Rehabilitation of a building constructed in the 1860's requires cleaning and repairing the existing brick exterior walls. The brick is in good condition but is very dirty. Portions of the mortar have fallen out, and much of what remains is so soft that it can be scraped away with a fingernail. Which restoration technique should the architect recommend
A- Pressure Washing with a 10% muriatic acid solution.
B- Pressure washing with plain water and repointing the mortar.
C- handwashing the brick with water and stiff brush and repointing the mortar.
D- Sandblasting