frog

I am in the process of replacing the water mains feed to the house (between stop-cock and raising main).

I've got some 25mm MDPE (sp?) pipe and was wondering what I should use to insulate and protect it.

It will be 80 cm under-ground as required by the local water authority, but I was wondering if I needed to protect it with something under-ground, and, insulate it further with some sort of lagging / foam pipe insulation, etc...

Can't seem to find anything that will fit 25mm pipe

Thanks in advance
Greg

bud-weis

it should be fine left unprotected at that depth....be careful what you use to backfill though, sharp stones will knacker the pipe, and you don't really want much ground movement near the joints.

Have you asked the water company to pay towards the cost of the relay by the way? there's a chance they might

frog

Most of what I've dug up at the bottom is like sharp sand, so I was going to re-use that, taking all the stones out.

What do you mean by "cost of the relay" ? They have already replaced the stop cock with a modern one free of charge when we asked them to check our water pressure/flow, so I'll be linking the new pipe straight into that.

bud-weis

your water company 'may' put up some of the cost towards your new pipe, basically all water companies are trying desperately to reduce leakage, one area where there is still lots is on 'private' pipework (the length of pipe on the customer side of the stop cock).

Fixing these leaks is a ballache because of all of the hassles involved in actually finding the leak to start with, and then making a tidy job of it on someones driveway or garden causing grief. So basically if you told them you have a leak and are willing to replace your own pipework, they may foot some of the bill.

Also if the pipe you are replacing is lead, then they will more than likely help out.....although i can't be sure because it probably depends on the water company.

frog

Yup, I can wee further than the hose pipe in the garden !!!
They told us everything was fine on the supply side (which isn't shared btw, we have our own stop cock), but while pressure was good in the house, there was very little flow...

The old pipe (house built in 1948 irrc) is corrugated iron, I have dug it out and it's got more rust than my 2 fords put together . I haven't cut it open yet, but I suspect it's about half its original diameter inside too !!!

I have been contemplating doing this for years, and got round to it two weeks ago, now just about to put the new pipe in

If you've got a shared supply, you'll probably need to talk to neighbours/water board since any work you do will affect them

Pics below to give you an idea of the work I've done (all by hand btw ).
Haven't got pics of the kitchen where the supply arrives yet either... kitchen units out, floorboards up, you name it...

frog

It never leaked, just didn't flow, looks like pipe is corrugated iron, not lead.
Oh well, I've done most of the work without needing to buy/hire anything so it hasn't cost me much so far except time, sweat and fat (that I've lost )

frog

Just thinking - would I be breaking any building regulations or code by sticking the pipe inside a 2" drain pipe to give it some protection ?

I don't really want to go digging again just because a sharp stone decided to make its way through the pipe

bud-weis

Not necessarily no, but it may be worth buying some shingle that's abit less sharp to avoid it, the trouble with doing that is if there is ever a leak the water won't necessarily come up at the point of the leak, it'll run down the conduit to the easiest exit route, so will take ages to find it. (most leaks don't show at the surface anyway.)

the pipe is fairly tough to be honest..

Another tip : tape a strip of metal to the length of the pipe...that way if you ever sell the house and there's a leak, the pipe will be easier to trace for the new owners/water board.

can't see the pics at work i'm afraid i'll look later on at home

frog

Thanks for the metal strip tip, but I think the new line of concrete along the drive will give the game away (you'll understand when you see the pics ).

I was thinking about leaks and the pipe, as you said, it may not be the best idea.
How about wrapping it in the grey insulation foam you find on most hot or air-con pipes ? I guess that could introduce similar problems with leak diagnosis

frog

I did for years, and got fed up with it... looking forward to a nice warm powerful shower

bud-weis

i can see them now, nice work

The material you've excavated doesn't look too bad, but i'd still put a layer of sand or summat down first immediately on top of the pipe, maybe with some shingle from B&Q or summat, just to help protect the pipe when you start to compress the backfill onto it.

in all honesty your idea about some insulation foam is good, the MDPE pipe very rarely bursts at the sort of pressures you see at domestic properties, the boundary box you now have fitted in place of the stop cock should be good for around 100 m/h (10bar ish) and the pipe will take more...but i bet you only have a max of about 4bar anyway.

the weak points are always the joints, so if you have one long piece end to end then your only weak point is where it joins the boundary box and where it enters your property and connects to existing pipework....so i reckon some insulating foam and the material you have to chuck back on will be more than enough

frog

Thanks Marting

I'll get a few bags of shingles, and some insulating pipe then, take a big breath, remove the old pipe and put the new one in

Wish me luck

Eagle

iTrader: (2)

sand... lots of it .... above and below