Brick, old paint and the case for low pressure
Many houses in this part of town are brick, stone or painted wood, and some are close to a century old. Old mortar can be soft, and old paint may be thin or flaking. Strong pressure aimed at either one can cut into mortar joints, drive water behind trim or lift paint in ribbons.
Homes built before the late 1970s may also carry lead-based paint, which is another reason to avoid blasting a surface. We keep pressure low, let a cleaning solution do the work and rinse gently. If a surface looks too fragile, we say so and suggest leaving it alone or having a painter assess it first.
