We just bought a house that has a tiled terrace on part of the garage and covering a lower level mudroom. Some of the tiles are cracked and the grout has deteriorated in some areas. I plan to re-tile the terrace when the weather warms up a little bit but wanted to find out what is the proper water proofing methods for such an area. I don't know what's under the tiles, but whatever it is, there must be some damage since it is leaking through in some areas. I have heard you can lay plastic or hot mop, but I want to use the most durable and longest lasting material/method to prevent future leaks. Any suggestions would be appreciated. I can post a photo of the terrace if it would be helpful.