Standards for Grout What is the standard for determining the size of a grout joint?
We are often asked what is the standard for determining the size of a grout joint – can it be bigger or smaller – does it need to be a specific size, etc. There is a relevant standard on page 33 of the ANSI A108/A118/A136.1 manual. You will see that it is not specific – however this is the only part of the standard addressing joint spacing. ANSI A108.02, Section 4.3.8 – Nominal centerline of all joints should be straight and of even width with due allowances for hand-molded or rustic tiles. In general there is not a specific standard for the size of a grout joint. However, there are many relevant parameters that should be considered. 1) What is the amount of variation from tile to tile? 2) Are the edges of the tile linear or irregular (e.g. “hand-molded”)? 3) How big is the tile? 4) What is the surface of the tile; can it be easily scratched? 5) Where is the tile being used? 6) Is the surface level? Ultimately, the project owner should choose the grout joint they desire, keeping in min
