Question about a shared water supply pipe

[fruitpicker15]

My semi-detached house is on a shared water supply with the neighbour and to fix the leaking stopcock on my side I dug part of it up and at the same time figured out the route it takes to next door.

It's a lead pipe and a metre deep as you'd expect. It runs about 8m from the road and T's off to my kitchen then continues along the side of the house, turns the corner and runs across the back of the house before doubling back to the neighbour's kitchen. In all it's another 15m from my kitchen to theirs.

About half a metre down you hit solid blue clay which is difficult to dig even with a pickaxe and a spade wont go through it.

My question is why did the builders (in 1929) do this and use more pipe and labour than necessary? Why not lay two short individual supply pipes on separate connections? Or why not T it off in the front garden instead of doubling back around the side of the house?

I haven't been able to find any answers on this and it has been bugging me because I'm sure builders tried to keep costs down even in those days. Just hoping some people with building/plumbing experience might know.

 

[Last Plumber]

I've not seen this but there are a few thoughts that come to mind.

First off, I would say that when the site was built, (back when all this was nowt but fields), there would of course be plots marked out but no buildings or even foundations?
The ground would be being dug all over for footings, cables, drains, water pipes etc. Therefore it would be a lot more straight forward than you trying to dig at the side of your house or up the drive / garden. It would also be done off drawings of where things are intended to be so there would be no visual thing to avoid or work around as such, (no walls, pathways etc).

One Obvious reason why we see unexplained diversions in old lead pipes are for things which existed at some point in the past but there is no longer any evidence of above ground. Such as the outside toilet.

I don't know if your house was built with an outside loo. It depends on the area and it's wealth in 1929 I suppose. But a lot were.

I hope this helps ?

 

[oz-plumber]

Things like this still happen today - and I am guilty of it.

We were doing a job for an 'owner builder' ( Haven't worked for one since )
We were called to connect the water to the house from the new water meter location. The shortest most direct route was 4 metres. The trench my apprentice at the time dug was 14 metres.
Ths was due to rubbish piles, crates of roof tiles and pallets of bricks blocking the shortest route.
There was no way we were going to spend hours upon hours clearing a path for the shortest route, so we traversed around all the obstacles and connected the water supply to the house.

If I can find the photo's I'll post them.

 

[Chuck]

Just hoping some people with building/plumbing experience might know.

Pure speculation on my part, but the local water board probably charged a per-connection fee and this could have been high enough to make what you've found the cheapest option at the time.

 

[justlead1]

Water is a crucial part of construction and may well have been the first excavation on site to provide a supply for the site. This could also account for the shared supply, as has been mentioned a saving on new supply tapping on main. At the time built a cold supply to kitchen sink and a WC were the need. A one pipe arrangements would be sufficient for the two properties. Some water authorities were offering relaying lead communication and supply pipes with MDPE for a very small charge. With the use of a compressed air boring plant the disturbance of gardens etc is small. It could be worth checking out.
Good Luck

 

[fruitpicker15]

Thanks for your insight everyone. So it seems the reason for a shared supply was to save connection fees. The builder put up 20 houses here so assuming the fee was similair in relative terms to today's fee then it makes a lot of sense to have 10 instead of 20 connections.

As for obstacles that's a good point which got me thinking. As you see in the photo the foundations are simply bricks laid side by side on the clay (nothing else underneath them). That means there would have been stacks of bricks and sand etc on site right from the beginning and the front garden would have been the easiest place.

I also think they laid the pipe after the foundations because the section of brickwork above the pipe (below ground level) was a mess, like the bricks had been knocked out and put back without mortar. I've rebuilt that section and repointed the rest.

You can see why I thought there was a leak but the guys who did the leak test said it must be ground water. It has been this level since the summer so who knows. I'm uncomfortable with it being right up to the foundation and I thought of building a sump with a float switch but if this is its natural level then drying out the clay could cause more problems. There was a leaking sewer pipe which I replaced 6 months ago. The old clay pipe had a T off the main one for the outside toilet which was removed 10 years after the house was built but they hacked off the pipe and left it open ¬.¬

Now I know none of the pipes are leaking I suppose all I can do is fill it in again and hope for the best. The walls in the kitchen are dry but there is rising damp on the party wall on the other side of the house (no pipes under the house afaik) so maybe that's another investigation.