The finished look of a tiling installation is down to the design and the tiles selected. There are, however, a significant number of grout lines also visible which can affect the final appearance. It is therefore important to grout carefully, getting the best result possible.
Here, Martin Pouncey and Alan Collins, technical training managers at Instarmac, share some tips to follow for perfect grouting every time.
Mix the grout in accordance with the manufacturer’s instructions. It is particularly important not to make the grout too fluid as this will cause separation, resulting in a weaker surface and varying colour – a simple tip but so important.
When mechanically mixing grouts, a drill speed of less than 300RPM with the paddle held beneath the grout surface is ideal. Aggressive mixing can pull air into the product which can show as air holes upon curing.
Be patient and leave the grout to stand for a couple of minutes after mixing. This will allow the reaction of all the product components to begin. We also advise you give the grout a quick stir after a couple of minutes standing.
Do not re-mix the grout after this initial period and do not add extra water to try and retain mobility. If the grout has thickened up too much to apply, then you are best to throw it away and mix a fresh bag.
Once in the joint, the grout should be left to firm before cleaning down. This is to ensure it remains in the joint and does not absorb significant levels of moisture when the area is cleaned.
On a side note, the time to firm is dependent upon several factors. The more porous a tile and/or substrate then the quicker the firming up will happen, for example, ceramic tiles will be able to be cleaned much earlier than porcelain tiles.
Joint width will also play a part, with wider joints taking longer to firm. Finally, ambient conditions will also have an effect. Cold and damp environments with poor ventilation will result in the grout taking longer to firm.
When cleaning, do not over apply water. We advise using a sponge or squeegee. If using a ‘washboy’ it is important to drain the sponge thoroughly otherwise this can reintroduce a significant amount of water into the grout, causing separation and surface patchiness when curing.
You can also the UltraTile ProClean range for even easier cleaning and grout removal. g