If you ask a tiler, they're going to tell you that the tile job is only as good as whats under it. Any chance the kool deck can detach or "peel" from the base? If so this could pose an issue. Is the slab stable.... meaning any cracks? Are there expansion joints between the slabs? Hopefully so, and you'll want to maintain those. This site is a great tiling forum, but they probably won't know what kool deck is, so be prepared to show pictures or explain the product:
http://www.johnbridge.com/vbulletin/index.php?
Kevin
Bookmarks