Hello all, first time poster. I'm having a similar issue as the OP. Newer home under 10yrs old. Brick lintels are rusting and causing some very minor stair cracks in the mortar. In the process of buying a new home so we are prepping this one to sale. Or possibly to keep long term as a rental. Either way I want it fixed. Obviously not interested in tearing out the brick lintels around the entire house. If the issue is moisture going through the brick and collecting on the lintels why not paint the visible rust with rustoleum, and then seal the masonry to prevent water from penetrating the brick? Seems like a pretty obvious solution but I don't see any mention of it. I've used masonry sealer on previous projects and it works like a charm. Why wouldn't it work in this situation??