Common outdoor surfaces:

• concrete
  
• brick
  
• pavers
  
• flagstone
• rust
  

Areas around the house:

• driveways
  
• walkways
  
• patios
  
• balconies
  
• fences
• hard-water buildup
  

Common stains:

• dirt
  
• algae
  
• mold
  
• oil and grease
  
• drink spills
• abrasive wet-sandblasting
  

Wash Techniques:

• cold-water
  
• surface scrubbers
  
• industrial degreasers
  
• acidic cleaners
  
• and more