Have had ongoing problems with leaks in ensuite shower. Decided to do a once and for all "fix it" got new tray with upstand and new door. Wall needed to be built out a couple of inches to fit tray and door. However the builder has installed the tray without using the upstand with the effect that there is a little u shape between where the tiles and shower tray meet and this has been siliconed. The door has not yet been fitted. To do the job right it all has to come down again and the job started from scratch including building out the wall. The builder is insisting that all will be well and that he will guarantee for 10 years - I don't believe he would ever come back. I don't want a discount I want the job done again. Am I being unreasonable? What rights do I have? thanks