Combining basin & shower waste to exit into existing hop

[Blou]

Hi,

Just created a new ensuite next to existing bathroom. But because of sloping roof, basin and shower enclosure have to sit opposite outside wall.
My only option is to use a reducer 32/40 (basin to shower), then combine waste pipes underneath the shower tray and then run this outside into the existing old hopper, which also takes the waste from the existing bathroom.

Are there any regs that I need to be aware of or any ways to combat trap seal loss if any?

Any advice would be useful as my brain is beginning to hurt!!

Have included pic (hopefully) showing grey line of proposed waste run.

Grey line showing waste direction?

• Blou
• 18 Jun 2009
• 1

 

[clf-gas]

Run all the pipe in inch and half, then at the point you come up for the basin waste use inch and half to inch and a quarter reducer in the elbow.