I have never done exterior foundation insulating because I have never seen a good looking and long lasting finish. Even parging on concrete only lasts so long depending on the methods and materials in application. I have always tried to use new form ply where it had to look really good.
It is also the reason I have to done any styrofoam block foundations. I saw a reputable company do some parging over a mesh on the styrofoam and two years later it was all flaking off from the frost.
The only one I have ever seen look ok was a Pressure treated ply over the styrofoam. Problem was the frost pushed the plywood upwards and the owner had to keep cutting off the top edge every few years.
Anyone have any ideas?
thanks in advance, george