Shower waste run

[Mattram65]

Hi, first post so be gentle.

Am renewing my bathroom. Existing bath and basin are connected to the stack on the same pipe run In addition to the bath and basin I am installing a separate shower tray, which will require a 4.6m run with one 90 degree turn. This obviously exceeds the permissible 3m run for 40mm, so am not sure how to overcome this. As the shower run passes under the bath and the basin, is it acceptable run from the shower in 50mm and then T the bath and the basin into the same run?

Thanks for your help.

 

[JPC]

running it in 50mm is fine, but i would not tap in the other 2 as you might get syphoning (when showering the water rushing past the basin "t" pulls out the waste water.

I know its more work but might be worth just running the 50mm out the wall seperatly

 

[leakydave]

You could fit an anti syphon trap on the basin before teeing the two (basin and shower) together. It would admit air instead of losing its seal.