I am renovating an 1870s house in MA and started by gutting a small bedroom on the 2nd floor. After insulating, I plan to install blueboard with veneer plaster. I have read DIY books, Building codes and these discussion groups but I cant figure out whether I need 5/8" or 1/2" blueboard. I guess it depends on local building codes and where the room is located, but I am wondering what the rule of thumb is? 1/2" blueboard is readily available, while I would need to go to a commercial dealer to get 5/8". Which brings up another question....does 1/2" blueboard/sheetrock plus the 1/8" veneer count as the 5/8? Any thoughts would be appreciated.
Thanks
Joe