First time posting all my other questions have been answered by looking through the posts thanks very much. But this problem I couldn't find a direct answer for maybe i was using the wrong terminology. This is a crack between the flagstone and the tile it doesn't go all the way around so hopefully I can stop it before it does. None of the flagstone or tiles seem to be loose so is there some caulk I can use to fill the crack and what kind and any tips to make it easier? Pretty good at repairing stuff or i'm to stupid to realize I shouldn't be doing some things.Thanks for any help.