If you have wood roof shingles, you may notice over time that they have become dark and stained. While you can’t turn back time, you can lighten stains and remove mold and mildew to make your wood roofing shingles look like they are in good condition. Regular cleaning will also help prevent debris from accelerating rot on your roof.
Step 1: Start by wetting the roof with your garden hose. When applying water to a roof, be sure to apply water from the ridge to the gutter. This will prevent water from working its way underneath the wood shingles and causing a leak.
TIP: Avoid using a pressure washer for this project, which could inadvertently damage the roofing shingles or force water into the cracks between shingles.
Step 2: Mix your cleaning solution by combining 1 gallon of hot water with 1 quart of chlorine bleach plus ¼ cup of trisodium phosphate.
TIP: If you have powdered oxygen bleach, you can create an alternative cleaning solution. Mix 1 gallon of hot water with 4 ounces of powdered oxygen bleach.
Step 3: Apply the cleaning solution using a pump garden sprayer. Be generous and saturate the roof, starting from the top and working down in sections on the roof. Allow the mixture to sit on the roof for at least 15 minutes.
TIP: Wear gloves and eye protection when working with this cleaning solution to lift stains off the roof shingles. Bleach is an irritant that could cause an allergic reaction and damage your eyes.
Step 4: Rinse the roof thoroughly, using the garden hose with a spray nozzle attached. Once again, work from the top to the bottom, to prevent dirty water from contaminating the already cleaned areas of roof shingles.
Step 5: Look for any stains that were not removed. Use more cleaning solution and a soft bristled brush to scrub the stains away. Rinse the area thoroughly once you have removed the dark stains on the roof shingles. You may also have to use a scrub brush to remove particularly stubborn bits of mold and mildew.