Lilly Miller Moss Out Moss Killer Concentrate 27 ozOn outdoor structures, damaging moss can grow in nearly any location where dampness persists. Controlling structural moss may add years of service to roofs, decks and walks. Liquid concentrate moss out spray kills moss and algae within hour on patios, driveways, sidewalks and roofs, yet it won't stain bricks, concrete or asphalt. Non staining formula can be used on roofs, cedar shakes and composition shingles, cedar siding, stucco, cedar and redwood