So you’re finally ready to hire some professional roof cleaners.  Your spouse is complaining that the black roof stains are ruining your curb appeal, and after reading through this site you now understand that it’s also an issue of your roof’s health and longevity.  Now you need to know how to find a roof cleaning company that will do the job right.  Here’s a general checklist for what to look for in a contractor that cleans roofs.

* First and foremost, you would be wise to find a roof cleaning service that uses non-pressure methods for roof stain removal.  If you’ve been digesting the other reading material on this site you should know by now that high-pressure roof cleaning is generally not a great idea.  The only rare exception could be in situations where there is very thick green moss like a carpet on your roof, and even in this extreme situation the pressure should be used carefully and responsibly.  Educated roof cleaners know that in the vast majority of cases, black roof stains can be completely and safely removed with the gentle application of a bleach or chlorine-based solution followed by a non-pressure rinse.  If you come across a contractor that wants to clean your roof with a high-pressure wand, run in the other direction as fast as possible. * Find a roof cleaning service that operates in teams of two on every job.  Theoretically, a roof cleaning could be done with one person, but the ideal scenario would be to have two roof cleaners on site for your job, one to apply the chemical and do the rinsing at the roof level, and the other to remain on the ground for perimeter rinsing and just as a “safety valve” in case the roof-man needs assistance.

* Roof cleaners that have been in the game for any length of time know that your whole roof should be cleaned, not just the areas where black stains are visible to the naked eye.  If you can see stains in any one area, that’s usually an indication that algae is already taking hold over your entire roof and will just require a little more time to become completely visible everywhere.  Best to clean the whole thing and start with a clean slate, so to speak.

* Ask to make sure that the contractor has liability insurance.  This one’s a no-brainer for any home improvement job, of course.  It not only protects you but it helps to weed out the handyman types who probably don’t understand the proper methods for roof cleaning to begin with.

* Though this last one isn’t a necessity, you might check to see if the roof cleaneris BBB accredited.  If so, that’s usually a good sign that they have been around for awhile and are truly knowledgeable about roof stain removal.  If they aren’t a member of the BBB then ask for a few references that can vouch for them.  It’s also a good signal if they have their own before and after pictures to show off, either on a website or in a portfolio.