Matthew,
Thanks for detailed drawings. I believe those are very useful for each involvements and they will clearly understand what you need.
Napat,
Please advise on Viva board technology then, we can also advise to James based on your Viva board conditions.
For the size of Viva board, James has finalized to use 1220 * 2440 * 12mm thickness for both Plain and stone pattern.
James,
I think you need to review what Matthew sent and provide Felt Paper and Drip edge if required upon Napat's advise.
As I said earlier, IGS planed to use Stucco materials as Exterior wall finish and the Stucco is breathable and is good for moisture maintenance.
In fact that CAF needs air gap, you should think about it when Viva boards do not meet its satisfaction.
Regards,