optimum drop for main foul sewer drain

[hunggaur]

hi folks i have to reply all the main sewer drains in the back or our garden as they are fibre pipe which is collapsing.

however i am not sure they were put in right in first place.

could someone please advise me what the optimum drop on the pipe should be in degrees

many thanks

jon

 

[denso13]

Depends on the diameter but for 110mm it should be 1.43° or 1:40.

 

[hunggaur]

yes it is 110mm

have i understood that right is should be less than a 1.5 degree drop over the entire length 20 + meters ????

cheers

Jon

 

[denso13]

Yes, or 500mm over 20m

 

[Nige F]

hi folks i have to replace all the main sewer drains in the back or our garden as they are fibre pipe which is collapsing.

jon

do You have to do it - have you checked with your sewerage company - some / all might be their responsibility