Best pipe for external plumbing?

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prv

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The garden tap on the outside of my house is in a rather inconvenient position, so I want to move it five metres or so along the wall. The existing pipe is 15mm copper, emerging from the wall just above ground level and running upwards to the tap.

What kind of pipe do people think would be best to extend it - traditional copper, or one of the plastic systems? The location is fairly sheltered, being a narrow gap between the house and the garden wall.

Is copper or plastic more prone to freeze damage? I'll fit an isolator at the start of the run, but sod's law says I'll forget to turn it off for at least one winter. Is there any point to insulation around a pipe that's not used for months - surely there's no heat to keep in?

I'll fit the required check valve while I'm at it, though I don't think there's one currently.

Cheers,

Pete
 
Copper is probably more doable for the handy man with fittings that can be self soldered. I think the plastic pipes need a special swaging tool to connect to copper. Sorry no idea on freezing. Never seen a frost here. ol'will
 
Pete

The only thing I'd worry about is PVC piping "food grade". I've always considered it unsafe but when I google now I seem to get conflicting opinions.

Clive
 
William_H said:
Copper is probably more doable for the handy man with fittings that can be self soldered. I think the plastic pipes need a special swaging tool to connect to copper. Sorry no idea on freezing. Never seen a frost here. ol'will
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Plastic pipe with push fittings the easiest IMHO.

Insulate ? Yes . Will protect against short freezing spells if not against a prolonged penetrating frost. Not often that severe in south of UK esp in coastal areas.
 
coopec said:
Pete

The only thing I'd worry about is PVC piping "food grade". I've always considered it unsafe but when I google now I seem to get conflicting opinions.

Clive
Click to expand...

Water mains and incoming pipework these days all plastic. The blue pipe you see at the roadside everywhere. but I doubt if food grade would be necessary for a garden tap. I guess that's used for watering the garden!
 
Vic
"but I doubt if food grade would be necessary for a garden tap. I guess that's used for watering the garden!"

Yes, I missed "garden tap"

In Western Australia these days all lots in new sub-divisions have two water supplies - untreated bore water for garden taps, toilets and swimming pools and treated water for kitchen and laundry.

(I've got PVC external plumbing for indoor water supply but I'm assured it is food grade.)

Clive

Just a further thought: I used to fill the dog's bucket of water via the garden hose until I read it is a definite NO! NO! (Apparently it can cause brain damage inter alia in the dog)
 
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Perhaps a hose tail extension with a ball valve on the end would be more practical. Les prone to bursting and easily removed in the winter. The ball valve could just be hung off a hook at the more convenient location.

If the permanent extension is what you want, and as it sounds like it is not that visible, then I would use plastic pipe and push fits to extend.
 
The various plastic barrier pipes you get for plumbing now is all suitable for potable water, and if you're worried about frost, plastic may be the way to go. It can still freeze up, but generally that stretches the pipe, rather than splitting it. The pipe still needs to be replaced, but is less likely to leak catastrophically when the ice thaws. Not a huge consideration for outdoor use, but worth bearing in mind.

If you use pushfit fittings, make sure you use sleeves inside the (plastic) pipe and try to use easily demountable fittings like JG Speedfit, rather than the more awkward to replace PolyPlumb, in case you do need to take it apart. If putting the plastic pipe into normal compression fittings, the inner sleeve is also required on the pipe, else there is nothing for the olive to compress onto.
 
The only other consideration regarding plastic pipe is that it needs clipping to the wall at more frequent intervals than copper and suffers more thermal expansion and contraction which sometimes leads to unsightly sagging of the pipe between clips.
 
All plastic pipe for water will have been passed by WRAS which means it is safe so no tinfoil hats needed.

Plastic pipe can sag when its warm and doesnt look pretty so i would suggest copper pipe. There is a range of fittings available from B n Q, others available, there are some very good copper fittings that are push fit, you do need a special tool to get them apart so only connect when all sorted. and yes it should all be insulated.

I installed one in a new build i did last week, started with an isolation valve then 10 meters of pipe out through the wall then dropped it down to the bib tap, so in the winter the valve can be turned off the tap left open and it will drain down so no risk of freezing.

Do remember that any outside tap should have a double check valve fitted in it to comply with water regs
 
Plus as it may have plastic below ground a separate earth supply is required i believe.
i was pulled up years ago by electric supply co because outside tap fitted to plastic pipe was not earthed. No idea if regs not changed though. Perhaps some one electrically charged can comment
 
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I've used copper above ground for outside taps, supplied by blue plastic underground pipe. I've insulated the copper with ordinary foam pipe insulation inside a larger diameter plastic pipe. If you're very worried about freezing, you can add low wattage trace heating connected to a frost-stat - I did this when I put automatic drinkers into the stables, and it works well.
 
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