There is no standard for grout joints. According to the TCNA, the grout width can vary depending upon the size of the tile. Many stone and tile manufacturers suggest that grout joints be no less than 1/8″ to 3/16″.Click to see full answer. Similarly, you may ask, how thick can grout lines be?Grout generally comes in a few standard thicknesses, ranging from 3/16″ to 1/16″. Though this may seem like a very small difference, in reality it is very noticeable.Also, what is standard tile spacing? If you want a standard look, tile installers recommend grout lines of 1/16 inch for walls and 1/8 inch for floors. For regular-format tiles, between 12 by 12 and 16 by 16 inches, you can stay with those measurements or go up to 3/16, depending on the tile and the look you want. Keeping this in consideration, how wide should grout be? 1/8 inchHow big should grout lines be for 12×24 tile? Grout line guidelines Regular – 12 X 12 up to 16 X 16 inches square. Large format tile – 18 X 18 inches and larger.