HOW TO REMOVE ROOF STAINS
To see an immediate improvement, you’ll need to climb onto your roof, spray it with a cleaning solution and rinse with water. A cleaning solution and water will remove most algae stains right away, but some can be especially difficult. If you have a steep roof, it’s best to call a pro. Here’s how I cleaned my roof.
1. MIX A HOMEMADE SOLUTION
To save money, I opted to make my own solution. Commercial roof cleaners are available at most home centers, but they’re expensive and won’t work any better than a homemade solution. Plus, it’s easy to make your own. Mix 15 oz. of an oxygen bleach powder (I used OxiClean Stain Remover, available at home centers for about $12) with 2 gallons of warm tap water in a garden sprayer. Don’t use chlorinated bleach; it’ll kill the lawn and plants on the ground below.
2. SPRAY THE SHINGLES Once you’re on the roof, start at the edge and spray the shingles with your homemade solution, working your way up to the ridge. A wet roof is a slippery roof, so leave a dry path back to your ladder. Allow the solution to sit for 20 minutes before rinsing. Tough stains may require an additional application and a mild scrubbing with a stiffbristle brush.
3. RINSE WITH A GARDEN HOSE
After you’ve waited for the solution to do its work, douse the roof with a garden hose, clearing suds and algae off the shingles. You’ll see a big improvement unless your stains are especially stubborn. Never use a pressure washer to clean the algae; the roof will be clean, but its life will be shortened by the loss of granules.