shower drainage

Hello. I had a new shower put in last summer and it has never drained properly. It has a shallow tray and overflows easily due to the very slow rate of drainage. I know this is a common problem but none of the usual culprits seem to be causing it. Here are the facts : There was no drainage...

Hi. I'm putting in a shower and re-positioning the hand-wash sink in the bathroom. I'd prefer the fall/down pipe (the vertical run) to run down the inside of an external wall, then about 1 foot above the ground go through the wall to eventually discharge into a drain just below where it comes...