Frozen Pipes no water

Tomjim

For the last 2 years my water has frozen in the path outside the house in the severe weather. The water pipe is just under the concrete path ie 4 inches underground. When I put fires on the path I got it going as this thawed out the path/ pipe.

Now I have cut the path and am going to dig the pipe down a bit into the ground.

What depth should the pipe be inder the path, note there is mostly gravel under the path.

Is there anyting I can put on the water pipe to provide it with protection from the frost.

heinbloed

Depending where you life - the frost exposure situation - 30-40 cm should be o.k. Pack the pipe in sand, cold air flowing around it would make it freeze again (coarse gravel!).
If you can't dig that deep there are electric heating elements available. Purpose made cables laid next to the to-be-protected pipe.

Buford T Justice

afaik the recommended depth is 700mm

DoneDL

750 mm is the minimum required depth.

Joey the lips

Its impractical to lay a water pipe covered with electrical cable imo. Just bury the pipe as deep as possible,

slavetothegrind

http://www.heattracingsystems.ie/Pdfs/Frostguard.pdf

product similar to above i think heinbloed is suggesting which is not unreasonable if the cost of sinking the pipe is too much
At 10 watts per metre it doesnt use much power either and is thermostat controlled, fitted in insulation of course.

( not linked with or endorsing above brand or company)

heinbloed

Above Fingers McGee and DoneDL say 700-750mm is the minimum/recommended.
Is there some official data available, building regulations or the like?

As far as I have seen no pipes bursted last December layed in 300mm depth, but I haven't seen them all (smiley).

Checking the Met Eireann data I came across limited information, see

http://www.met.ie/climate/monthlyBulletins/jan10_lores.pdf

There at page 6 we see average temperatures at 300mm depths for the coldest January within the last 25 years (2010). Some strange values included where the data sugests it was colder below at 300mm than further above...
At page 8 of the document record soil temperatures are mentioned of down to -15 degrees Celsius but this is only the top soil (at 100mm depth as far as I know) at the 9th of January 2010 in Claremorris.

Thanks!

DoneDL

UK Water Regulation Advisory Guide. The reason for the depth is as much to protect from frost as it it is to keep the water supply cool to prevent unneccessary wastage in summer.

heinbloed

Thanks, DoneDL.
So no Irish regulation/legislation?
I'm sure the (extreme) climatic conditions differ from the UK to Ireland?
Has someone seen water pipes frozen at 30 cm depth in Ireland?

slavetothegrind

http://www.fingalcoco.ie/Publications/Water/Guidelines%20for%20Drinking%20Water%20Supply.pdf

page 3

Billy Bunting

My mains key is only 600mm long

Joey the lips

Billy Bunting wrote: »

My mains key is only 600mm long

Yip... But your elbow is another 600mm as well. Thats why the shore is wide

heinbloed

Thanks, slavetothegrind !

So 750mm to make work easy for others but not for frost protection I guess, see point 6 at the same page:

6. No other service is to be located above or within 500mm of any watermains,
unless it is crossing over the watermain at right angles, where there must be a
minimum of 250mm vertical clearance.

If frost was expected at this depth (or below 300mm) the city's strip foundations would heave away!

But at least some official statement.

brembo26

seen this on dragons den was it last night or the night before? stop cock cosey now its supposed to work down to -30c but i dunno how it keeps the actual pipes warm???

jprboy

brembo26 wrote: »

seen this on dragons den was it last night or the night before? stop cock cosey now its supposed to work down to -30c but i dunno how it keeps the actual pipes warm???

The same thought occurred to me and I was surprised that none of the Dragons picked up on this, particularly Sean Gallagher.

It doesn't keep the pipes warm, just protects the stop cock. If the pipes between the stop cock and the house are too close to the surface they will still freeze.

Short of digging up paths, driveways, gardens etc, is there any way of determining how deep water supply pipes are?

Micky Dolenz

brembo26 wrote: »

seen this on dragons den was it last night or the night before? stop cock cosey now its supposed to work down to -30c but i dunno how it keeps the actual pipes warm???

I watched this too with great interest. I have first hand experience of digging out several metres of frozen pipe work. It may keep your stopcock ice free. What about the rest of the frozen pipework.

slavetothegrind

in fairness to the cosy, the old type of stopcock is made of brass with as we know hydrodare in and out so the brass tended to freeze up first.
the cozy helped prevent this untill such time as the hydrodare was also frozen.

stuffing the hole with glass fibre insulation also works:)
at least for a while until it really freezes!

the newer type plastic lever valves have an insulation piece included but no harm supplimenting it i suppose...

Joey the lips

slavetothegrind wrote: »

stuffing the hole with glass fibre insulation also works:)
at least for a while until it really freezes!

...

Very bad move. The insulation becomes wet and freezes for longer...