Any problems with my proposed drain plan

[marsaday]

I am relaying the drains around my house because i am doing an extension on the back. I am also on a semi set up whereby my drains go to the back of the house and then cross over to my neighbours and run down his drive.

However, i have found out from a camera survey i have my own connection into the road from my front downpipe. Our road is a combined system as well.

ALSO my neighbour has in the past had a conservatory extension and his drains have been altered and actually does a loop into my garden (under my current conservatory and soon to be extension) and then back onto my connection and back under his wall onto his system (very complicated).

So the best option is to redo all this work while i build my extension. I'm doing all the work so it is just the cost of the plastic and my time. I think i can get rid of the muck on the garden.

I have done a plan, but the only way i can show it to you is via another website as i can't load onto this site.

This is the link if you would be kind enough to critique my plans. I think i may need a manhole around the connection next to the pavement and one off the first leg which sits between the neighbour wall and my new extension wall.

https://www.diynot.com/diy/threads/new-drainage-layout.483877/

[seanandruby]

Normally you would do to seperate runs, one for foul and one for sw. About a metre from your drive threshold you would then put in a manhole, with both rubs going in, this is so you have a surcharge on each manhole/ic. You will have to trap every gully for down pipe.

[marsaday]

I understand about the traps on all gullies.

What is SW ?

My system is a combined one. The whole road is on combined.

So no need for two systems.

So i need a manhole at the entrance to the drive.

[seanandruby]

What i was saying is although it is a combined drainage system it is usual to install to seperate runs until you get to the combined manhole. The manhole should be inside your property by a metre. It is connected to a lateral pipe out to the main run. As i said you need to be thinking of the surcharge on manholes/ inspection chambers with foul and sw ( surface water/ storm water) build up at peak times and stormy weather.

[marsaday]

I see, but the current set up is original drains all running into one run, so i am recreating what is already here.

Will building control make me do two runs ?

[msh paving]

round this way our combined system is all into 1 run, never done 2 runs

[seanandruby]

Sorry i thought it was a new set up you were doing. It depends on your building control but if it's existing then you can't be expected to change it. It would be new bulids that would be expected to do 2 seperate runs.

[marsaday]

Spoke to BC, and i just lay one run as currently like this.