Maximum drainage pipe fall for rainwater

[phatboy]

So I think, I will probably go for either a steep pipe directly into the main pipe, or a vertical drop and then a 1:40 fall to the main drain.

Would building control be happy with these approaches? As this patio and drainage is part of an extension project they may inspect it.

Dunno why you don’t do the backdrop….. it’s the proper method and will get approved

 

[Peter500]

Dunno why you don’t do the backdrop….. it’s the proper method and will get approved

Maybe I will. I was avoiding that as it will be a lot more money (a whole inspection chamber) and a lot of work (digging down at least 1m deep). I would also probably need to redo an existing pipe with a backdrop as it will probably need a different level for the chamber.

 

[phatboy]

Maybe I will. I was avoiding that as it will be a lot more money (a whole inspection chamber) and a lot of work (digging down at least 1m deep). I would also probably need to redo an existing pipe with a backdrop as it will probably need a different level for the chamber.

I thought you were looking to do an angled pipe into the main chamber? That would be even more digging if so.

A diagram or sketch may help

 

[Peter500]

I thought you were looking to do an angled pipe into the main chamber? That would be even more digging if so.

A diagram or sketch may help

There is no 'main chamber'. My pipe is the end of the run and it goes into a neighbors property, so I currently don't have access to any chambers. It requires me adding a new chamber.


As the ACO drain is quite close to where the existing pipe is, I would need to dig out most of the area for a backdrop. It may save around 1m of digging at the ACO drain end, but as I will have already dug out for the sump unit, there won't be a huge amount to do at that end.