Many folks think that brick, block and stone walls, whether they are part of a structure or stand alone retaining walls are maintenance free. This simply is not the case and you must be sure to inspect these surfaces once each year and take action if necessary. Look for chipped surfaces, and discolored coating, because this can be a sign of excessive wear, thus you need to find the source to stop the rapid deterioration. It is akin to the enamel on teeth, as the teeth are safe if they are kept clean and not eroded by acid or sugar.
When you think of brick work or stone think of it in this way. Many stone driveways are coated, but overtime that stone coating can come apart, scraped, scarred or deteriorate from chemicals, oils, fluids or acids. It is wise to clean and pressure wash such surfaces by in doing so, not pit them or cause surface coatings to be removed. Brick and stone are used because they are superior building materials that can last for years, but nothing is guaranteed if you do not take care of it. This is why you need to inspect the block, brick and stone surfaces around your home and keep them clean.
Indeed, I recommend using a 45 degree tip at the end of a 2000 psi pressure washer at least twice per year. Depending on the climate changes and seasonality extremes maybe more and be happy to know that this is the kind of job you can do yourself with a home pressure washer, without paying out an arm and a leg.