I have a concrete side walk and porch on the front of my house and was thinking of stamped concrete, pavers and then thought what if i layed flagstone over the side walk and then filled the cracks in with concrete. could I glue the flagstone with constriction adhesive, and would I have a problem with water getting under neath and cracking the flagstone. was just trying to find way to mack the side walk look better with out spending alot of money. Its very stained and old looking. any help would be great. Another Question is how to build a flagstone mail box. Do you build the inside with cinder block and then glue the flagstone to the block then fill in crack with concrete?