The key to a clean roof is effective mold removal and mold prevention. Mold is what makes your roof look dirty. It also a living organism. Tiles are also porous. Each time your power wash house roof tiles you make them more porous. This gives mold more places to grow, multiply and expand on your roof (which may explain why you seem to be power washing more these days! When it rains mold falls from the roof to your driveways, sidewalks, decks and patios where you track it into your home.. Klean Roof uses a gentle approach when roof cleaning. Our effective and progressive cleaning solution kills mildew and mold instead of just blasting it around your property. We use low-pressure technique that protects your roof with more progressive methods. Our effective roof cleaning solution eradicates all mildew,fungus,mold and algae,including microscopic spores. Applied using a low-pressure spray,similar to a garden sprayer (30 PSI) and unlike high-pressure devices (3000 PSI),this method allows your roof to sustain its intended lifespan. This method allows your home to live out its intended lifespan while continuing to protect and kill mold and mildew for 3 years. This process is very effective on cement tiles,asphalt shingles and metal roofs.