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A guide to tile grout joint widths

It is important to remember that the grout joints are not purely an aesthetic feature, they provide an important technical function. In our latest blog, our team will take you through everything you need to know about the gap sizes between tiles, which are often referred to as either the ‘grout line’ or the ‘grout width’, with the gap required dependant on the type of tile, the substrate, the grout itself and of course, your own personal preference.

These grout lines are designed to prevent water, dust and dirt from accumulating within the gaps between tiles, whilst also ensuring the tiles are able to withstand movement, thermal expansion and any variations within the sizes of the individual tiles. The common installation method involves a gap of 2mm or 3mm for wall tiles and between 3mm and 5mm for floor tiles. However, it is important to follow the standards within the BS 5385-1 which outline the sizes required depending on the tiles being used and the substrate.

Important points to note:

· If you are using rectified tiles, a standard grout width of 2mm or 3mm should be used along each tile edge to create a professional and seamless finish. However, non-rectified tiles often require larger widths of between 3-5mm, as it is important to allow for possible variations in the tile edges.

· Tiles which are installed above wooden substrates are often prone to movement, however this can be minimised through effective grout line widths. By ensuring the correct grout line gaps are used, potential cracking, chipping and de-bonding can be prevented. In addition, flexible grout should be used, as it can help to absorb any movement.

· Tiling directly onto plywood is no longer recommend as a suitable substrate, instead a specially developed tile backer board should be used. These boards provide a stable and moisture resistant surface, with the additional benefit of being more environmentally friendly.

· The facial area of tiles also has a bearing on the required grout width, with smaller tiles measuring less than 600mm in length needing a minimum grout width of 2mm. For larger tiles measuring up to 1200mm in length, a grout width of at least 3mm is required.

Instructions to achieve the ideal grout width:

1) The substrate must be dry, clean and flat, after all a tiled surface will only be as good as the surface below it. To assist, a tile backer board system can be installed to create an ideal tiling surface.

2) Before beginning tiling it is advisable to complete a trial run of the tile layout, with the tiles and required spacers used to help visualise the final design.

3) Use a laser level or chalk line to mark a straight reference point, then lay the first tile in-line with this mark. The adhesive used should be selected based on the surface and the type of tile being used, with a variety of products available to suit every project.

4) Use tile spacers to create the required grout width between the first and second tile, with at least 2 spacers used per tile side. If a levelling system is used, such as the LevTec system, additional spacers may be required to create the ideal grout width, whilst still avoiding lippage. T-shaped spacers are available to use in joints between a tile and a wall or flat surface.

5) Butt the second tile against the spacers of the first tile, then add more spacers ready for the next tile. Continue to repeat this process, with spacers used to establish an accurate grout width across the entire tiled area.

6) It is important to include expansion joints in large tiled areas, otherwise known as movement joints, as these are designed to create space for slight movements within a tiled surface. These joints should be installed around the perimeter and at distances of between 5-8m across the surface.

7) When the tiles have set after between 20-30 minutes, remove the spacers before the adhesive fully dries. This time can vary between adhesive manufacturers, so you will need to check labels to find out accurate drying times.

8) Grout can then be applied between the tile gaps; this bonds the tiles together and creates a waterproof seal.

Navarro Tiles - A wholesale supplier of tiles throughout the UK and Ireland

As a wholesale supplier of tiles, we are committed to providing high-quality products alongside professional guidance and advice. If you would like to discuss grout joint widths in more detail, please contact our knowledgeable team today. Alternatively, if you are searching for your nearest stockist of products mentioned within this article, our sales team will be more than happy to help.

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