Ive just sealed my shower tray with creeping crack which was recommended on site somewhere and it appears to have worked. Theres about 5 cracks some as long as 10 inch and after showers water was soaking the carpet just outside the toilet, an afternoon of cleaning the tray and applying creeping crack every half hour about 5 or 6 six times infact and all seems well carpet is now dry and im chuffed. Not sure how long it will last but if you have a crack this stuff should sort it.