First Wright house with radiant floor heating

[ozwrightfan]

The weak point of any tubing system would in most cases be the joins.

[SDR]

Indeed -- as is the case with every joint in any building -- and in particular joints between dissimilar materials. So we were reminded as very young
students of architecture.

Speed of assembly is of increasing interest throughout the building trades. I am impressed by the number of improved fittings that I see demonstrated
on the plumbing/HVAC segments on the building shows on TV. Dry fittings, sometimes accomplished with unique crimping tools, make quick work of
connecting elements of the new systems.

There is also a PEX tubing made with an integral aluminum jacket, intended to inhibit crimping as the material is fed into and through tight quarters.

SDR

[Paul Ringstrom]

There is also a newer product called PEX-Al-PEX which as it sounds consists of five layers, inside and outside layers are made of Cross-Linked Polyethylene (PEX) tightly bonded with melt adhesive to the mid-layer of aluminum.

The metal layer serves as an oxygen barrier, stopping the oxygen diffusion through the polymer matrix, so it cannot dissolve into the water in the tube and corrode the metal components of the system. It also bends better, because the shape memory of the PEX is offset by the aluminum.

Regular PEX is also available with or without an oxygen barrier as part of the polyethylene.

[SDR]

Interesting -- and more complex that I had any notion of. The PEX-Al-PEX is the one I was trying to describe. But I didn't understand the full uses of the metal layer.

SDR