Outdoor shower

[TonyW2]

Yes, that's fair enough.

 

[oldbuffer]

I've done exactly what you want to do for a customer, who wanted it for the same reason.

All the gubbins (TMV, check valve, drain off, isolation valve) inside. Slight downward slope to pipe through wall with bibcock on end, so in very cold weather it was turn off the indoor isolation valve, open bibcock to drain water.

 

[tuppence]

so in very cold weather it was turn off the indoor isolation valve, open bibcock to drain water.

In this case, the wall is a south facing cavity wall with 2” insulation and normal room temperature inside. There would be no exposed pipework and no compression joints. How cold would it have to be to burst the pipe within the wall?

My reluctance to install an isolating valve is simply that draining the pipework in really cold conditions would compromise the aim of having the shower available from outside at all times, particularly in winter.

Would protecting the tap with an insulated cover when not in use be an adequate alternative?

 

[Madrab]

I would still have ISO's on the feeds to the mixer though if for nothing else than allowing it to be isolated for servicing. Yes an insulating cover will be of use to protect the tap. You would need extended below freezing temps to freeze back into the wall, so it's pretty unlikely where you are but never say never, it's always worth putting protection in just in case.

 

[tuppence]

I was looking for other solutions to this problem when I stumbled on so-called frost proof faucets (aka frost proof sill cocks).

The principle is simple: the body of the tap is a 3/4” tube that passes through the wall. The mechanism is protected from freezing by being at the indoor end of the tube and a concentric rod connects it to the operating handle outside.

Provided the tap is installed with a downward slope and the outlet is not obstructed, water will automatically drain from it after use. The mechanism stays warm all year round and only an empty pipe freezes in winter.

http://www.acehiplumbing.com/blog/wall-faucets-eastman-and-woodford-model-17-model-19/

So why isn't this kind of outside tap generally available here and more to the point, is there any problem with installing one in the UK?

 

[Madrab]

It isn't WRAS approved for use on potable water. It's American and probably hasn't reached here or it has failed approval for a certain reason, not sure if it would prevent backflow under certain conditions, UK spec is usually different than US.

It really is what you would do here anyway, slight downwards angle when pipe installed and an iso valve inside. Shut that down & open tap to empty with a double check valve in between.