Grouting wall and floor tiles can be one of the easiest jobs, or one of the most difficult. What's the difference? Timing and confidence.
Grouting tiles is done in the same, regardles of 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.
Laying Wall and Floor Tiles
For wall tiles we recommend joints of 3mm and for floor tiles, 5mm as can be seen from the image above.
When laying the tiles it is also important that the adhesive is not allowed to squeeze up too far into the joint as its almost impossible to chip it out later. If the adhesive is too high it can affect the grout finish and the overall finish of the tiling.
Laying wall and floor tiles is a lot easier with our dedicated Tiling Kit that contains all the tools you need to get the job done.
What Tile Grout Should you use?
There are essentially three main types of grout that are commonly used:
- Wall Tile Grout; Usually un-sanded (or non-sanded) grout
- Floor Tile Grout; Sanded grout
- Specialist Grout; Epoxy grout
It is important to get the right type of grout, as this will ensure it lasts as long as possible, in many cases up to the life of the tile. It will also allow getting the grout into the grout lines more easily and then reduce the work that you have to do to keep it maintained.
As the name suggests this is grout that doesn't have sand added to it. This means that it can be pushed into tighter lines a little more easily (wall tiles), but without the sand it will experience more shrinkage which can lead to cracking once dried. This in turn could allow water to penetrate in behind the tile. Because the gap is smaller for wall tiles there is less grout so this shrinkage is not so much of a problem.
People generally do not use un-sanded grout on lines that are greater than 3mm (1/8 of an inch) wide, or even smaller lines, because of the shrinkage that can cause cracking when it is present in larger amounts. This type of grout is generally stickier and can even have added adhesive which makes it ideal for wall tiles due to the extra adhesion that is needed to help get the grout into the lines and enable it to stay there.
This type is generally sold as Wall Tile Groutstrong> specifically designed for use with this type of tile or indeed other tiles with thinner grout lines.
For grouting lines that are wider than 3mm (or 1/8 inch) then a sanded grout should be used. While an un-sanded grout might be easier to get into the joints, there is a danger that this larger thickness and amount of grout will shrink when and as it dries causing cracks. The added sand in the grout stops this shrinkage, and will then be less prone to shrinkage and cracks.
Sanded grouts, as their name suggest, have sanded added to them. This sand can be abrasive and scratch the tile surface while you are applying it so you should always try the grout out on a obscure corner first to see what the effect will be. This will be a potential problem with polished tiles especially, travertine, marble and granite. This type is typically sold as Floor Tile Grout.
These are really specialist grouts that are made from epoxy resins, often consisting of 2 or 3 parts than need to be mixed up and then coloured with a dye.
They can be used in place of either sanded floor tile or unsanded wall tile grout as they do not suffer the same shrinkage issues and because of this, are generally more flexible.
They are also normally water proof; the normal cement based grouts are effectively water resistant which is sufficient for most applications except where water will stand on the tiles, which is pretty rare. Usually this occurs in the shower tray or bath only.
Epoxy grouts are typically much more expensive, and often it is not necessary to pay the extra price. They cure as a result of the chemical reaction that is triggered by mixing the parts together, so you can be under considerable time pressure to get it mixed, applied and any excess cleaned up before it cures fully.
One trick is that you can put half your made up grout into the freezer to slow the chemical curing which will buy you a little more time if you are pushed.
The advantage of using an epoxy type is that they don't generally have any abrasive sands added so they are less likely to cause any damage to any tile surfaces. Again, we do recommend that you test this on an out of the way corner before stating on the whole job.
They also have relatively low levels of maintenance required to keep them clean which is an added benefit.
As you probably understand that classifying the different types of grout into one of these three simple categories is not always easy as there are types that incorporate different features of other grouts that we have described. For example, “universal grouts” usually feature some fine sand added that have some on the characteristics of unsanded and sanded grouts.
You should always read the label and the manufacturer's guidance about where they recommend that their grout should be used.
Additives to Different Types of Grout
Most types now have some additives that help them perform better and help to make them easier to applied. This further blurs the boundaries between the categories that we described above. Here are some of the most common types of additive:
- Mould Killer and Anti-Fungicides: One of the most common issues (normally found in bathrooms) is that over time, mould and other fungus can grow and develop. As it is generally supplied with lots of warm water the grout surface can be a perfect environment for mould growth. By adding a fungicide to the grout this can help reduce the mould growth and prevent the blackening of lines for longer
- Colours: It is possible to get a range of grout colours to match the ties that you are using and the effect you're trying to create
- Adhesives: In some types, compounds that promote adhesion are added, such as PVA. This makes application much easier, particularly if the grout is likely to be used in wall tiles where the extra adhesion is need to work against gravity
- Flexibility and Waterproofing Additives: In some cases, additives can be added to provide extra flexibility if it is to be used on a surface that is likely to have some movement, e.g. if the tiles have been fixed to wood. If they are subject to constant or intermittent immersion, then it is wise to consider a water proofing additive. In both these cases we would suggest adding SBR
Grout Mix for Tiles That will be Immersed in Water
It is a common question that we receive, about how to grout tiles that are going to be immersed in water constantly. Firstly you should consider tanking the area first. A complete run down of this can be seen in our tanking project here.
In this situtation, there are two options available to you; you can either select a waterproof epoxy grout, or you can select an un-sanded grout, which is water proof by nature or if it is not, then you can make it so by mixing in a water proof additive as mentioned above. It is a question of personal preference, but here we will cover the second option (as you should follow the manufacturer's instructions closely when using an epoxy grout).
Take an unsanded wall tiling grout (such as the one pictured above) and then mix it with SBR diluted 1:1 with water. You will then need to leave it at least 24 hours before commencing.
If you are working on a Swimming pool then it should not be filled for at least three weeks after you have finished. Additionally, do not use a grout which the manufacturer states that should not be immersed as no amount of SBR will help here!
Making sure that you use the correct type is essential as this will not only save you problems in application but also maintaining in the years to come.
Mixing your grout up is also very important. We always use the powder-type which can then be mixed to any consistency rather than the pre-mixed type which we find to be quite hard work when it comes to forcing it into the joints.
The hardest of all the pre-mixes is the ready mixed adhesive and grout in the same tub. As it is also an adhesive, it is very sticky and trying to get it to stay in the joints is a nightmare as it just sticks to your fingers, sponge and float and subsequently is pulled straight out as you pass over the surface.
Mixing the Grout
Powder grout mixes easily and can be done by hand, simply by using a small container and a trowel. We use large quantities 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 this way either, if you choose to.
You need two clean buckets - 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 manufacturer's instructions on the bag or container. It is typically 1.1 - 1.3 litres of wtare per 5kg bag of powder.
Slowly tip the powder into the water while stirring the mix. Once finished it should be a creamy consistency much like thick custard (without the lumps!).
On this subject, if there are any lumps they can block a joint and stop mixed grout filling the joint properly so make sure there aren't any!
Top Tip: Where multiple bags are required, always use the same batch number of product to maintain consistency of colour.
It is important to get the right consistency; you need a mix that is workable but not too sloppy. There is no real difference between floor and wall tile grout, but the mix needs to be soft enough to be pushed into any lines without it running back out.
It is often worth allowing your newly created mixed grout to settle for a few minutes before you start applying it – perfect time for a quick cup of tea!
You'll Need the following tools for mixing:
- Plastic builders bucket x 2
- Dust-sheets to cover the mixing area; you don't want to be chipping dried grout off anywhere you don't need it, if you can help it
- Water hose or an adequate supply of water
- Mixing equipment - a Gauging trowel or paddle mixer depending on the amount you have to mix
- Grout powder - Either Floor Tile Grout for floors or either Wall Tile Grout for walls
- Any additives; See above, but you might need additives to colour or to change the properties e.g. water proofing
Top Tip: Do not attempt to grout while tile adhesive is still wet.
Getting the Grout into the Tile Joints
Once your mix is complete, simply trowel a dollop onto the floor (if you are grouting wall tiles, use a sponge to scoop some from your bucket and spread it on the wall). Don't 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 and into the joints making sure they are full. Scrape up as much excess from the tiles as you can so as not to waste too much.
Top Tip: Always carry out a test patch for compatibility prior to full application.
Removing Grout from Tiles
As you are working, 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. At this point it 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! If you do find it's gone hard, 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 a residue forming on the surface. Wash this off, again rinsing the sponge thoroughly as often as you can between passes.
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 once done, your floor or wall will be finished!
You can go over the grout lines with a scraper before it has dried to tidy them up. You are looking for cracks which you need to smooth out with a long movement down the joint. At this stage you can press in any grout that might be thin and sponge off the excess. This will leave your joints looking much tidier and neater.
Top Tip: Check the weather forecast and do not apply grout externally when rain is expected (at least within 6-8 hours of application, but preferably longer).
Sealing Your Grout and the Grout Lines
Generally you should not need to seal your grout after application. Nowadays most grouts will tend to have fungicides added which suppress mould growth and have other additives to make the grout more water proof.
If you have used epoxy grout, then there is no need to seal it as this is waterproof anyway and the sealer will not add anything. If you have added an additive to the grout to make it water proof, such as SBR, then again, there is no need to seal it.
If it is a cement based then you can seal it if you so desire, but it is not really necessary. The grout will repel water anyway so it is not required.