Running copper pipes under a slab

Robert O'Connor

I need to run some copper pipes in a slab to get to some baseboard that I have to install.

I'm using soft copper tubing because I'm not comfortable running Pex at the high temps I need to make the baseboard perform.

I'm going to use 3/4 soft copper and sleeve it with (? size) black plastic pipe. I will be running about 20'.

Any comments or suggestions.

Thanks as always,

Robert O'Connor

hr

Are you sure, Robert

that we can't talk you into some Pex al Pex? Kitec, Weil McLain, Wirsbo? It can handle the heat!

Alright, if not 1/2' copper easily fits inside 1" pex. Would 1/2" handle the load? It can easily move 15,000 BTU/ hr.at 20 degree delta T.
Wirsbo offers pex in straight lengths, pictured here. I would consider straight lengths of copper also. Soft coil copper is a drag to solder fittings on (egg shape) and hard to make short turns with. Seriously consider straight lengths, type K, and silver solder any joints that are under ground.

You could sleeve pex in pex for a removable condiut in the rare case of a tube failure. 5/8" pex easily fits inside 1" pex. 5/8 can handle enough btus for most baseboard applications.

I have heard also that putting copper in a sleeve can actually accelerate concentrated area corrosion attack, if some weirdness gets inside flux, agressive ph water, etc.

If you absolutely need 3/4" copper proabably 1-1/4" PVC would be the best sleeve material. A bit of insulation around the copper and a 2" sleeve would help the heat loss to the ground also. Unless of course a strip of radiant floor would appel.

Stay away from foam pipe insulation, it's not great in the ground contact, insects are attracted to it, especially when it's warm and cozey

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Robert O'Connor

thanks

Thanks for the reply. You have given me some excellent input. I just like the proven durability of copper. I might be just a little bit stuck in my ways too!

Regards,

Robert O'Connor