Hi, all I need some advice please on a sanifo. When installing a waste pipe of a freestanding bath in an upstairs room. Can I put the waste pipe from the free-standing bath under the floor and then cume up onto the floor lever. (This will be like a trap) then go along the floor and onto a sink then onto the bottom inlet on the sanifo. will it cause a problem with emptying the bath thanks? Looking forward to your replies.