Professional service is strongly recommended for safety, effectiveness, and warranty protection. Roof work involves significant fall risks, and many homeowners lack proper safety equipment and training for working at height safely. More critically, using wrong cleaning products or methods can damage shingles, void manufacturer warranties, or accelerate deterioration. Different roof materials and growth types require specific approaches that most homeowners aren’t familiar with. Professional roof cleaners carry proper insurance, use manufacturer-approved methods, and have experience identifying potential issues before they become expensive problems. When you factor in safety risks and potential damage costs, professional service typically provides better value than DIY attempts.