How long is too long a piece of pipe?

[HyFy]

I've been checking in a void below our house to see how good the insulation on the pipework is prior to leaving the house for an extended period in January and February, when I saw a very long straight run of 15mm copper pipe feeding an outside tape at one end of the house. I've not measured it but it has to be 7 or 8 metres long. It is fixed at both ends by soldered elbows on the outsides of brick/blockwork at both ends. there is one compression fitting halfway along. What concerns me is what may happen in low temperatures. The pipework could contract quite considerably and no doubt pull the compression fitting apart. I had thought to put a contraction loop in the run in the form of a push-fit flexible pipe in a very slight "S".

I can drain half of the pipe quite easily but that won't remove the contraction problem and if anything might worsen it.

What are the professional thoughts?

HyFy

 

[AWheating]

is the pipework clipped along its length? Is it lagged? how long has it been there?

if its been in a while it will probably be ok, if you leave the water off then if anything happens you wont get any damage or a large bill

welcome to the forum.

 

[Dannypipe]

That is quite a long run of pipe, and compression fittings do pull apart quite easily when the pipes freeze.

As said, as long as you can drain it, and leave one end open, I don't think you'll have any issues.

 

[SimonJohns]

You'll have about 1/8" movement on that from freezing to 25c. I wouldn't worry about it

Lag it. And drain it

 

[HyFy]

Thanks for the information. I will do as you all suggest. It is lagged and clipped along it's entire length. It's been there for, I guess, a couple of years but the previous owner did not leave the house in the winter with low level heating as I intend to do.

I would drain everything down but I don't want the hassle of refilling etc immediately I get back from an 800 mile drive!! A neighbour will monitor things.

HyFy

 

[Kev the gas]

How low is low level heating ?

I would imagine your house insurance would require at least 18 degrees?, if the house is left unoccupied in the winter.

 

[SimonJohns]

Fit a sure stop. Excellent peice of kit and can just be turned off.

It won't drain but it won't leak either

 

[HyFy]

Thanks Kev

I will ask the insurers. If they want 18 deg C on an unoccupied house for two months, I will drain down. I can't even guarantee 18 degs whilst we are here!!!

Thanks

HyFy

 

[HyFy]

Thanks for the advice about the Sure Stop. It seems a good piece of kit but the existing stopcock seems to be alright.

Thanks

HyFy

 

[Kev the gas]

Please do not forget central heating is not only for comfort.

Buildings also like a bit of heat to combat damp ect.