Soldering copper tails in modern houses.

[MickBrown]

A lot of modern houses have plastic pipes with copper tails, so behind the plasterboard would be a pushfit fitting with a rubber seal. If the copper tails need modifying then how close to the push fit fitting could you solder without heat transferring along the pipe and damaging the seal? Attaching a heat sink to the pipe would help to stop the heat transferring but interested to know what others do?

 

[nysk2008]

depends how close the pushfit/rubber seal is to the soldered fitting. done loads od these and genally heat tranfer is not a prob, direct heat is the prob. Closest i have worked is about 300mm away and itn has been fine

 

[WaterTight]

It's a good question. Not in terms of how can we know how close we are allowed to solder because all manufacturers of plastic pipe and fittings do have specific distances you're allowed to solder from their products (I don't know them from memory but someone here will post them)

The reason it's a good question is quite often you won't know what is in a wall or under a floorboard you'd rather not have to try and lift. So do you take a chance of do you use compression?

 

[Best]

Even if you were, say 300mm away, if you heated the fitting/pipe for a bit too long, the heat would transfer far & be severe. Plastic pipes would need well clear. Glad I don't use them. :smile:

 

[jtsplumbing]

Try useing the slim copper tactight fittings (pushfit) a bit pricey but can get you out of a spot.

 

[Guest123]

The minimum distance to make a soldered joint near Speedfit pipe or fittings is 450mm. Anything less and the heat can damage the fitting even if not immediately apparent that it has. Flux will completely destroy a O ring in a push fit fitting. Use a good quality compression fitting like Kuterlite instead. Using solder and flux at 300mm is far too close.
Here's a useful link for future reference. Download it and put it on your Smart phone or Laptop:
http://www.cabp.co.uk/acatalog/speedfit_guide.pdf

 

[AWheating]

from memory most manufactures recommend between 400 to 600mm. Both the speedfit and polypipe reps that used to visit the building sites i worked on a few years back would tell me 500mm min.

if the 1st fix was done correctly then you should be fine, but thats a big IF. Normally when i have first fixed with copper tails to rads and sanitary i cut a 3m length of copper into 4 so i always leave 750mm min.

 

[Best]

Went to a burst 22mm Hep pipe recently. Boiler control stat had failed & flow pipe from boiler, about a metre away, had swollen in two places & split at one of them. If this can happen with hot water, then blow lamp heat would be worse.

 

[Guest123]

There are a lot of older houses that have domestic hot water systems running at well above 65 degrees which is the recommended maximum for most Speedfit pipe and fittings. Had one blow into orbit last year, even though it was 100% fitted correctly. The heat was a factor from the ancient hot water system. I rarely use it now and certainly not without a TMV.

 

[Dannypipe]

If I'm concerned about heat travelling down the pipe and onto a plastic fitting. I will soak a rag, and wrap it around the plastic fitting and the pipework, or as close to it as I can.

Not a sure fire way to avoid heat transfer damage, but it will cut the heat transfer down.