draining rainwater into foul water drains

[Drew21]

Hi, I'm extending my house and as part of this I want to rationalise my guttering and rain water drainage. Currently the rainfall onto the 2nd storey roof drains onto a 1st storey roof terrace. This water (added to the rain falling on the roof terrace) then exits via a gully at the far end of the roof terrace. This means that the 2nd storey roof rainfall must travel all the way across the 1st storey roof terrace on its way to the ground. It always ponds en route though.

The current guttering downpipe from the 2nd storey roof runs very close to the bathroom drains and I would like to be able to join the two together so that the rainwater and foul water would run in a combined drain into the existing foul water drain. I understand that this is not a goer however and I'm keen to understand why as my builder couldn't tell me why.

The situation is complicated by the fact that the foul water drain goes underground on a neighbours land, just the other side of the party wall. Otherwise running a new rainwater drain nearby would be an obvious option. However, as this new drain would need a new gully on my neighbours land I'm trying to avoid that option.

The other way would be to run a long horizontal rainwater drain across the roof terrace.

any ideas?

It's difficult to explain all this in words, let me know if you need a piccie!!

 

[freddiemercurystwin]

You cannot now drain new rainwater into the foul system as Building Regulations will not allow it. That is, any rainwater that does not already drain into the foul. This is because of the increased pressure on our foul drainage system in the UK. You now need to build a soakaway to drain into within your boundary unless you've a handy stream at the end of your garden. Only if you are unable to build a soakaway for some reason or the soil in your area is unsuitable you will then be permitted to drain rainwater into the foul system. Its a pain in the a**s and whether you agree/disagree, it is what it is.

 

[Drew21]

thanks

the other detail I certainly should have mentioned is that I live in a London mews house and the entire plot is built on, so no garden, no possibility of a soakaway (unless we put it under the kitchen!!)

Does that mean that I may be allowed to drain rainwater in the foul, if I can persuade the building inspector that there is no reasonable alternative?

ta

 

[Chukka63]

in this part of the world a soakaway has to be a minimum of 4.5 m from any building

 

[freddiemercurystwin]

Yes, if you have nowhere to locate a soakaway Building Control will allow it.

 

[jerryjacson]

Yes, if you have nowhere to locate a soakaway Building Control will allow it.

yes it is possible building owner will allow for soakaway.it will be better to talk with him.