Stucco Sealing- Casa 2G

[MFarruggio]

I'm sealing the modules at this point and have the stucco & lath for after the insulating. With the oven's exposure to our winter rains and stucco's permeability to water, Should a waterproofing additive like a latex be used? or should a sealer be applied to the regular cured stucco? We plan to mosaic the exterior with thinset and ceramic pieces. Also with the the higher heat near the arch I was wondering if anything is reccommended for that?

Being a DIY-er I know enough to be dangerous and any good knowledge is really appreciated.

Thanks!!

Matt