Quote for new water mains supply - is it reasonable?

2point4

Hi all

We have a water leak somewhere under our house. It's not visible and we have concrete floors. Water board have concluded after a few visits that there is no leak in front of the house from the water meter so must be under the property.

The water main sits under an extension so would need to dig up the floors to find it but a company have suggested that they run a new supply round the other side of the house using a mole. Access wise, they would go in half way down the drive where there is a recent patch and then round the house under a hard standing at the front and then soft path down the side and then patio slabs rounds the back.

It would be approx 35m of 25mm mdpe and they say it would most likely be a 2 day job. We have received a quote of £3,750 including VAT. This is not covered under our insurance so we are paying it ourselves.

We are working on getting some other quotes but wondered if this was in the right ball park? The quote is given as a fixed fee unless they hit unknown groundworks or services i think.

Thank you

Grumpy_chap

https://forums.moneysavingexpert.com/discussion/6653438/quote-for-new-water-mains-supply-is-it-reasonable

Sounds like quite a good price TBH.

£3,750 inc VAT is only £3,125 for the company. Two days for two people (minimum) so for working days plus the tunnelling machine plus materials to do the job plus reinstatement.

Get another quote to price-check, but that number does not seem shocking.

ComicGeek

You could probably do it cheaper by digging trenches, but the reinstatement costs would be considerably higher without the mole. So probably similar cost overall with more disruption, more time etc.

Why 25mm MDPE though? Is that to match the existing pipework size? For that distance I would normally use 32mm

Swipe

I had a mains supply installed via a mole around 15 years ago. I think they charged £30 per meter plus £150 extra to access the kitchen. It was 25 meters and came to about £1200 if my memory serves me correctly. It took them less than a day and accessing the kitchen took as long as laying the pipe. I think they underestimated the work involved due to very sturdy foundations.

Ms_Chocaholic

We also had to have a new mains supply moled under our block paved driveway, down the side of the house and in at the back. Again it only took one day to do but it only cost around £1,500 ish. This was around 10 years ago. We used Watermains and Drains in the North West of England and they did an excellent job. Make sure you get a WIAPS approved contractor.

https://www.watermainsanddrains.co.uk/

rob7475

We had a new water main run in around 3 year ago to replace an old lead shared supply. The guy who ran the pipe from the pavement at the front of the house to the stoptap in the cellar at the back charged £900. The run was around 15 metre under a tarmac driveway so he moled it with a couple of holes dug along the way.

Price included capping off the old lead supply outside, new stop tap etc and making good the tarmac.

I struggled to find contractors to do the work for a reasonable price - other companies were wanting closer to £2k

2point4

Thank you all for the responses.

A bit mixed there then from experiences? I am still waiting to get a couple more quotes but will come back with them for completeness. It seems that £3,750 could be top end although i appreciate it's difficult to say exactly without seeing the area.

@ComicGeek , why do you suggest 32mm instead of 25mm? Would this be because of the pressure over that length? I can check if that's a match to existing sizing.

Grumpy_chap

Swipe paid £1,200 fifteen years ago. Allowing for inflation, that would be £1,800 now.

Chocaholic paid £1,500 ten years ago. That would be £2,100 now.

WIAWSNB

https://forums.moneysavingexpert.com/discussion/comment/81867958#Comment_81867958

35m is a fair run, but 25mm will almost certainly be ok for domestic purposes, and is standard. I've seen some suggestions that 32mm might make sense in certain situations, say the run is very long, or the street supply pressure is weak.

Yes, the larger size would be to reduce friction over that length.

I suspect you'll be told that 25 is correct, and possibly they won't even entertain a deviation from this, I don't know. But the added cost of 32 should be minimal, and even if it makes no difference, at least you'll 'know' it's optimum!

Reducing it at each end to suit the fittings should not be an issue.

Have a chat about this with each installer?

(But almost certainly 25 is absolutely fine.)

ComicGeek

32mm is what we install for new houses - 25mm is what we install for small flats. Given the very limited cost difference, I would want 32mm unless there is an issue with connecting to the existing. Flow rate through 32mm is nearly double that of 25mm (1 l/s compared to 0.6 l/s), and it can make a difference with pressure over that length.

What you definitely don't want are any buried fittings that could/will cause future leaks, so I would only use 25mm instead of 32mm in that case.

Section62

https://forums.moneysavingexpert.com/discussion/comment/81869627#Comment_81869627

Normally I'd be all-in for future-proofing especially if the cost difference is marginal. In this case I might pause for thought though. Given ever-increasing water bills (and they have a lot further to go up) I'd be mindful that historic (and in some situations current) billing has been based on the diameter of the service/supply pipe. Larger diameters being charged at a higher rate.

Although it may not be the case now, I think it is plausible that (standing) charges in future might be weighted according to supply pipe diameter. Therefore the choice of 32mm vs 25mm might have an annual bill cost in the future. I'm not suggesting this will happen, only that it is something to consider in the mix.

If 25mm is more than enough (given current flow/pressure levels) then I'm not sure I'd go up to 32mm just for future-proofing. Because there is a risk (no matter how small) that the future might involve a higher standing charge. Personally, if 25mm was problematic then I'd probably lean towards going old-school with a cold water tank in the loft, although that would depend on what other costs might be involved in doing so.

Obviously there is another option of running the bulk of the pipe in 32mm and only having a short length at the meter as 25mm. But as you point out, having the necessary reducing coupler increases leakage risk, so may not be optimal.