Sewer question

[Sally2000]

I've just moved into a 1950's house, with a view to adding an extension, new bathroom etc to accommodate a growing family.

Looking at the plumbing and lifting manhole covers, it appears that the foul water, surface water and roofs all discharge into a common sewer pipe.
First question: Is that right for this age of house? I had thought separate sewers were required before then.

There are I think four houses on a common sewer that discharges down a single pipe to the road. Two of the houses have had extensions built, rather similar to what I am planning.
Second question: Is there a limit to how many foul water connections and how much additional roof area can be connected to the existing sewer?

Thanks for any advice!

 

[vinn]

There are a bunch of unknown variables in your questions - perhaps your first call should be to enquire of neighbours how they went about building their extensions?

 

[^woody^]

You might have a combined system, but probably not given the age. You'll have to check or contact the water company

You cant put new rainwater discharge into any drains - even if they are separate. It will have to go into the ground unless there is a very good technical reason why you should not, or you use the existing gutters and downpipes - ie extend an existing roof, but not add a new one with its own downpipes.

For your situation you wont be limited by foul water connections

 

[garyo]

Is failing a percolation test normally a good enough technical reason for most BCOs?

 

[oldbutnotdead]

Is failing a percolation test normally a good enough technical reason for most BCOs?

It is up here- local ones who know the ground conditions won't even bother suggesting a soakaway in some bits of the town

 

[Sally2000]

Thank you for your advice!

Looking into the manhole at the back of the house, I can see that the lavatory discharges into this, as does the kitchen drains and the rain gutter from the back roof. So it really does look as if it is a combined sewer. The house was built in 1952.

I haven't had plans drawn up yet, but I'm expecting that the extended roof's gutter will connect to the existing gutter. That's how my neighbours have done it.

The new shower room and lavatory will be downstairs directly under the upstairs bathroom, so I would expect the lavatory to be connected into the existing soil pipe from upstairs.

Does that sound reasonable?

 

[russellsmiler]

I would say that sound absolutely reasonable, bear in mind that the manhole may now not be under your own ownership as not many years ago the water authorities took responsibility for these, ( oh and made us all pay a charge for doing so).

 

[Hugh Jaleak]

If the sewer under your property is shared, (i.e. one or more other properties use it), then its the responsibility of the Water Company, (Thames if you're in London I would think). Good news is they are responsible for it, bad news, they will insist it is adequately protected as part of the building work, and may ask for a CCTV survey to ascertain its condition before you start work. Extra cost to you, but does protect both parties.

Hierarchy for surface water is usually, soakaway, if not suitable, then surface water drain, if not practical then foul drain. The BCO will advise.

 

[Sally2000]

Thanks Hugh.
I've asked the water co for advice - waiting to hear from them.