[Hardwood Head]

I have an exterior wood framed wall that is secured to a concrete slab with a Pressure treated bottom plate. I am going to wrap the wood framing with Tyvek and then install 1" exterior ridgid foam and then finish with a layer of 1/2" concrete board. Am I ok to parge directly on to the concrete board or is there a need for a mesh to strenthen and bond the pargeing compound? Can I use a plastic corner bead on the exterior outside corner?

[hand drive]

Your best bet is to use a row of block to make the concrete to concrete water tight seal and build the wall atop of the block, then run you 1/2" board over the block if you do not want to see the block.