ᐅ Joint Width for Natural Stone Slabs – What Works?

Hello everyone,

We want to install our natural stone floor (60x120cm (24x48 inches), 2cm (0.8 inches) thick, "Ceppo di Gre" on underfloor heating) with the narrowest possible grout joints. What grout width would you recommend, and what has been your experience?

When researching online, the recommendations vary between 1mm and 3mm (0.04 to 0.12 inches). Is 1mm technically feasible, or would that be unwise?

Thanks and best regards,

Frank

In theory, you can have them installed with grout joints as narrow as two millimeters (0.08 inches). However, this often fails due to the installer and the plates not being measured with millimeter precision. A more realistic joint width is around 4 millimeters (0.16 inches), as we painfully discovered.

Great, thanks for the quick response @Schorsch_baut!