What Should Pex Not Be Installed in?

PEX can't be installed in high heat areas.

You can't install PEX in high heat areas like near recessed lighting. This also means you can't connect PEX directly to a hot water heater, but you can use a connecting material to do this.

Can I run PEX in conduit?

Yeah just put a hole a few inches in on the PEX and put tie wire through it and pull it in like electrical cable. Soap it up good on the way in. It should go a long way if your strong enough.

Can you run PEX through joists?

The Advantages of PEX

You can snake long runs through joists and studs. Second, PEX doesn't sweat under high humidity conditions, and it's also resistant to bursting, even if the lines freeze solid. Third, joints are easier.