We have a tiled terrace over part of the house and it is leaking to the garage and a room below (mudroom). The area is about 250 square feet. Some of the tiles are cracked and some have deteriorated grout and may have contributed to the leak and maybe fixing the tile and re-grouting would be a fix, but I plan to put new tiles and wanted to know what the proper way to waterproof such an area. I haven't removed any tiles to see what is underneath and don't know the extent of the damage below the tiles. I have heard that you can lay some thick plastic sheets or use hot mop method, but it was not from an expert. When I try to tackle this project myself, I want to be sure I am using the most appropriate waterproofing method to prevent future leaks. Thank you in advance for any advice.