Securing concrete floor with heating

[maaats]

Testing my questions here as well.
Links to the forum thread:
http://www.byggahus.se/forum/grund-...lder-baerlager-under-cellplast-isolering.html

The picture at the bottom of the page contains my most current ponderings. The thread above also includes camera pictures and explanations for questions.

Plastic against the old concrete and against the "wooden wall"? (the blue one)
Which fabric on isodrän? (red)

Suggestions? Preferably someone who knows, I can guess myself
Thanks