[6stringmason]

Im doing a column outside for my wife's cousin and her husband. They have the column already built. 2x2x3 and have it covered in cement board(masonite).

Do you think I should wrap the corners with metal lathe? Or will expansion not be a problem with this stuff?

[tkle]

Not a problem.Hope they have the rougher side of the board exposed.
I use extra glue with the board.I've never had a problem with it,but I don't trust it.

[laybrick]

what would it take to throw a piece of mesh up to avoid any problems ?

[laybrick]

or doubt you may have

[tkle]

...or paper and mesh to start with.

[stacker]

i would play it safe and wrap the corners with lath.15-20-30 mins to do it and you wont have to worry.

[stuccoman]

All outside and inside corners should be wrapped with lath. And where freeze and thaw cycles happen often a moisture barrier would not be a bad idea.