Water flow problem-leak between mains and internal stop-cock

[seanmac30]

Hi,

I have a waterflow problem in my home. Basically, my flow is < 10 L/min and things get interesting when someone flushes the toilet while someone else is in the shower! Anyway I have had enough of it & I want to get it fixed. I have had the water company check the flow from the mains and its is fine (35 L/min). Using my great powers of deduction, I have a leak underneath the drive or under the house (hopefully not). I cannot locate where the water comes into the house (probably in a wall or under a concrete garage floor!) and the stop cock is located in the kitchen at the back of the house (the mains are at the front). I thought one way to diagnose if the leak is between the mains an the stop cock would be to run a temporay pipe overground and connect it just before the stop cock and test the flow then (sorry very simplistic and I have no idea if it is feasible).

My questions are:
Is this a job for a regular plumber or do I need a specialist?
Is it possible to retire the old pipe coming from the mains, dig a trench, lay a new pipe under the drive and run a connecting pipe into the garage and connect it to the stopcock in the kitchen?
How much is this likely to cost?
Will I need to get permission from Yorkshire water for connecting a new pipe to the mains.
Could I claim this on my buildings insurance?

Any suggestions or advice would be very welcome. Thanks,

Johnny

 

[JohnD]

how do you know that you have a leak and not a constriction in the pipe?

 

[dcawkwell]

Firstly the stop valve may not be opening fully.

You want to check with your neighbours and see what sort of
flow they are getting.
If they have good flow then my first suspect would be the stop valve
in the house. Replace that first.

Failing that dig a trench run pipe to the house. Fit a 22mm stop valve
and connect to the nearest cold main pipe in the house. Cap off the pipe
at the old stop valve.

 

[seanmac30]

how do you know that you have a leak and not a constriction in the pipe?

I don't ....it could be a constriction but how do I find out? It looks like I could call Yorkshire Water to investigate if there is a leak but I'm a bit hesitant because they can issue orders to get remedial work done skin 14 days if there is a substantial leak. I could do without that pressure if you can excuse the pun

 

[seanmac30]

Firstly the stop valve may not be opening fully.

You want to check with your neighbours and see what sort of
flow they are getting.
If they have good flow then my first suspect would be the stop valve
in the house. Replace that first.

Failing that dig a trench run pipe to the house. Fit a 22mm stop valve
and connect to the nearest cold main pipe in the house. Cap off the pipe
at the old stop valve.

I will replace the stop valve and see if it makes a difference! I have a tap near the garage door so would I be alright just connecting the new pipe from the mains the pipe that feeds the the garage tap?