Soil pipe routing help

[james Robert]

hi all

Just wondering what the best method would be to route the sink and bath waste in the below photo. I’m thinking about a strap on boss for the sink waste but not sure on the bath waste as the strap on boss would be on the joint of the branch pipe.
Any suggestions would be greatly appreciated.

 

[Hugh Jaleak]

Building regs do not allow any opposing connections into a stack within the area 200mm below the centreline of the WC branch, so as things stand, you're not going to be able to connect the bath without going down through the flat roof.

One option available is to remove the current cast junction, (and the cast pipework above due to the weight), and replace with plastic. Fitting a soil manifold below the junction, in the top of the existing cast would allow a waste connection at that point. Otherwise you are probably looking at a possible rejig of what's already there.

 

[james Robert]

Hi Hugh,

Thanks a lot for your help, I was thinking it might be better to start again in plastic. Just trying to tidy it all up before putting a pitched roof on.

Thanks again, much appreciated,
James

 

[Hugh Jaleak]

If that is the case I'd seriously consider replacing the lot. Cast is hardwearing and has served/continues to serve its purpose, but once it fails (Cracks or starts to leak), best option is to replace. If you're planning additional works, might be better to replace as part of those works.

Having said that, if you can get the required distances on the bath waste, it can be connected via a boss, rather than the manifold, it's your call.