I have a horizontal external soil pipe feeding into a vertical stack from the bathroom, with the waste pipes feeding into it. The order from the end of the horizontal soil pipe section running towards the stack are 1. Sink, 2. Bath, 3. Shower, 4. WC. in that order.
I want to move the shower waste from its current position to between the WC waste and the stack. This makes the shower waste pipe run shorter, but I can't work out why it was not done like this previously. So my question: Is there a reason why I should not have a shower waste between the WC and stack? I hope this is clear, if not I can post an image. Thanks in advance.