Drainage

[burts]

I’m a plumber but do very little under ground drainage. My mate wants to relocate an internal stack to external. That parts not an issue, however the drain is about 1.5m below the drain cover/surface level. Can the pipe be channelled in just below surface level and dropped in to the drain or do I have to take the pipe down the 1.5m to flow in to the drain where the existing pipe does?

Thanks

 

[ted456]

If you took the drain to the manhole and dropped 1.5m then i think you are in Back Drop man hole territory - stay out of it.
Why not drop the soil stack to a depth that will allow a slow grade to the man hole invert?
Min cover for a sewage drain is 750mm i think.

 

[frutbunn]

I would avoid a back drop, 1.5m is not really that deep.

Min cover for a sewage drain is 750mm i think

There is no minimum cover, provided the drain is protected.

 

[^woody^]

A back drop still requires the pipe to be fitted vertically and then come in to the manhole at the invert level. You just have a clearing point at high level, not all the crap cascading into the manhole!

Don't forget the proper rest bend, not just a standard 90.

 

[burts]

Decided to just dig down beside the house and connect on to the pipe leading to the drain

Thanks for responses

 

[burts]

Decided to just dig down beside the house and connect on to the pipe leading to the drain

Thanks for responses