Simply put, avoid high pressure. Power washing a brick house could cause any distressed brick to chip or recede. This can be tricky because removing the surface layer from several bricks could create the illusion of cleanliness instead of damage.
Another thing to avoid when cleaning brick is to avoid acid washing or any acidic cleansers like ammonia. An acidic cleanser can eat away at the outer surface.
Soft Washing Brick Homes
Since high pressure is not safe for cleaning brick siding, the recommended route is using a soft wash method. Soft washing uses biodegradable cleansers that cut through surface contaminants. This is followed by a low-pressure rinse that effectively removes those contaminants and is safe for the brick. Soft washing is a specialised process and is best left to a fully insured professional power washing company.