Hey, now this is something I know a little about!
Pressure Washers are probably one of the most versatile groups of contractors on the planet. I've seen guys up-sell everything from tree service to Christmas lights. To me it really shows the ingenuity and work ethic of our group. There is an endless number of other services you can offer as a PW contractor, but the key is to offer services that utilize the skills and equipment you already have. Don't forget you are a cleaning contractor, and you are probably pretty good at it. There is another side to our industry, that most guys don't ever get a piece of. It's what you can offer the customer after the cleaning that's the real $$ maker. No matter what you are cleaning, there is almost always an additional service you can offer them. Whether it is concrete, wood, pavers, brick, block, stone, etc... All of these surfaces need to be protected, and many times the customer is also interested in changing the color or appearance of the surface. Think about offering services like concrete sealing, deck staining, stone sealing, concrete staining, epoxy floors, etc. These are services you can offer right now to your existing customers. Think about it, you've already done the hard part when the cleaning is done. Why leave the other half of the job unfinished?
I actually wrote an article in the June issue of e-CLEAN about this very subject. Check it out at
http://www.ecleanmag.com/past-issues