The builder started demolishing the bathroom and shower 07/10/2014 (three weeks ago) and then proceeded to do waterproofing, bedding, tiling etc. As appeared, from the words of tradesmen who worked on the site there was barely any waterproofing originally. This is a question to original sub-contractors and certifiers who did the original work - how that might have happened? Anyway until last week everything went well when I went to check the shower drain and found that the water stays there on one side and doesn't flow out completely. The builders closed it with the grate and were about to finish the whole job, but I pointed that problem to them and said it should be rectified before they finish everything. They started saying that "it's normal and the water will evaporate". Then they started saying that they couldn't do another drain and this is the only possible solution. The whole floor and shower walls were ripped off - why the hell didn't the...