[Greenbuilding] [BULK] Re: PEX tubing

[Lawrence Lile]

>the expansion and contraction of the pex could crack
the slab.

Have you actually observed PEX cracking slabs?  Radiant floor in slab
has been a standard construction technique for dozens of years.  

Radiant floor companies sell a special tubing for this application, it
has an extra layer of plastic on the outside of the PEX.  They also sell
a tubing called PEX-Al-PEX, which is two layers of polyethylene
sandwiching a layer of aluminum.  This should last longer than the
already long-lasting two layer tubing.  The tubing comes in long rolls
to minimize joints under the slab.  

I would not recommend using hardware store tubing. 

--Lawrence Lile