I wish to build two stone veneer column bases.

Existing is a 24 inch by 24 inch concrete base extending above grade.  In the middle of this bases is an additional 8 by 8 concrete block on top of which is an 8 by 8 wood post.

I expect to build a framed box extending up from the 24 by 24 base, around the 8 by 8 post, with pressure treated lumber.

What would be the prefer shealthing to cover teh box with and to which stone veneer will be attached?

Plywood covered by two layers of tar paper and metal latah?

OR

Cement Board?

I know wonder board says it can be used in exterior applications, it seems like that should go without say?  But perhaps soem cement board is to porus and pron to freeze thaw issues?

I have heard people say not to use cement board.  WHY?

Wood is always pron to rot, but most stone veneer is applied over wood and even OSB although much has been written abotu the folly.

Thoughts?  Experience?