I'm a security installer/service engineer and was short of work last year so when my mate asked me if I wanted to refurb her bathroom I gave it a go. I've done this kind of work before but to minimise downtime, I decided to leave the tiling and plumbing to others so I asked another mate's plumber son to bend pipe. Unfortunately, this lad doesn't know left from right and I had to get him to correct the bath taps and I had to fix a leak on the sink waste myself. Anyway, I finished the job (which looked stunning, BTW) and asked my mate if she'd let me 'christen' the shower by way of a test run. Half an hour later and I still can't get the temp to stabilise, conceding that he's got the H&C mixed up. I could have wept. The pipes and valve are sunk in the wall and tiled over and the tray is concreted in. Then I had an idea. The feed pipes rise through a void in the kitchen so it was possible to transpose them. This would sort out the shower but would mean the sink and bath would need to be swapped over. Much easier than digging out the shower valve. Yessss! I rang the lad and told him what he'd done and letting the enormity of it sink in and making him grovel before giving him my solution. I warned him to remember to swap the pipe to the cistern so it filled from the cold pipe. He went back to site to sort it but I then got a phone call from my mate to say there was steam coming out of the toilet when it was flushed. D'OH! Back he went. Luckily my mate saw the funny side, loves her new bathroom and we are still good friends. With hindsight, I should have done it all myself. The tiler went AWOL for days at a time and held up the job. Live and learn.