New Water Main

[wozza]

Hi All,

 

Quick question about new water main to our extension.

We currently have ok pressure / flow - it enters the house under the sink via a black pipe around 25mm - it is then reduced via a stop cock that feeds the house.

As we are moving the kitchen, we are having a new water main fitted by the builder - this can be whatever size we want.

My plan is to replace the 15mm pipe from the stopcock that feeds the house and the boiler with 22mm to give as much flow / pressure as possible as we are having 2 extra bathrooms.

 

Would we benefit from a 32mm pipe from the mains to the stopcock (it may connect to the 25mm black pipe near to the street or should we stick with 25mm?

 

Thanks.

 

Wozza.

 

 

 

[Nickfromwales]

25mm is a decent sized main for a domestic dwelling. You may be having extra bathrooms, but you'll likely not use them all simultaneously. 

If you think you will use them / have very high DHW demand then I doubt fitting a 32mm main to the existing mains ( street ) supply will make any notable difference TBH.

 

[epsilonGreedy]

1 hour ago, wozza said:

Would we benefit from a 32mm pipe from the mains to the stopcock (it may connect to the 25mm black pipe near to the street or should we stick with 25mm?

 

 

How long is the external pipe run from the mains to your property wall?

 

There is an industry recognized threshold at which point 32mm is recommend, I think the number is 40m.

[wozza]

2 hours ago, epsilonGreedy said:

 

How long is the external pipe run from the mains to your property wall?

 

There is an industry recognized threshold at which point 32mm is recommend, I think the number is 40m.

 

From the connection to the stop cock will probably be about 30 meters

 

Ok, think we will go for 25mm to the stop cock.

 

How much difference would using 22mm from stopcock to the boiler and main run make, then teeing off via 15mm to taps, toilets etc.

 

Nick FW - Yeah doubtful that we will use all the bathrooms at once but just want to try and reduce the effect that running a tap in another room has on the shower. So thinking a bigger pipe would be better?

[Nickfromwales]

2 hours ago, wozza said:

 

From the connection to the stop cock will probably be about 30 meters

 

Ok, think we will go for 25mm to the stop cock.

 

How much difference would using 22mm from stopcock to the boiler and main run make, then teeing off via 15mm to taps, toilets etc.

 

Nick FW - Yeah doubtful that we will use all the bathrooms at once but just want to try and reduce the effect that running a tap in another room has on the shower. So thinking a bigger pipe would be better?

I'd deffo go for a 22mm 'backbone' and drop to 15mm when you et to the last 2-3 outlets. What hot water device are you fitting? UVC? 

[epsilonGreedy]

11 hours ago, epsilonGreedy said:

There is an industry recognized threshold at which point 32mm is recommend, I think the number is 40m.

 

 

Anglian Water recommend using 32mm above 40m.

 

See page 8.

https://www.anglianwater.co.uk/_assets/media/LED645_AW_DS_Connecting_10_steps_20pp.pdf 

[wozza]

On ‎07‎/‎01‎/‎2019 at 23:31, Nickfromwales said:

I'd deffo go for a 22mm 'backbone' and drop to 15mm when you et to the last 2-3 outlets. What hot water device are you fitting? UVC? 

 

Hi Nick,

 

Its just a normal Combi Boiler at the moment that is fed from the stopcock via a 15mm pipe, but for the sake of a few quid I want to upgrade ready if we do change and also to help reduce any future flow issues.

[Temp]

We have a 25mm supply to the house which works but we see some interaction between outlets and I would fit 32mm if building again. This interaction is not due to pipes within the house. If you fit 32mm pipe you can still fit a 25mm meter so no extra charges. 

 

We are in an area prone to burst water mains. Its burst three or four times in 10 years. Each time I get the impression Anglian Water turn the pressure down a bit to try and prevent it happening again.