Things You'll Need
Oxygen bleach cleaner
Oxalic acid cleaner
Cedar shingles are harvested from both red and white cedar trees and are highly durable. Cedar shingles that are left unstained will eventually become silvery gray in color and may also be prone to tannin stains. Cedar shingles that are continuously exposed to moist, damp conditions are more prone to develop tannin staining, which is also referred to as "extractive bleeding." You can clean tannin stains as well as stains that are caused by dirt and mildew, and make your cedar shingles look like new.
Use a simple mixture of soap and water to remove dirt from cedar shingles. You can remove ordinary dirt stains with a bucket of warm water and a few capfuls of dish soap, applied with a scrub brush. Hose the soap off after washing with a garden hose.
Perform periodic cleanings with a product that contains oxygen bleach. Oxygen bleach products are environmentally safe and can clean the cedar shingles without stripping them of their natural coloring. The oxygen bleach cleaner should be mixed with water according to manufacturers instructions and applied with a scrub brush. You can then rinse it away with a garden hose.
Mix three quarts of water, one quart of chlorine bleach, three ounces of TSP (trisodium phosphate) and one ounce of laundry detergent in a bucket. Scrub mold that has accumulated on the cedar shingles with the solution in the bucket using a scrub brush. Use a garden hose to rinse the cedar shingles after scrubbing.
Remove moss with a solution of four parts water to one part chlorine bleach. Mix the bleach solution in a bucket, apply it with a scrub brush and leave it to dry without rinsing. The bleach will kill the moss, which can be brushed away with a dry scrub brush afterward.
Clean tannin stains with a stain removing compound that contains oxalic acid. Oxalic acid based products can effectively strip away tannin stains and also work to remove mineral deposits such as rust. Spray the cedar shingles down with a garden hose to wet them and apply the oxalic acid product as instructed by the manufacturer. Rinse the product away with a garden hose.
Woodpeckers love cedar shingles. They are notorious for pecking holes, building nests and dirtying cedar shingles. Deter woodpeckers by hanging a wind chime, a hawk mobile or aluminum pie pans around the exterior of your home.
Rinse plants and surrounding foliage with a garden hose after using TSP or bleach. TSP and bleach can kill the plants.
Always wear protective eyewear and gloves when working with chemicals such as TSP and oxalic acid. They are also poisons which should be kept away from animals and children.
Do not use a pressure washer to clean cedar shingles. The pressure from the washer can cause the cedar to split and splinter.