Splitting the main supply in to 2

[Monsoon]

Ive got planning and building regs approval to convert a property in to 2 self contained flats.

At present I have a metered supply which is connected to a 32mm MDPE pipe.

I have spoken to the water supplier re: the conversion ... and they showed little interest in getting involved

Can I just T off the 32mm pipe and ask them to fit a meter for the new flat?

Will a 32mm supply be sufficient to service 2 combi boilers without having to have a new pipe laid from the mains in the street? (Mains pressure tested at 3bar)

 

[BoxBasher]

You probably asked the wrong person about it, the average joe in the call centre won't have a clue.

Ask to speak to their byelaws/water regs department or see if they have a property split/merge department.

The static pressure isn't the problem, its the flow. As far as I'm aware you can't fit a combi on a common supply pipe (which is what you will be creating) although one of the boiler boffs will be able to tell you that better than I.

Where is the water meter, in the property or outside in the footpath? If its in the footpath you can't touch any of the pipework because:
a) it belongs to the Water Co and it isn't yours to touch/meddle with and;
b) you need to be streetworks approved and have water/sewer/gas/electric mains records as well as an opening notice from the local highways department before digging in a footpath.

 

[Agile]

A 32 mm supply should give adequate flow to run two combi boilers but should be tested first to ensure there is say 40 litres per minute total from an open pipe.

If the meter is in the street then you can either have a private sub meter and devide the cost if you are to be letting. If selling then you do need seperate meters and the usual way would be to fit them to the 32 mm just outside the property as they dont like internal meters any more.

Most water co.s will want to fit the meters themself at your cost but some will supply the meters and let you fit them.

A street meter has a plug available to remove the meter and have another further on.

Tony

 

[BoxBasher]

they dont like internal meters any more.
Tony

Water co's are still fitting internal meters round here, although they do prefer them outside.
They are tending to favour Intex or Groundbreaker boxes as an alternative to street furniture on new developments, but I'm not sure if either of these would be suitable for a conversion (groundbreaker might)

If the meter is in the street then you can either have a private sub meter and devide the cost if you are to be letting

Can get messy though, and creates problems if selling in future...

 

[Monsoon]

The meter is located in the meter cupboard outside my property. The plan is to put the new meter along side the original.

I will contact the supplier again to find out how they want to play it.

Out of interest If we know the diameter of the pipe and the bar pressure isn't it possible to calculate the flow rate without physically measuring it in a container?

 

[BoxBasher]

No, not unless you can accurately calculate the friction loss through the pipe, fittings, meter etc. Pressure is not constant either... it will vary according to distribution demand.

 

[Agile]

It is theoretically possible to calculate the flow resistance through the 32 mm poly but you have no information of the impedance of the supply network its connected to.

Perhaps its really connected directly into a 100 mm pipe but even that would have an elbow at the connection.

It should be good but if you dont measure you dont know!

Tony

 

[Monsoon]

Just an update.

I've spoken to development services at the water co. - They say:

It's not possible to split the existing supply.

Every property has to have its own pipe from the mains on the street.

Explained that this would mean running a new pipe over 30 meters along a privated shared drive.

They said thats the regs .....

 

[Monsoon]

Anyone have any experience of this situation?

Can they really insist I have a new run of pipe when I could just T off the existing pipe(subject to flow rate tests)?

Can they stop me sub-metering the supply to the other flat?

Does anyone know the regs they are referring to? maybe they are published online and I can see it in B&W.

My own house has a single pipe which serves myself and my neighbour so certainly in the past it must have been done.

 

[Agile]

It has been common to have a shared supply pipe.

I have a house fed across the back garden from the adjoining house! Most of the houses have their own supply and just mine does not.

I dont see how they can stop you sub metering.

There may not be any regulations as a law and you may just be up against the policies of the Water Co.

Which one is it?

Tony

 

[BoxBasher]

Recommendation 10.4 "WRAS Water regs guide"

" The Water Acts normally require premises to have seperate supply pipe wherever this is possible..."

This would indicate that the requirement is within the Water Industry Act, rather than Water Regs.

"wherever this is possible" - it is possible in your case, you just don't want to.

usual exceptions/exemptions from this requirement would be in the situation of "multi-occupancy dwellings" where running in 5/6/7/8 services would be too complex and therefore a 63mm or larger single supply is run into the building and the seperate supplies are all fed off a manifold.

I'm not sure that you would get an adequate supply for two dwellings down 30+ meters of 32mm PE.

 

[Agile]

I have a house fed across the back garden from the adjoining house! Most of the houses have their own supply and just mine does not.

The Water Co ( ST ) replaced the main in the street passing my house but even though I had previously contacted them about the inadequacy of the supply ( 0.6 li/min open pipe ) they did not take the opportunity to give me my own supply pipe.

Do you think that I have any complaint against them in the circumstances?

Tony

 

[BoxBasher]

Tony,

It would be your responsibility to bring a pipe from your property to the highway boundary. They may charge you for a connection... (I assume you are in Thames area).

I know my local water co does a free connection for people replacing lead or bringing out a single supply to abandon a shared pipe.

 

[Agile]

Tony, I know my local water co does a free connection for people replacing lead or bringing out a single supply to abandon a shared pipe.

No, this is ST. Do you know what their policy is?

Unfortunately, the contractors had passed the house before I found they had not put my new connection. I had assumed that as all the other houses were being renewed they were also going to do mine.

Tony

 

[BoxBasher]

Tony,

Sorry for the delay, been on call.

Is your supply lead? I'm assuming it is as most shared supplies are (that I've come accross) with a few exceptions such as Galv or AC.

With regards to lead replacement ST will carry out a free connection provided you bring your pipe out to where they specify (usually nearest main in street.) I'm pretty sure you'll have to fill forms out first and to add insult to injury they'll want to inspect it to make sure you know what you're doing...

Policy available as a PDF