• In this video, This Old House general contractor Tom Silva explains how to remove roof moss.


    1 Slide a margin trowel under shingles to unstick them from the ones below.
    2 Slide sacrificial zinc strip underneath the loosened shingles.

    3 Secure the strip with roofing nails.
    4 Apply a dab of sealant to every nail head and run a bead of sealant under each shingle.
    5 Continue installing zinc strips across length of roof, end to end, leaving a 1/8 in. space between the strips.
    6 To kill existing moss and lichen, make a cleaning solution of equal parts bleach and water.
    7 Protect nearby shrubs and lawn with plastic tarps.
    8 Spray the cleaning solution onto the shingles using a garden sprayer.
    See products and services from this episode.
    • Difficulty: Easy to moderate
      Getting up on the roof is the only difficult part.
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      Video Directory

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      Tools List

      • margin trowel
        Margin trowel
      • hammer
      • caulk gun
        Caulking gun
      • ladder
      • garden sprayer
        Garden Sprayer

      Shopping List

      1. Zinc strips

      2. Roofing nails, for attaching zinc strips to roof

      3. Tri-polymer sealant, used to cover nail heads and seal down shingles

      4. Plastic tarps, used to protect nearby vegetation from bleach solution

      5. Chlorine bleach, mixed with water to kill existing mold, moss and lichen