Renewing mains pipe with blue pipe

[ey143]

When replacing the old lead or copper cold water supply from the street to inside the property, if the main stopcock and meter is in the street pavement, are we allow to connect the new blue pipe to the street stopcock or can we only go up to the boundary?

In our case we have a double thick high wall between my front garden and the boundary line so I don't know how we can fit the new pipe to the stopcock which will have a 28mm or whatever size connection.

We also had a plumber suggest that we should go 32mm or 36mm blue pipe into our property because we have 5 bathrooms and 2 W/C (of course not all will be used at the same time). We have internal 22mm pipe runs branching off to 15mm in each bathroom. Will eventually have a 300litre mega flow so he's saying for the increase in marginal cost of material, we might get better flow rate even if the mains pipe it connects to is going to be small than our bue pipe.

Any thoughts?

 

[xm77]

As I understand it....
Only plumbers approved/registered by the local water company can dig in the public street to connect to the stop valve/water meter in the street
you cannot (legally!) do it.

Depending on the age of the original pipe to your house in the street it might be lead, or quite often 3/4 inch galvanised steel pipe. If the stop valve is new/or a water meter fitted they would have fitted a boundary box unit containing the meter and stop tap into which push fit 25mm MDPE pipes go on either side and they would have used a universal fitting to connect the short lengths of 25mm MDPE to whatever were the pipes on either side of the meter box.

I'd go for 32mm I did not think there was a 36 I thought the next size up was 50 which will be a LOT more expensive - all depends on the length of run as to how much friction losses there are in the pipes. I did know a large rural house a long way from the main down the driveway which was having a new pipe put in and they used 50.

The main supply pipe in the road will be 3 inch cast iron most likely.

 

[ey143]

Thx for your reply.

This is my meter contained in a boundary box. The pipe run would be approximately 12 to 15m.

How on earth would anyone even with a moling machine connect to the other side of this without disturbing the pavement.

 

[denso13]

As above, you can only replace the supply pipe up to the boundary. 32mm would future proof things a bit.

 

[ey143]

So the bit I dont get, is I dont know what old size lead pipe is connected in the side meter chamber to them come under my boundary and then all the way into my home. I bought the house a few years ago and whilst we have good pressure, we want to renew the mains.

It would be pointless connecting 32mm blue pipe to 0.5m of my existing 15mm lead pipe (if it is that - I'm guessing and have no idea) inside of my boundary wall just because I cannot touch or connect to the mains stopcock. I will continue to suffer pressure loss of 15mm coming into 32mm.

What am I not getting here?

Also what is the cost difference approx between 28mm and 32mm?

 

[xm77]

Well, yes: if you leave a section of narrow lead pipe in then this will limit the flow so regardless of what large size the rest of the pipework is then quite possibly the short section of lead will be the limiting factor as to what flow rate will come out at the house depending on the length of the lead section.

Indeed I myself have exactly this scenario. I have a few meters of lead after the meter/stop valve followed by lots and lots more meters of 1.25 inch galvanized pipe: the flow rate is not good. Living on my own here I simply cannot be bothered to change the lead - though I do have the advantage that I'm on a private road so the meter outside on the rural verge is technically speaking on my own land - so in my particular case I could do it myself.

 

[ey143]

Is it a good idea to fit my own chamber with lid on top where I plan to start digging on my side of the boundary where I would connect my 32mm pipe to "whatever currently exists" so I have access to it in future in the event of a leak or anything. maybe use a manhole cover, as ugly as it looks?

 

[xm77]

To be honest I wouldn't bother - just make a VERY careful note with measurements exactly where it is.
Given that the regs say that the water pipe should be a absolute minimum of 750mm down in the ground this means than to reach it the next person is going to have to dig round it to physically get into the trench/excavation to enable them to reach and do the connection.
If it was just 12 inches below ground then the next person could simply reach down lying on the ground to do the link up.
My old pipe is 3ft down.

 

[cdbe]

Have you checked with your water supplier? Most offer a free lead pipe replacement scheme where if you lay a new supply pipe to the boundary they will connect to the main and remove the lead on their side (in your case either the bit to the meter or on both sides depending on what's there).

Also worth checking the maximum diameter of service pipe the water company will allow.

 

[ey143]

Have you checked with your water supplier? Most offer a free lead pipe replacement scheme where if you lay a new supply pipe to the boundary they will connect to the main and remove the lead on their side (in your case either the bit to the meter or on both sides depending on what's ther
Also worth checking the maximum diameter of service pipe the water company will allow.

That's a good point. I called them after you msg. Speaking to developer services they said that I'm not allowed to connect my new pipe into the chamber box stopcock and that if I wanted 32mm pipe or more it will cost £150 odd for an application fee and the cost of changing it will be between £1k and £4k. If however, I wanted to avail the lead pipe replacement service I had to call another number in Operations. When I spoke to them they said the developer services dept was incorrect and that I CAN connect my new pipe into the chamber box stop tap. I have asked them to put that in writing to me which they have done. He clarified that I can have 32mm pipe on my side of the boundary but that they will only put 25mm for the communication pipe (service pipe?) unless I pay to upgrade.

Water pressure from 25mm to 38mm with the slight bottleneck will I presume, still be better than 25mm throughout? Also, looking at that picture, how easy will it be to put an adapter on that to go from 25mm to 32mm?

 

[cdbe]

I don't understand fluid dynamics but I believe yes. 25-32 is simple with a philmac adapter or similar.