redtop Posted June 26, 2019 Share Posted June 26, 2019 we have two options:- one requires a small section of road to be dug up and then we are onto our plot. And then a long (circa 75M) run through our plot which rises about 7M. The other requires connecting to the mains on the road, and then 20 - 25M under a paved footpath which has every service imaginable under it including a gas main (but no water). This would then involve about 10M or so on our plot and is downhill all the way by about 5M. We have received a quote for the first optopn at £1,700 (to take it to a meter just inside our land which would have a temp supply fitted to it). We would then dig and run the long underground pipe later once the structure is up. This is for a 32mm feed. I am waiting for the quote for the 2nd option but assume it will be a lot more given the amount of work needed to run it under the path. But its closer and downhill... Any views on whether the first option would work or would the long uphill drag reduce water pressure to a trickle?? Link to comment Share on other sites More sharing options...
Patrick Posted June 26, 2019 Share Posted June 26, 2019 8 minutes ago, redtop said: I am waiting for the quote for the 2nd option but assume it will be a lot more given the amount of work needed to run it under the path. But its closer and downhill... Wait for the second quote. In my small experience the Utility quotes do not necessarily follow logic. I had quotes for silly small work that where ridiculous and larger jobs that where surprisingly cheap. Link to comment Share on other sites More sharing options...
redtop Posted June 26, 2019 Author Share Posted June 26, 2019 the 2nd quote is non utilities, but from an approved installer. The utilities didnt want to quote for that option as the path, although public, is apparantly privatly owned so i would have had to dig that... The approved installer was happy to quote because the house alongside the path were happy for the work to be done, and nobody knows who actually owns the path. Didnt seem to be an issue for Gas, electric or BT but water company didnt seem interested. Link to comment Share on other sites More sharing options...
ProDave Posted June 26, 2019 Share Posted June 26, 2019 Forget the uphill / downhill bit. This is mains water under pressure, the end point is the same regardless of how it gets there. Link to comment Share on other sites More sharing options...
redtop Posted June 26, 2019 Author Share Posted June 26, 2019 ok, not sure i understand that but then fluid dynamics confuses the hell out of me! i know its coming off a 100mm mains, but dont suppose that makes a difference. Link to comment Share on other sites More sharing options...
Conor Posted June 26, 2019 Share Posted June 26, 2019 (edited) A lot depends on the pressure in the mains you are tapping in to. are both options coming off the same main / supply area? A 7m rise is nothing - 0.6bar drop in static pressure. You will need a 32mm supply pipe for that length tho. Water in a pipe is easy to understand. Pressure drives flow, higher flow and therefore higher velocity results in pressure loss. The longer the pipe, the more friction there will be and the greater the pressure loss as flow rates increase. The way to get around that is a larger diameter pipe. 32mm over 25mm may not sound like much, but you'll have significantly less pressure loss. Try and find out from the water company what pressure the mains are at. And the diameter of the host main is largely irrelevant. Utilities aren't really an issue when installing a supply pipe, there's plenty of scope to avoid as your supply pipe is small and flexible. I'd go with the cheaper option. Edited June 26, 2019 by Conor Link to comment Share on other sites More sharing options...
redtop Posted June 26, 2019 Author Share Posted June 26, 2019 Sorry, just been busy checking the elevations, its 10M up or 10M down depending which option i take. Yes 32mm supply pipe is planned and has been quoted by south west water for their 'uphill' option ? Link to comment Share on other sites More sharing options...
Conor Posted June 26, 2019 Share Posted June 26, 2019 41 minutes ago, redtop said: Sorry, just been busy checking the elevations, its 10M up or 10M down depending which option i take. Yes 32mm supply pipe is planned and has been quoted by south west water for their 'uphill' option ? If the pipes you are taking off are on the same part of the network, it's irrelevant if they are 10m higher, or lower than your property - the "head" in the pipes will be the same. Seems the two factors you are dealing with are distance and cost. Link to comment Share on other sites More sharing options...
redtop Posted June 26, 2019 Author Share Posted June 26, 2019 OK, so basically, assuming both mains are the same pressure the only difference between going 25M long and 10M down V 80M long and 10M up is the loss associated with the length of the run. Height dif makes no difference. Given we are using 32mm pipe i would have thought the long run would be OK then. Certainly it will be a lot chepaer (trench on our land dirt cheap, trench in public footpath isnt) for the longer run Link to comment Share on other sites More sharing options...
Conor Posted June 26, 2019 Share Posted June 26, 2019 Yep, 100% Link to comment Share on other sites More sharing options...
Temp Posted June 26, 2019 Share Posted June 26, 2019 Which route will other services take? Can you share a trench to reduce costs? Link to comment Share on other sites More sharing options...
Conor Posted June 26, 2019 Share Posted June 26, 2019 Good luck coordinating other services. They will all have their own requirement, e.g. trench depth and clearance from other services. Normally if you have congested services in a footpath, they will be at various depths. With water usually lower, along with electric. Telecoms tends to be shallower. NTL / Virgin just under the bitmac lol. Once on your land, less of an issue. Link to comment Share on other sites More sharing options...
redtop Posted June 26, 2019 Author Share Posted June 26, 2019 not even trying. Elec is already on site and temp connection done. Gas comes from other end as does sewage but from a slightly different direction. Western power have been great, SW water less so. Gas will be easy, sewage will be via private contractor and havnt approached BT yet Link to comment Share on other sites More sharing options...
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