In the twenty-five plus years we've been painting I don't think we've painted an exterior without pressure washing first.
On the other hand, I've spent countless (and needless) hours because the painter before us failed to do so. As a painter, one's first principle should be the same as the physician's: First do no harm. Make your customer's home easier to paint the next time around. Not harder.
Is cleanliness next to godliness?
That would be a yes; that is, if Mom had any say in the matter. Well into her 90s, she trooped on: the house I was raised in was immaculate. It was her therapy. And although she never quoted the adage, her actions spoke louder than words. Cleaning became a kind of meditation for her, a compulsion you might say, but the act of it brought her peace.
I inherited that gene.
Neighbors would comment about this well-dressed woman, looking like she was going to the theatre by any Santa Barbara measure, raking leaves from the giant sycamore in the front yard of that same Muncie, Indiana home. That tree became her nemesis, her great white whale. You could argue that the tree was the reason she sold the house. That and her increasing difficulty in remembering how to find her way home.
The adage is true for painting as well.