When choosing a doctor where would you go? Would you seek a medical professional from the backroom of a grocery store? I hope not! When you choose an exterior service provider you have to be equally cautious. Only, the professionals will know what to do! How do you tell who the professionals are?
A professional company will be licensed and insured! If a company doesn't have these two credentials run away fast! This proves they can't cover the damages they are about to potentially create on your property. This can result in lifted shingles or holes in siding, even electrical short circuits. The sky is the limit with these unprofessional "pressure washers." Make sure they have these credentials.
Professionals will seem to have a more extensive knowledge on their services because they have learned and gotten the proper education. If they sound like they don't know any more than you do about the service, then the chances are they don't! Just like most services pressure washing and exterior cleaning service providers have classes and education in place as well.
Professionals will look professional! When a service provider comes to your home or business they will look the part. They will be dressed as a group typically in matching shirts. Yes, this doesn't necessarily include coats or personal accessories. Typically they will have bleached spots on their shirts as it is nearly impossible to pressure wash and not get bleach on them at some point! This one isn't a sure fire way to tell a professional, but I believe it is an easier way!
Look at their reviews and do your research! If they have great reviews for the most part and very few bad reviews then chances are they are a great company. Everyone gets bad reviews so a few bad reviews are ok but if they have mostly bad reviews and little to no good reviews it probably just isn't the right option. Do your research!
A professional will have a clear idea of what is going on! They will inform you of every complication faced and inform you of what their solutions are. They will be up front and honest with you about every step being taken.
Number 6 and the most important if you just get a bad feeling about a company don't choose them! In my opinion, you should never go against your gut feelings. If you are uncomfortable with a service provider there are plenty more around that might make you feel better.
Your home will thank you!