Compressive strength of Isodrän or foam plastic under foundation wall

[Voh]

Feel free to check out husgrunder.com, they have some useful information, including about köldbryggebrytare.
http://www.husgrunder.com/ny-husgrund/gjuta-betongplatta/

Tjällden also has good descriptions
http://www.tjallden.se/produkter/platta-pa-mark-villa/

Perhaps there are special versions that allow for thinner walls as well, but nothing that I'm aware of. On the other hand, I am not experienced when it comes to foundations.

 

[KnockOnWood]

OK, now I understand what you're getting at!
To quote Tjällden's description

The thermal bridge breaker should always be placed under the outer wall, as otherwise, it risks protruding through the concrete slab.

I see this "risk" as pure nonsense.
If the foam might stick up a bit, it is not a problem.
Foam (=Styrofoam) is very easy to sand down.
And if the floor has a little less load-bearing capacity centimeters nearest the outer wall, it can't be the end of the world, right?

I would actually be more worried if the edge beam does not support the entire sill/rising timber,
and the wall partially stands on foam.