We were asked to make good around these French doors but with the builder using a steel catnic rather than a RSJ , this would be one of many problems we would have to over come.
we had to change our standard procedure to something very different.
Using a very strong resin based adhesive we stuck a light weight render carrier board over the steel .
Using light weight high polymer render we bedded mesh into and around the door to prevent any cracking then applied the render to thickness of the beads using a rule to check for flatness and any hollows on the wall.
Using a fine felt sponge when the material was ready we blended our render into the existing .