Low profile shower tray and pipe depth and fall

[andytw]

I am looking to install a low profile shower tray onto an existing concrete downstairs floor. I understand that the trap will be 'in the ground' and that the waste will need to be chased into the floor. Just looking to understand what might be typical requirements as the final exit point through the external wall is critical. The drains at this end of the site are just below ground level, i.e. top of pipe is almost visible and ground level is 200mm below bathroom floor level.
Length of run is c. 2500mm

Questions then :-
What depth would the top of the pipe be when connected to the trap ?
What is the minimum, but effective, fall I can use on the waste ?

andytw

 

[Madrab]

1. Depends on type of trap you're using
2. 40mm pipe would need at least 18mm over 3m

 

[muggles]

Absolute minimum fall is 18mm per metre but I'd still expect that to block with hair from time to time, especially if you have bends in the run. Recommended fall is 44mm per metre

 

[dilalio]

Could you put a small inspection pit outside so you can rod it if it blocks?

 

[andytw]

Could you put a small inspection pit outside so you can rod it if it blocks?

View attachment 95788

Thanks, but was going to have an elbow with access point as it exits the wall, then discharging into a gulley, space permitting.