Replacing Lead cold water main

[diamondgas]

Hi all,
I'm after advice on installing a replacement cold water main. What are the regs? I have a friend who's supply has dropped to ziltch (0.25bar working - 4bar standing & 7ltr/min max)

what I know nothing about is how deep the trench, does it have to be dug to his original 'Toby', iso outside. and can the pipe be ran under floorboards before the consumer iso valve? Any advice would be appreciated.

Thanks, Steve

 

[Billy Bob Bob]

iso valve should be as near as practical to the entry of the building if going into the outside pavement etc from memory you need to go down 4 ft but not done one for a while and it needs to be in a insulated duct again may be wrong done the last one 4 years ago

 

[diamondgas]

iso valve should be as near as practical to the entry of the building if going into the outside pavement etc from memory you need to go down 4 ft but not done one for a while and it needs to be in a insulated duct again may be wrong done the last one 4 years ago

I've seen plenty but never don one 'gas man' ... Problem is that his original lead comes out at the 'back' kitchen, far side of his house in comparison to his front street main! The lead snakes under floorboards and pops up. I haven't a clue as to what current water regs ask for!

Cheers anyhoo's 🙂

 

[tamz]

Min depth 760 max depth 1350.
Run the poly in the front and under the boards if it make it easier.

 

[kirkgas]

water main needs to be at least 750mm deep, usually bedded in sand to protect pipe then back filled, you ask about it going back to toby, it would need to go back there to be connected (or am i missing something) loads of new builds enter the prop at the front and go under the floor and rise at the other side, it isnt the "perfect" way to do it as there is pipework under the floor that isnt controlled from the iso valve, but what are the chances of a new pipe bursting, and even if it does as long as the customer knows where the toby is and has a key it isnt too big a deal,

 

[kirkgas]

Min depth 760 max depth 1350.
Run the poly in the front and under the boards if it make it easier.

beat me to it again!!!!!!!!!!!!

 

[tamz]

Your is in more detail tho Kirk🙂

 

[WHPES]

Needs to go in a sand filled duct bend where it comes up into the house. Generally a 20mm x 15mm reducing stopcock is used where it comes into the house. Do not put the stopcock too close to the floor (allow at least 4" pipe showing) for future maintenance purposes.

 

[diamondgas]

Thanks guys for the replies. A couple more questions if you don't mind :-0

Do I have to inform the local water authority for inspection or connection?

Does the main have to enter the property 750mm down or can I bring it up to underfloor hight? There's not a great deal of space under the floorboards. I haven't measured it but from memory there's about a foot below the joists B4 ground level. Not sure if that's concrete or not at ground level!

Finally does the poly need lagging where exposed under the floorboards?

Cheers 🙂

 

[tamz]

Thanks guys for the replies. A couple more questions if you don't mind :-0

Do I have to inform the local water authority for inspection or connection? You are supposed to

Does the main have to enter the property 750mm down or can I bring it up to underfloor hight? There's not a great deal of space under the floorboards. I haven't measured it but from memory there's about a foot below the joists B4 ground level. Not sure if that's concrete or not at ground level! You should dig down into the solum so the pipe enters at 760. It should rise inside a sleeve (a 4" pipe with a slow bend through the wall would do) and lagged with waterproof insulation (armaflex).

Finally does the poly need lagging where exposed under the floorboards? Yes

Cheers 🙂

......

 

[diamondgas]

Cheers tamz ..... And the rest of you! I'll put this to my pal and see if he's up for shoveling this Easter !

 

[pobsdad]

Don't do what I saw a couple of weeks ago,and use one of those DIY washing machine self tapping valves BELOW the stop tap!Laugh,I nearly wet myself!

 

[WHPES]

If you replace the section between the company stopcock and the house I think they are obliged to replace their section up to the stopcock.

 

[Joncpi]

Use 25mm PE pipe. It will give a better flow rate. It is possible to get stopcocks for both 20mm and 25mm PE pipe the 20mm ones go down to 15mm but the 25mm ones can reduce to 15mm or to 22mm. There is no need to surround the pipe with sand unless the ground is very stoney. If clay then that is OK. Entering the house can be done with a large diameter pipe but you do need to make a very very big hole in order to get it in. And it does need insulation arond the water main and sealing. However most specialist installers simply drill a 40mm diameter hole down from inside to the excavation outside and install a 38mm sleeve. Insulate the pipe under the floor as it prevents condensation onto the pipe and also any chance of warming the incoming water. There are specialist installers that can install your main without digging up your front garden/drive. They use "moles" these are thrust boring machines or soil displacement hammers. Some water authorities will connect free of charge, in fact most will if you are replacing a lead service. Also some will give you a rebate on your next bill if you replace your pipe! I know Portsmouth Water does. You can not take the pipe all the way to the meter or external stopcock as the bit of pipe in the footpath to your boundary is the responsibility of the water authority. also you need a Street Works ticket and an Opening Notice from you local council to "Open the Highway" You need to leave the trench open for the Water Authrity to inspect. I would suggest you contact them first. I have always found the inspectors very helpful, thats is once you can get through to them!

 

[Joncpi]

Only if it is lead are the Water Authority obliged to replace the section from the main to their stopcock in the footpath

 

[diamondgas]

Big thanks Joncpi,
You've explained it perfectly cheers! Most helpful!!! I was wondering about the front street! Now I know 🙂