plumber Tom

Those little plastic looking crosses that you can use will create your gap. Any tile grout can be used, but you may want to go with a colored grout. Even pre-mixed tile grout is available. The secret is to let the grout cure before you add a grout sealer. Read the directions. Grout contains portland cement and spashing water on the joints may be recommended for the 1st few days. After the grout has been fully cured and sealed, then you can use a small bead of caulk for added protection.