Replacing lead water main

[BruceyP]

Hi Guys,

I'm currently in the process of replacing an old lead water main. From what I understand 32mm is probably the best option to improve water pressure/even flows between running taps. The current water main runs for about 3m from the main stop tap under my front path and into my basement to a stopcock at about chest level. It then runs through copper pipe (15mm i think) to the otherside of the house into the kitchen (about 18m away). I have 2 questions.

Firstly when lagging my pipes, I presume as I have a basement, I need only lag the pipes between entering the wall and leaving the wall as it comes into the basement? The basement currently has no central heating (this is to change) but I don't imagine it ever getting cold enough to freeze. Just wandering what the regs say as all i can find about is lagging up to floor level in houses without basements.

Secondly to get full benefit of the 32mm pipe should I run as much as I can. i.e. run it all the way through to the kitchen and remove the copper as I go (obviously protecting it from rats etc). Will this make little difference? Or even too much flow (if this is even an issue)?

Thanks, any help or advice would be much appreciated

 

[landyandy]

Have you been accepted onto the lead pipe replacement scheme. If so you should have received details of how to run your new supply pipe.

Your new supply will have to be inspected unless you use a wiaps plumber who can self certify.

25mm is the norm.

your pipe will need to be sleeved and insulated before it enters your property, then insulated under floor.

Andy.

http://www.unitedutilities.com/Documents/1344_How_20to_20lay_20new_20pipe.pdf

 

[BruceyP]

Thanks thats great. Well that certainly answers question number 1. Can anyone help or advise on the second question?

Thanks.

 

[muggles]

If you're running 32mm then you should run it all the way to your stopcock or there's little point. Ideally from there it should be 28mm copper but it rather depends on what your water requirements are. How big is your house, how many occupants and how many bathrooms? What kind of boiler/cylinder setup do you have?

 

[fingertight]

I heard that if you are having lead replaced with 25mm MDPE or under, its free??

I havent double checked so keep your pepper spray in your pocket if im wrong.

 

[BruceyP]

Well the the thing is the stopcock is located in the basement only about 3m from the mains stop tap. This is why im questioning whether it would make much difference.

I guess I would run it all the way back to the kitchen and fit a new stop tap in the kitchen.

My House is fairly large, 4 bed and a basement. My boiler is a combi boiler, don't know anything more than that. Im looking to upgrade the boiler at some stage as it will be too small for the yet to be completed basement conversion and loft.

As for the rest of the copper piping, im guessing it wont hurt to have 32mm pipe running into 15mm? Or will that cause damage?

From a cost point of view id rather put in the biggest bore piping as it relatively cheap and seems to make sense to future proof the house if I want to later upgrade everything else.

What I don't want to do is damage the boiler and existing copper piping by having to bigger flow entering the house. (if this even an issue)?

 

[JohnD]

there is no such thing as too much flow.

don't reduce to 15mm before the tees. i.e. have the big pipe feeding the kitchen tap supply, and also feeding the bathroom supply, and also feeding the boiler supply, and also feeding the loft tank supply (if you have them)

then you will not have several outlets competing for the same 15mm

when I did one last year I ran new 20mm plastic up to the loft tank, it fills quieter, does not vibrate, was easy to run up the duct as flexible.

I am a householder not a pro.

Ask you water supplier to check your tap water for lead content before you start work and you should get a subsidy. If you leave it too late you won't.

I'd lag it all with thick Climaflex as you go. Easier than retrofitting it later as you can slide it over the pipe with no slitting. Protect all stopcocks and connectors extra-well.

 

[BruceyP]

Thats superb thanks very much.