The first effective roof cleaning product without the harsh chemicals that can cause damage to your roof and kill surrounding vegetation. It's made of an optimized blend of detergents, coupled with a unique buffered chemical made from sand and soda ash, which is recognized as a non-pollutant. Cleaner should be applied using the applicator which automatically dilutes the cleaner 1: 6. Allow the cleaner to work for about 20 minutes and rinse away with the roof rinsing tool. The rinsing tool will speed the rinsing process without damaging the shingles. Some light spotting or streaking may still remain. The blocker will continue to work on this until they eventually go away. Defy Stain Blocker For Roofs. Once the roof has been properly cleaned and rinsed it should be treated with Defy Stain Blocker to prevent ugly stains from returning. Maintenance coats should be reapplied about every two- three years or at the first sign of the stains' return. Features: Model: 24654. Brand: SaverSystems. Accessories. Type: Roof Cleaner Applicator. Roof Cleaner Applicator.