PEX piping is the biggest revolution since the flush toilet. ... If you use a manifold and ‘home-run’ system, ... First extend a pipe 18 in. from your water heater and connect the PEX to the pipe.

PEX water piping is much like electrical wiring. It's flexible, and you can run long lengths of it from a central distribution manifold all the way to the plumbing fixture without any joints.