I have a customer who wants use to use Brussels block stacked around the outside of the attached stairs and landing. The landing is pitched toward the outside edge where the wall will be. I am planning on a 8 in base of compacted ca6 and will have two courses of block buried. for the approx. 4 1/2 ft tall wall. What i am worried about is moisture getting behind the wall, freezing and causing it to fall. They want the brussels block stacked right against the landings foundation. Do I have any to worry about? They do not have the budget to teardown the stairs and start over. Does anyone have any other ideas to dress up the stairs?