A higher quality tile could allow for a 1 16 or 1 8 grout line and maybe even a brick layout as lippage may not be an issue in a perfect tile world where as a lower quality tile might have major lippage risk so laying the tile in 1 3 s and having a 1 4 grout line is recommended.
Grout joint size for wall tile.
For example if the edge warping of a rectified tile is 1 32 the minimum grout joint is 1 8 1 32 5 32.
We recommend a 3 16 grout size for our ceramic tile line.
Often we see 1mm grout joints between wall tiles and 3mm grout joints between floor tiles.
However for example a 1 5 mm variation in a grout joint between 3 mm and 5 mm would not be noticeable.
The tile council of north america and accompanying tile organizations recommend an average grout joint.
They also suggest adding to this width the amount of edge warping on the longest edge.
Ideally your grout joints would be 1 3mm.
Tcna recommends a minimum 1 8 grout joint for rectified tile and minimum 3 16 grout joint for calibrated tile.
Actual finished grout spaces will vary from 1 8 to 1 4 if 3 16 spacers are used.
If smaller spacers like 1 8 are used it will accentuate the size difference of handmade tile.
Rectified tiles are any man made tile such as porcelain and are specifically designed to have as.
For example grout will discolour over time so keeping the joints smaller will minimse this issue.
All ceramic and stone large format tile greater than 15 requires a minimum 1 16 grout joint according to ansi.
For cementitious grout joints smaller than 1 8 generally should only be grouted with unsanded grout and joints of 1 8 and larger should only be grouted with sanded grout.
Joints larger that 3 8 usually need a more heavily sanded grout to accommodate the large joint.
This thickness leaves room for the natural variation in size and the perfectly imperfect edges of handmade tile.
The wider spacing will help to accommodate placement of tile and maintaining straight lines.
For rectified tiles as as3958 1 gives no guidance to joint size then the manufacturers recommendation should be referred to.
The grout joint size for 12 inch porcelain tiles recommended size.
Not only does it look better to have smaller joints it also can minimise issues.