As the roof of your house is daily exposed to harsh environmental conditions like rain, heat, and sunlight, it easily becomes discolored. Discoloration coupled with the growth of mold, mildews, and algae can give an unsightly appearance to the roof, and make your house look worn out. Besides this, organic growth can shorten the life of your roof.
Organic growth, especially algal growth can erode the limestone filler used in roof shingles. Over a period of time, the ceramic granules present on the surface can loosen and then washed off in rainwater. This in turn can reduce the heat-reflecting ability of asphalt shingles, besides shortening their lifespan and compromising their surface integrity.
Algal growth on the roof also paves the way for the growth of lichens and moss, which usually thrive in the gullets and edges of the shingles. They keep the roof damp by holding water and moisture, and cause the edges of the roof to lift up making them vulnerable to wind damage and leaks.
Therefore, regular cleaning is an important part of roof care and maintenance, not only to maintain the aesthetic value of your house, but to increase the longevity of roof shingles.
Cleaning Roof Shingles
Before You Begin
Soak shrubs and all surrounding foliage close to the house with the garden hose. This will help protect your lawn and garden plants from the cleaning solution to be used on the roof shingles. Be sure to take all possible precautions to prevent any accidental fall or slip. It is better to have someone, a friend or a family member nearby, if you need any help.
Use a sturdy ladder to climb onto the roof. To prevent slipping, be sure to wear non-slip shoes. You should also wear safety glasses and gloves during the entire cleaning session.
Things You Will Need
You will need a garden hose, a broom or sponge mop for scrubbing the surface, and a cleaning solution. Recommended Commercial products can be used, or make a homemade cleaning solution by combining 1 cup chlorine bleach and ¼ cup trisodium phosphate with 4.5 liter water. Aso, add a cup of detergent powder to this mixture to increase its degreasing ability.
Spray the Cleaning Solution
Spray the homemade solution on the roof shingles with a pump sprayer. Allow it to stay on the roof for about 15 to 20 minutes. Work from the bottom of the roof, if you are standing on the roof while cleaning it. Stand at the peak of the roof and work in sections beginning with the lowest portion and then gradually working your way up.
This way, you can avoid standing on wet shingles, as wet roof shingles can be quite slippery. It is better to clean the roof on a cloudy day, as this will prevent the cleaning solution from drying quickly.
Scrub with a Soft Broom or Sponge Mop
To clean the dirtier areas of the roof, you can use a broom or a sponge mop. Scrub the areas that are extremely dirty with the sponge mop or the broom while the cleaning solution is still there. However, be sure to scrub the surface gently, as vigorous scrubbing may damage the granular surface of the shingles.
Rinse the Roof
Once you are done with scrubbing the dirtier part of the roof, use a garden hose to rinse the roof shingles. Be sure to rinse the entire roof properly, as chlorine bleach can damage the shingles, if it is allowed to stay on them for a long time.
If you have rain gutters installed on your roof, then push the dirt and debris to the gutters with the help of the garden hose. But be sure to rinse the gutters and the downpipes properly. Otherwise, the cleaning solution may corrode them. At the end of the cleaning session, rinse the garden plants and your lawn properly.
Cleaning Wood Shingles
Wood shingles are preferred by many architects and builders for their natural look and superior performance, especially in areas that experience high winds and hails. However, wood shingles are more susceptible to rotting, splitting, and warping, compared to asphalt shingles.
Like asphalt shingles, wood shingles need regular cleaning, as the accumulated debris can retain moisture and prevent the shedding of water from the roof, paving the way for the growth of wood-rotting fungus on the shingles. Wood shingles can be cleaned with the help of a garden hose and a soft broom.
The use of pressure washing for cleaning roof or wood shingles, is a controversial topic. Excessive and imprudent use of pressure washers can erode the surface of wood shingles. So, get the condition of the roof evaluated by a expert before opting for this. If it is required, use the minimum force possible, and give your roof a topical treatment afterwards.
Care and Maintenance of Roof Shingles
To prevent or minimize the growth of mold, mildews, and algae on the roof, take the necessary steps to improve the circulation of air, and increase the amount of sunlight the roof receives. For that, remove the overhanging tree branches that shade certain areas ensuring tree branches do not touch or rub against the roof, by pruning them at regular intervals.
To prevent algal growth on the roof, place zinc or copper strips near the ridge. Whenever it rains, the rainwater will come in contact with the metal strips, take up ions from them, and produce a chemical reaction that can inhibit the growth of algae and mildews. You can also opt for shingles with algae-resistant granules to avoid this problem altogether.
While using a commercial cleaning product, follow the instructions mentioned on the label of the product. Apart from this, certain chemicals are available, which if applied on the roof once or twice a year, can reduce the growth of mold and mildews. Or, do simple regular cleaning to maintain the look of your roof and increase its durability.