Pex

[Rancher]

OK, PEX is the solution

Copper water pipe under the foundation is the problem, hydronic heating in the slab is why I don't want to go down and patch it.

The question is:

Why can't I just use regular barbed fittings with hose clamps on this PEX replacement, which is about 20', I could make both ends accessable, is there a problem with this?

This is the result of my leakage under the slab thread....

Rancher

[Rancher]

Nobody has tried this?

Rancher

[kordts]

Because PEX is not designed for barbs. Go with the manufacturer's spec's.

[Wet_Boots]

PEX is CTS-sized, for which they don't make fittings of the kind used with black poly tubing.

Understand that the Oetiker company makes crimp clamps for PEX (and the company knows about clamps) but their tools for PEX clamps aren't any bargain, so no great savings there.

You might find a thread about how one contractor uses a heat gun and a pair of worm-gear clamps to make repairs in PEX tubing in concrete slabs.

[Rancher]

You might find a thread about how one contractor uses a heat gun and a pair of worm-gear clamps to make repairs in PEX tubing in concrete slabs.

I have experimentally used a heat gun and barbed connector to see if it fit, just don't know the down side of doing that.

Rancher

[Wet_Boots]

If this is that 3/4 copper line in the slab, and you are able to use it as a sleeve for 1/2-inch PEX, then you can just use compression fittings on the PEX, and be good to go, if the fittings are visible. Sharkbites are supposed to be rated for behind-the-wall use.

[Herk]

Perhaps there's a difference in terminology among the posters in this thread. There is such a thing as PEX barbed fittings. The type that sweats onto copper would work, assuming Rancher knows how to solder a fitting onto copper.

I don't do hydronic heating, but I assume that the proper PEX for use here has an oxygen barrier - not the same as regular potable water PEX.

[GrumpyPlumber]

Perhaps there's a difference in terminology among the posters in this thread. There is such a thing as PEX barbed fittings. The type that sweats onto copper would work, assuming Rancher knows how to solder a fitting onto copper.

Wirsbo PEX

I don't do hydronic heating, but I assume that the proper PEX for use here has an oxygen barrier - not the same as regular potable water PEX.

Absolutely, you'd have a rust bucket for a boiler in no time.

[Rancher]

There is such a thing as PEX barbed fittings. The type that sweats onto copper would work, assuming Rancher knows how to solder a fitting onto copper.

Yep, know how to sweat a copper connection, I was amazed at the local lumber store (not big box) how hard it was to find the silver solder, they had lots of 60/40... wonder who's still using that?

OK back to PEX, I was talking the regular barbed fitting, didn't know they made a size for PEX tubing. So instead of buying a $300 crimp tool for a job that requires two PEX fittings, why can't I just use a screw pipe clamp, seems to me they both do the job, I realize that if you were doing an entire house they would be a lot more expensive.

Rancher

[Wet_Boots]

PEX is something closer to a rigid pipe than poly tubing is, so it isn't really intended for the same sort of clamping that regular black poly is. That Oetiker manufactures a series of clamps for PEX is an indication that one does not have to stick with only a single manufacturer's fittings and pipe and crimp rings.

If both ends of the PEX will be exposed, you can use PEX-specific compression fittings, which are inexpensive enough, and leave the question of worm gear clamps to someone else. Rest assured that no one is going to manufacture any PEX-specific worm gear clamps.

[Rancher]

If both ends of the PEX will be exposed, you can use PEX-specific compression fittings, which are inexpensive enough, and leave the question of worm gear clamps to someone else.

What is a PEX-specific compression fitting, is there one that doesn't require the special crimping tool?


Rancher

[Wet_Boots]

I used Qicktite compression fittings when I severed an outdoor sidewalk-defrosting line. Worked perfectly. Now that I look at a newer catalog page, it seems they're also approved for copper and CPVC and polybutylene as well, with about a dozen various agency approvals. About five bucks a pop for a Qicktite coupling or NPT adapter.

[jadnashua]

A heating supply place will have brass compression fittings for pex - just need a wrench. For a single fitting, not bad, but really expensive on a whole house remodel.