V&A metro tiles with grey grout

How to grout tiles - A user guide for grouting wall and floor tiles

We have been asked by several customers recently about grouting tiles, so thought we would write a short blog on grout and grouting. We hope you find our beginner’s guide useful!

What is grout?

Grout is the material and grouting is the process of filling the joints in between tiles and preventing moisture and dirt getting behind the tiles and keeping tiles in place. It is normally a cement based powder that is mixed with water. Not all grouts can be used for the same application. There are some manufacturers that do a one tub solution of adhesive and grout! (One of our fitters will be trialling this soon and posting a blog in due course) For small areas, this could be a great product! Luckily, most manufacturers clearly label on the front of the packaging what application their grout is suitable for or have a customer service team to advise.

These are some of the things to consider when choosing grout:

  •  What is size of the gaps between tiles?
  • The type of tiles. Are they glass tiles, natural stone, glazed tiles, ceramic tiles, porcelain tiles or crackle glazed tiles?
  • Where the tiles are located – For instance - Power shower enclosure, bathroom or wet-room?
  • Colour options. What best compliments the tiles?
  • Does the grout need to be waterproof?
  • What tools do I need to apply grout?
  • What surface and backing have the tiles been fixed to? Is the backing prone to movement? Is it solid or flexible?
  • Do the manufacturers offer any guarantee on their products?

Tools that are essential and make life much easier are:

  • A rubber grout float with handle.
  • A grout sponge (one for each different colour grout)
  • New large bucket.
  • New smaller tub to mix.
  • Small trowel

These tools are all reasonably priced. Don’t be tempted to use a normal car type sponge! Grout sponges are firmer and don’t fall apart! The grouting float makes application easier as it pushes the grout in to the gap with less effort and the resulting ‘swipe’ already gives a smooth finish. You will need a clean bucket with cold, clean water.

Manufacturers will specify what size gap the grout is suitable for. For smaller gaps, say 1-3mm, the grouts are normally finer in substance, so as to easily be pushed in to the gap.  For larger gaps, the grout is usually courser and contains more sand making it grittier. You need to consider if the tiles have been fixed to a flexible or solid surface. This is very important and if you don’t know you need to find out. Again, there are plenty of grouts on the market that are flexible and can be used in fairly large gaps and so research and advice is essential. For instance, on a tiled bathroom floor that has wooden floor joists and floorboards and even if there has been installed a thin layer of ply wood, it would still be advisable to use a flexible grout.

Some grouts are mildew resistant and are even anti-fungal and anti-bacterial.

Most companies now offer grouts that are waterproof and are suitable for power shower areas or wet-rooms. It is essential to check as not all of them are. Please get in touch, we are happy to advise you.  If you have inadvertently used the wrong grout, you may be able to help remedy the situation by using a grout water-proofer. It is best to try and get it right first time though!

So, what about applying the grout?

We suggest you look at a few, ‘how to’ videos to get a better idea before you start and then suggest the following:

  • Ensure that enough time has passed for the tile adhesive to set and dry. Each adhesive varies so check the instructions.
  • Make sure all tile spacers and all traces of tile adhesive have been removed and each tile has a clean and smooth edge around the joints.
  • A tiled floor normally traps a lot of dirt and dust and therefore a very thorough hoover is advised.
  • It is not advised to wash a tiled floor or wall before grouting as even the slightest moisture can affect application.
  • Put a small amount of clean water in a medium sized tub and add some grout powder, get used to how much water is needed before mixing a large amount. It can take a few seconds for the mixture to absorb. The consistency should not be too loose nor too hard and should not fall off the grout paddle when you scoop it up. It should be easy to push in to the joints.
  • Trial a small area and wipe off with the grout sponge after a few minutes, before the grout fully sets. This is the difficult part and practice will help. Too soon and you will risk dragging the grout out. Too long and you risk having to scrub hard and in both scenarios you will end up with an undesirable finish. Therefore, small area first and build up confidence. You must remember that when you dunk the sponge in the water, it needs to have all of the water fully squeezed out. The sponge should be damp enough to wipe effectively but not have water dripping out.
  • After a few more minutes you will be able to wash over with a clean sponge again. Again, fully wring out the sponge and change water as often as you can. The cleaner the water the better.
  • Once the residue has come off you can leave the tiles for longer and should then buff off any excess to a glorious finish!
  • Finally, look at the manufacturers advice on how long to leave to dry before using if, for instance, in a shower enclosure.
Other things to consider:
  • Natural stone, polished porcelain, crackle glaze tiles and travertine for instance, will need sealing before grouting. This is because they are porous. Some tile fixers will seal tiles before fixing as it avoids any unnecessary staining especially water marks if being wet-cut or adhesive staining and will then stop any moisture ingress. Some fixers seal once before fixing and once or more before grouting. Some will even seal again after grouting. It is essential that you obtain the correct sealant for your specific tile and again we can help advise on this and also have products under ‘ancillaries’ on our website: https://www.littletilecompany.co.uk/collections/sealants 

Thank you for reading!

The Little Tile Company Team




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