Wc pans Positioned back to back

Dobedo · Sep 15, 2020

Hi I’m doing up a cottage. By rearranging a couple of walls upstairs I can replan the bathroom (making it smaller) and include an en-suite to one of the bedrooms. But to achieve this means that In plan the wc pans will be essentially back to back with a wall between. I can position one of the wcs so that its spaced 2-300mm off the dividing wall. is it possible for the wastes from the wcs to use the same waste pipe via a double branch of some sort or do the wastes have to be offset in some way? Thanks

Peter The Master Plumber · Sep 15, 2020

Dobedo said:
Hi I’m doing up a cottage. By rearranging a couple of walls upstairs I can replan the bathroom (making it smaller) and include an en-suite to one of the bedrooms. But to achieve this means that In plan the wc pans will be essentially back to back with a wall between. I can position one of the wcs so that its spaced 2-300mm off the dividing wall. is it possible for the wastes from the wcs to use the same waste pipe via a double branch of some sort or do the wastes have to be offset in some way? Thanks

Avoid a double branch I have had to change this configuration on a job as when the cistern is flushed it will fill the pan you will need to offset the connections have a look the attachment, page 18 shows how to do so it works.

Last Plumber · Sep 15, 2020

If you tee them together (back to back), you will undoubtedly send solid matter from one WC to the other. You need to stagger the connection.

Ben-gee · Sep 15, 2020

You can get a pan connector with a non return flap, for rodent control.

But as Last Plumber says above, it is far better to stagger them if at all possible.

Jim Goodenough · Sep 15, 2020

Ben-gee said:
You can get a pan connector with a non return flap, for rodent control.

But as Last Plumber says above, it is far better to stagger them if at all possible.

Anti Cross-Flow and Rodent Barrier Valve - https://mcalpineplumbing.com/wc-connectors/wc-connector-accessories/arb-1-anti-cross-flow-and-rodent-barrier-valve is a good product, however as already stated better to stagger if you can.

Dobedo · Sep 16, 2020

Thanks for all your comments and help I thought it may be a problem, all much appreciated. I’ll have to offset the wastes in some way otherwise it looks like poo ping pong would result.