Use a 12-volt pump system with pressure of about 60 PSI.
You can use a small brush to scrub shingles individually or a large brush on a pole to clean many at one time.
Use proper safety equipment, including goggles and gloves. Do not use liquid detergent or a detergent that contains ammonia. This could cause a dangerous chemical reaction with the bleach. [1] X Research source
Citric cleaning solutions should be specially formulated for cedar shingles and may include algaecide, mildewcide, and fungicide. Commercially available citric solutions may also contain a water-based oil that will help rehydrate your shingles.
Allow the bleach or citric mixture to sit for about 15 minutes. [2] X Research source
The water from your garden hose should have about a 40 PSI. Rinse your roof from the top down, so you can clear off all residual debris.
You may be able to cut smaller limbs or branches by yourself. If you have large limbs that overhang your roof, you may need to call in a tree cutting service. [3] X Research source
If you have a long broom or pole, you may be able to remove a lot of debris from the ground or from a ladder. [4] X Research source
If you’re not comfortable replacing a shingle yourself, you should contact a licensed roofer or contractor to do it for you.
Be very careful using oxalic acid, as it is a toxic substance. Oxalic acid won’t keep shingles bright. If you don’t remove the source of the stain (usually iron from certain nails), you’ll have to apply it again. [5] X Research source
Cedar shingles in wet and overcast climates should be cleaned yearly. Cedar shingles in sunny and dry climates may only need to be cleaned every 2 to 3 years. [6] X Research source
