How to Kill Moss on Rooftops

Rooftops in humid, densely vegetated climates typically acquire moss, a cushiony plant lacking roots. Roofs with inadequate drainage are also prone to moss, as the plant spores require moisture to grow and reproduce. While moss may give rooftops fairytale charm, the green growth rapidly proliferates and thickens until it eventually obstructs rooftop water drainage, causing interior leaks. Moss may also grow underneath roof shingles, forcing them to loosen and protrude. Since moss is capable of causing a good deal of roof-related damage, promptly kill the springy growth before it worsens.

Things You'll Need

• Plastic drop cloths
• Chemical-proof gloves
• Protective glasses
• Slip-resistant shoes
• 10-gallon bucket
• Stirring utensil
• 3 lbs. zinc sulfate powder
• Pump sprayer
• Push broom

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Instructions

1. • 1

     Choose a calm day to kill the moss. Drape plastic drop cloths over all plants and other greenery below the roof line.

   • 2

     Put on safety gear, including chemical-proof gloves, protective glasses and slip-resistant shoes.

   • 3

     Fill a 10-gallon bucket with 5 gallons of water. Stir 3 lbs. of zinc sulfate powder into the water. This amount of solution will cover 600 square feet of rooftop.

   • 4

     Pour the zinc sulfate solution into a pump sprayer. Spray the mossy rooftop evenly with the zinc sulfate solution.

   • 5

     Wait three weeks for the moss to turn brown and die. Do not rinse the roof.

   • 6

     Brush the dead moss off the rooftop, using a push broom.