is mixed simply trowel a dollop onto the floor. Dont be scared, there will be a mess but it is easy to clean up. Using a grout float (see the tools section below) or a slightly damp decorators sponge (we find this the best and easiest to use), push the grout round the joints making sure they are full. Scrape up as much grout from the tiles as you can so as not to waste too much.
As you are grouting keep an eye on the waste grout on the tiles you have already done and watch it making sure that it does not dry out totally, hardening onto the tiles and then becoming a nightmare to get off. This is where the timing comes in.
Using a clean damp sponge, you should be able to wipe over the tile and joint to clean off the surplus. The grout should be hard enough to require a fairly strong rubbing action. If it is not hard enough the sponge will "drag" the grout out of the joints and if it is too hard you will need to work very hard indeed as mentioned previously! See our project on removing grout for when you have left it too long.
When the whole surface is wiped over, leave it to dry for a while. It looks spotless when you finish with the sponge but as it dries you will see the residue forming on the surface. Wash this off, again rinsing the sponge thoroughly as often as you can.
After two or three washes leave to dry properly and you will be left with a fine "dust" on the surface of the tiles. This can be wiped off with a clean, dry cloth and your floor will be finished.