Laying brick and cleaning them are, in fact, all part of the same skill set. This is like saying the chicken in your pasta, or the sauce, is a different skill than what went into cooking the pasta. Your analogy is more akin to someone putting a potted plant on the wall. No one is going to care if you put a potted plant on the wall. But if you damage it, because of messing with the joints, I’m sure they won’t feel very compelled to honor a warranty. That does remind me, I should put a clause in my contracts that says this. If you grind away all the binder from the joints by brushing away the lime and portland, leaving exposed sand, and water gets in because of this, that’s on you.