Rising damp / hole in the ground

[Flyfisher]

The potential of accurate digital mapping is certainly powerful but the GIGO* principle can seriously hamper it in practice.

When we had our new mains gas connection laid the gas company duly arrived and dug a hole to expose the services to some nearby houses. They quickly found the yellow ducting (denoting a gas supply) and proceeded to cut it open to expose the actual gas pipe in preparation for joining the new pipe to our house.

Except they found it contained a blue (water) pipe! So, they enlarged the hole a bit more to expose the ducting for the 'water' supply pipe and, yes you've guessed it, they found the yellow gas supply pipe. Perhaps the original installers were colour blind. :roll: I've often wondered if they bothered to report this problem so that the digital mapping data base could be updated.

A similar thing happened when we had our overhead electricity cables replaced with an underground supply. The work itself was very well done and the EDF gang were wonderfully helpful throughout. Then, many months later, an EDF 'overhead lines inspection team' turned up for a routine inspection of the overhead lines still showing on their database!


*GIGO : Garbage In, Garbage Out. The achilles heel of all IT systems.

 

[Penners]

They quickly found the yellow ducting (denoting a gas supply) and proceeded to cut it open to expose the actual gas pipe in preparation for joining the new pipe to our house.

Except they found it contained a blue (water) pipe! So, they enlarged the hole a bit more to expose the ducting for the 'water' supply pipe and, yes you've guessed it, they found the yellow gas supply pipe.

Unbelievable! (Except that, having a Master's Degree in Murphy's Law, I do believe it) :roll:

*GIGO : Garbage In, Garbage Out. The achilles heel of all IT systems.

Not to mention the human brain.

 

[Feltwell]

They quickly found the yellow ducting (denoting a gas supply) and proceeded to cut it open to expose the actual gas pipe in preparation for joining the new pipe to our house.

Except they found it contained a blue (water) pipe! So, they enlarged the hole a bit more to expose the ducting for the 'water' supply pipe and, yes you've guessed it, they found the yellow gas supply pipe.

Unbelievable! (Except that, having a Master's Degree in Murphy's Law, I do believe it) :roll:

It was probably Murphy that put the ducts in. If it's his law then you can't blame him for using it now.

 

[MdB]

My mate is a Civil Engineer and spends a lot of his time digging rather wide trenches suitable for neatly fitting roads into.

He tells us it is not uncommon for him to come across pipes which aren't marked on any maps and typically old enough that it isn't obvious which utility it belongs to. He then calls each utility in turn to confirm with them that it isn't theirs leaving the gas till last. When they say it isn't theirs he puts a hole in the pipe whilst they are on the phone and quite often informs them that it is their pipe and to get someone sent over very quickly due to the large gas leak.

Sounds a silly and dangerous way of operating to me but he says there is no other way of getting the job done.

 

[worms]

to come across pipes which aren't marked on any maps and typically old enough that it isn't obvious which utility it belongs to.

They don't need to be that old. We had the water guys knock on the door to ask if we could remember them putting in a new water supply - they were digging up the road to replace the old asbestos/cement pipes with blue alkathene and found alongside the asbestos/cement a brand new blue alkathene pipe already in place. It wasn't on their maps, they didn't know where it led to and had no way of knowing which, if any, of the properties had been linked into it!

 

[Penners]

They needed a pair of these:

 

[Zebra]

Well then that's obviously the problem, the water isn't in a pipe the way it should be, even I know that and I'm a girl :roll: !

Lady Arowana you may have been right after all - the water's not in the pipe where it should be. Or at least, perhaps Lime's previous assertion that there's still a leak may be right. Or at least, you both got me thinking again. You see, when I said there's no plumbing anywhere near there, there was, straight off the mains, but I capped it off in the ground. The cap isn't leaking, but I never did quite figure out where in the ground that water pipe came in. So today I've dug some more, and found it.
Whilst digging I also found yet another example of the shocking methods of rainwater disposal that the builders in the 60s came up with - a gully on the other side of the porch takes the water from the flat roof, which then runs under the porch, and comes out into a sort of a shallow soakaway, about 20cm from the house! It was completely blocked, but that means all that rainwater is leaking under the slab somewhere. The 1960s porch (which I have permission to demolish and rebuild as the kitchen) also has no foundations, and I could get my forearm under it next to this supposed soakaway! The blighter who did that had the audacity to sign his name on the main beam too, grrrrr.
Anyway, having found this mains pipe, I'd like to cap it off further from the building but it's so badly corroded that there's no way. Could mean a new plastic water main from the road, I fear. Lordy!
I'm newly metered for water, so I suppose I will find out when I get my next bill whether the mains pipes are leaking. If the bill is more than seems reasonable for 17 cups of tea per day and a shower every other Sunday then there must be a leak!

 

[Feltwell]

Anyway, having found this mains pipe, I'd like to cap it off further from the building but it's so badly corroded that there's no way. Could mean a new plastic water main from the road, I fear. Lordy!

How far from the road, and is at all across unpaved garden? If you're lucky you've got a service valve box in the pavement hard up against your boundary.

Installing a new water main feed here to replace our old lead one was easy & quite cheap, but only because we already had the driveway dug up. That's where the expense is - digging the trenches and making good afterwards, if you get someone else to do it. We didn't need the water board to do the work, it's our pipe so it's our responsibility, we could just get on with it. Alkathene pipe with push fit fittings is very easy stuff to use.

 

[Zebra]

Oh really? I can do it myself then? You are helpful you know Feltwell!
It's about 6m, and I have a brand new stopcock thingy in the ground just outside my boundary. The garden will all be dug up anyway - at present it is all raised up to about knee level (the builders dumping rubble I expect?)and I want it all levelled off. I expect I'll get all the digging done when I have the foundations dug out for my replacement extensions. Perhaps it won't be so bad then. In my head I was imagining another huge chunk of expense...

 

[Feltwell]

Well, with Severn Trent there were no problems doing it ourselves. Mind you, not actually sure we told them 8)

Seriously, the service pipe to your house is normally your responsibility, the water company stops at the service valve in the pavement outside your house. Check that applies where you are though.

We were lucky - the water main in our road was replaced about 15-20 years ago, so although the box that holds it was full to the top with soil & stones and we had to dig it out, we had a relatively modern service valve to connect to in the pavement, that previously was connected to our lead water pipe with an adaptor. The valve was seized, but with a big socket on the end of a tommy bar we managed to carefully work it free. If you say yours is new anyway then you should have no problems connecting to it.

Inside the house, the lead water pipe was fairly easy to get at in our downstairs loo and had been soldered to modern copper pipe, the house having been replumbed at some point.

So it was a case of getting the right end fitting from the local plumbers merchant to connect the alkathene (blue plastic water pipe) to Severn Trent's service valve, and at the other end getting an adaptor to connect the alkathene to the 22mm copper pipe just before our stopcock. It didn't cost much. We didn't and still don't have the complication of a water meter. Any plumber should be able to do it for you if you didn't want to do the connections yourself.

MDPE is the other name for the blue stuff, as you can see from the below the pipe and fittings aren't that expensive.

http://www.toolstation.com/shop/Plumbing/MDPE/d20/sd2729

 

[Flyfisher]

Installing a new water main feed here to replace our old lead one was easy & quite cheap, but only because we already had the driveway dug up. That's where the expense is - digging the trenches and making good afterwards, if you get someone else to do it.

Dead right about the cost of digging trenches if it is done by the utility companies.

I've not had to do anything with water pipes but when having new electricity and gas connections both companies suggested I arrange to get the trenches dug myself because if they handled it, it would cost a small fortune because, they explained, they just contract out the work and are not too concerned about the price if the customer is paying. Plus, I guess, they add their own markup as well.

I found that a local 'man-with-a-mini-digger' can dig and fill a lot of trench in a day for about £200.

 

[Feltwell]

I found that a local 'man-with-a-mini-digger' can dig and fill a lot of trench in a day for about £200.

I've a landscaping business run from a house just behind mine, and I found out from a neighbour the other day that the owner's teenage son is quite handy with the mini-digger and his dad is happy for him to use it on Sundays, going rate is £100 cash for the day.

I've a load of tree stumps to dig out and trenches to dig to prepare for planting new hedges - for £100 the thought of making that job a lot easier really appeals. From where he lives he could track the digger round here, no need to even get the trailer out!

 

[MdB]

I'm newly metered for water, so I suppose I will find out when I get my next bill whether the mains pipes are leaking. If the bill is more than seems reasonable for 17 cups of tea per day and a shower every other Sunday then there must be a leak!

Read the meter in the morning (including the position of the dial), go out for the day and then read the meter again when you get back. This will show you both whether or not you have a leak but how big it is too.

You want to find this out now, not when you get your first bill. Leaks can be expensive!

 

[Penners]

I know nothing about this subject, but the only thing that occurs to me regarding a DIY job is regulations. I presume that the correct type of blue alkathene (?) pipe has to be used, and that it must be buried at a specified minimum depth so as not to freeze in winter.

 

[MdB]

I know nothing about this subject, but the only thing that occurs to me regarding a DIY job is regulations. I presume that the correct type of blue alkathene (?) pipe has to be used, and that it must be buried at a specified minimum depth so as not to freeze in winter.

I will be updating our water pipe from the meter in the next year so has a quick look into this. I couldn't find any regs about the type of pipe or depth - well not in Approved Doc G at least. I am sure there are some regs somewhere though. Anybody know where?

 

[Feltwell]

Not sure if there are any regs, but we laid ours at about 2'6" as per this:-

http://www.bristolwater.co.uk/customerservice/newLeadIron.asp

We didn't worry about the bit about keeping the pipe at a certain depth when entering the house - that would have been nigh-on impossible! It comes in alongside the old lead pipe, which never froze, and it survived last winter's extreme cold with no problems. It's also insulated for the first bit outside until it gets to a decent depth.

There was no inspection requirement either, so maybe it varies depending on where you are. I think if the service valve is not right up against your property boundary then the water board may replace that first bit for you free of charge, I know Severn Trent used to.

Oh, and the rules are very different if you have a shared supply apparently.

 

[Flyfisher]

When digging our trenches for gas and electricity we were asked to make them 600mm deep. There was no formal inspection involved, though I suppose the gas and electricity companies wouldn't have laid their pipes if they weren't happy.

When I asked the man-with-the-digger to be careful about the water supply, which we believed to be somewhere in the vicinity, he said it shouldn't be a problem as they are usually about 1m deep. I've no idea if that was actually the case, but we certainly didn't find our water supply.

 

[MdB]

I found our water pipe with a digger - made a nice little fountain for a while

Interestingly, it had a tap connected to it (just visible above), buried maybe 0.5m down...

 

[Lime]

Not sure if there are any regs, but we laid ours at about 2'6" as per this:-

http://www.bristolwater.co.uk/customerservice/newLeadIron.asp

From that link:
"A trace wire must also be laid with your pipe, and clamped to your pipe inside your property."

 

[Feltwell]

It's not a bad idea, but I think that's just for Bristol Water. Each authority seems to have their own requirements, Severn Trent didn't specify that.