When someone is looking to find an exterior cleaning contractor for their home or commercial business. Of course you want to do your due diligence check out their reviews. Ideally, you want to make sure that this is not a window cleaner or a gutter cleaner who's branching off and trying something new as far as exterior cleaning and restoration roof and building exterior and hard surface cleaning. Those are specialties. You want to make sure that that company has experience. Providing that service. Ask to see examples of their work. Ask to see examples of their work in your area. Ask how long ago they provided that service, so you can see the examples of their work, but how long that service lasted and how it looks today.