Do you have grout these for kitchen?
You dont need grout, only peel and stick.
What tool will best cut these tiles?
Cut straight edges: You can use a utility knife to create a crack on the tile surface and then break off follow the crack.
Cut through tiles: Use Dremel, chop saw, jig saw or rotary tools.
Can I put this over an existing kitchen backsplash
Yes, You can use it at the existing backsplash, please make sure the surface is clean and leveled.
Are these easy to remove?
No they are not easy to remove. The double sided tape is extremely adherent. you can heat the tiles with a hair dryer, and then use a tile chisel or scraper to remove it.
Would this work and last in the shower wall?
Our peel and stick backplash tile can be used at shower wall, but please check the wall is clean and smooth.