Marble Tile Grout Size

You never want tiles in direct contact with one another.
Marble tile grout size. Fill grout joints on natural marble with joints larger than 1 8 inch with sanded grout. Finished grout lines will vary from 1 16 to 3 16. Rectified tiles are perfectly uniform with precisely defined edges requiring the least amount of grout. That s assuming the tiles are indeed perfect in size.
If smaller spacers like 1 8 are used it will accentuate the size difference of handmade tile. You can space marble tiles on a fireplace as wide as 1 8 inch apart or as narrow as 1 32 inch. Tiles that vary in size and shape need large grout joint widths 3 8 to 1 2 inch. Spacing the tiles the spaces between your tiles should be no more than 1 8 inch wide a 1 16 inch space is better if the edges of your tiles are straight enough to accommodate it.
Joints wider than 1 8 inch can result in cracked grout and joints narrower than 1 32 inch might. Generally sanded and unsanded grout should never be mixed and absolutely never with marble or any other surface that can be scratched by the sand in grout note. 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. Actual finished grout spaces will vary from 1 8 to 1 4 if 3 16 spacers are used.
We recommend a 3 16 grout size for our ceramic tile line. For the size of the tiles you are using the minimum grout line width for the 12 wall tile is generally 1 16 and for the 24 floor tile 1 8. Marble is a cut product manufactured to extremely tight tolerances and usually designed to be installed with 1 16 spacing. All other cuts of tile from tumbled to chiseled to punched contain slight variations in shape and size.
This will create a smooth slab like surface out of the flat tops of the marble tile. Marble flooring installed in different sized repeating patterns such as the versailles pattern require large grout line widths. Apply the grout in the same fashion with the tip of the float and let the grout begin to harden before. Large grout joints will require the use of sanded grout.
Note that using the smallest grout possible will increase installation time. Literally zero variation in size and all perfectly rectangular.