There is a joint on the foundation wall between the existing house and an extension (3-4 years old). What is the best way to fix it? On the left in the picture is the old foundation, concrete hollow blocks that are directly on rock. On the right is the extension's foundation, which consists of 350mm isoleca blocks with plaster on the outside. The Lecablocks are on a concrete slab.
What is the best thing to do? Should I just knock away what is loose and plaster over it again and hope it doesn't crack again? The extension should have settled by now.
Or should there be a vertical movement joint? What do you make such a joint of if so?
What type of plaster mortar is best for this kind of repair??
