Slate roofing – moss or lichen

Cause

Insufficient cleaning

Repair

  • clean roof using a solution of 1 part household bleach to 4 parts water and brush with a soft broom. Do not waterblast as this can force water up between the shingles.

Cause

The roof remains damp due to overhanging branches

Repair

  • clean roof using a solution of 1 part household bleach to 4 parts water and brush with a soft broom. Do not waterblast as this can force water up between the shingles.
  • cut  back overhanging branches