Brick Cleaning

Submitted to Product Chat

We have pressured washed the large brick wall that surrounds our backyard, as well as our house. It gets the brick clean, but wondered if there's a cleaner we could spray first to lessen the amount of time the pressure washer is hitting the brick/mortar. I also want to be sure I don't apply something that will weaken the mortar. We have some black area on the brick, and those take more pressure than I like to remove.