One topic that often causes some confusion for the home DIY’er is just how big grout lines should be between tiles.

What size should grout lines be?

This is a question you will have to face in the very earliest days of a project, at the point when you are making decisions about the finish and calculating how many tiles you will need to complete the project. Here are some top tips for figuring out how big is big enough.

Mind the gap

Keep in mind that grout lines are just a gap between the tiles. They absorb any irregularities in the edge finishing of tiles.
They allow for expansion and contraction of tiles avoiding stress cracks.
They absorb some of the impact pressure the edges of tiles are exposed to, avoiding chipping
They give a cohesive look to the finished project.

No wrong answer

The thing that may surprise here is that there really is no definitive answer. The size of the grout line may change depending on the material you are working with, the type of space you are working on, and the finished look you are hoping to achieve.

Common practice

Leave a 2-3mm gap between tiles.

Rectified Tiles

Rectified tiles are high quality porcelain tiles that are made with perfectly straight edges and are exactly “square” so there is less need for wide grout lines to iron out irregularities along their edges and in their exact dimensions. This type of porcelain tile can be installed with a very thin grout line less than 3mm and by using with coloured grout to match the tiles gives a seamless contemporary look to walls and floors.

They are also sometimes described as “sharp edge” tiles as the manufacturing process makes their edges very sharp so think about this if you will have outside facing edges as they could be liable to chipping.

Keep the space

Anything with a uniform width can be used for this job. Matchsticks, nails, and loose change have all been used with some degree of success but by far the easiest solution is to use ready-made tile spacers. These are plastic cross-shaped inserts and are designed to be grouted in around tiles. They can be found in a wide range of widths and are perfect for most jobs.