I've just removed a big set of brick and concrete steps leading up to the back door of a c.1900 London terraced house to help with internal damp problems. Now I'm having to deal with the travesty underneath.
A lot of the cement mortal has chipped away nicely, and I think I'll be able to repoint what's underneath with lime without too much hassle (famous last words). The issue are the large patches of cement mortar as seen in the photo. It's different from the rest of the cement mortar hidden by the steps, so I'm assuming it was done to patch a big crack.
Where I have chipped away at it, the mortar has completely failed, like all the way through. I'm slightly more apprehensive about attempting this and wondered if anyone had any advice for "full-depth repointing". And sure, if you want to let me know whether you think it's a big subsidence crack, go for it. Thanks!
Edit: to turn this vague request into a question: how do I go about this? Do I go brick by brick?Terrified the bloody wall will fall apart.