Insulating pipe in ground

[marsaday]

The water feed coming through the garden has been frozen for 5 days now.

I am about to dig up the pipe and lag it.

what should i use to do this. The pipe is 22mm (i think) black plastic piping.

I can see it running under our steps and into the cellar wall ( there is a chamber under the steps). the pipe also disappears under some breeze blocks and goes off towards the pavement (5m away).

So i can see it is not deep enough where it disappears under the ground, but it may go deeper.

So rather than bury it any more, i just want to insulate it. Will 22x19mm lagging be any good ?

 

[HERTS P&D]

Having the pipe work buried at the correct level would stop it from freezing. 750mm deep.

The insulation will get wet and hold water which will then aid the pipe to freeze even more.

Andy

 

[marsaday]

But i cannot cut the pipe and bury it deeper. It is a continuous piece of pipe from the pavement all the way into the cellar and then through the cellar to the other side. this is where the stop tap is and it goes onto copper.

Insulating is my only option really and it has never frozen before in the last 10 yrs.

 

[xr4x4]

thats because the temps havent gone down to lows of -10oC.

 

[ianniann]

As Andy half worked out, you wouldn't use rags or newspaper to insulate in this situation. You need something that will maintain its porous insulation value even in contact with wet ground. My first though was a vermiculite concrete which is a fairly good insulator, but even a very weak mix would be a nuisance to dig up again and I don't know if it would resist water well enough. Perhaps someone can suggest a better material, otherwise you might have to enclose your insulation in a waterproof layer.

You could certainly bury the pipe deeper but it would be a big job. Of course it may not freeze again for another 10 years. You might find it simpler just to run a dripping tap continuously if we ever have a cold snap like this again. It is stationary water that slowly cools down in contact with frozen ground and eventually freezes. A constant supply of less cold water from the mains will not freeze.

 

[fingertight]

I f you want a cheap option why not try polystyreine (or however its spelt..looks spelt fine to me..I am on my 3rd guiney pop though) build in a block shape round pipe...ground freezes from the ground down so if pipe is "poly squared off" it may buy you that few degrees difference.

Or better option is armaflex insulation..google it...dogs bo**ocks. costs more than mormal stuff though...it is rubberised and not porous..tested down to minus 15 and has to be glued onto the pipe

Good luck!

 

[JohnD]

does Climaflex get wet then?