For those who are into cutting corners, the idea of avoiding a thorough exterior scrubbing before painting is tempting. I mean, you're going to literally paint over any dirt or grime -- no need to change your spaghetti sauce-stained shirt if you're just going to wear a jacket over it, right?
Unsurprisingly, washing off the built-up dirt or paint residue is not just an unduly complicated step in the painting process. It's also a necessity for ensuring the paint job adheres well. New paint won't cover filth for long. This critical step rinses away any mildews or molds that have developed on the old paint, too [source: Hurst-Wajszczuk]. A good pressure wash is essential to that dream of a 12-year paint job. Do a merely superficial rinse and you're not giving your new paint the clean canvas it needs. Rent a pressure washer and don't look back.