Currently in the middle of a bathroom refit. Just had first-fix plumbing done and new flooring installed and plumber has sent me some photos of the pipework before flooring went down (see attached).
The shower and sink waste combine into one before crossing the joists to get to the soil pipe. From the photo the plumber sent me, it looks like there must be a fall from the shower waste down to the sink waste (it's pieces of rigid pipework joined with a straight connector, so can't possibly be falling from both ends, right?). Also, I'm not sure why a T-piece that should be used vertically has been used horizontally? Anyway, my logical conclusion is that water will be permanently sat in the section of pipe between the T-piece and where it turns to go up to the sink. So, if I'm right, that leads to a few questions:
The shower and sink waste combine into one before crossing the joists to get to the soil pipe. From the photo the plumber sent me, it looks like there must be a fall from the shower waste down to the sink waste (it's pieces of rigid pipework joined with a straight connector, so can't possibly be falling from both ends, right?). Also, I'm not sure why a T-piece that should be used vertically has been used horizontally? Anyway, my logical conclusion is that water will be permanently sat in the section of pipe between the T-piece and where it turns to go up to the sink. So, if I'm right, that leads to a few questions:
- Is this going to pose a major problem or will the waste coming from the sink just displace the water in the pipe as it would be coming from a higher source?
- Will this set-up result in the sink draining too slowly and backing up?
- Is there a risk the sink waste could get into the shower tray (esp. with the strange T-piece that's been used, meaning the water will need to do a sharp left-turn)?
- How about the water coming from the shower while showering? Will it all flow via the T-piece down to the soil pipe, or is there a chance it will push water back up the sink waste?