Three Ways to Clean Unsightly Roof Stains

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This information will help clear up any confusion you may have when it comes to cleaning methods for your roof.

Shingles contain organic material that feeds roof-staining organisms, such as algae, moss, and lichens. These organisms eat your roof over time and left untreated, and they will cause significant damage to your roof.

The bleach-free and eco-friendly method

This method is good for the environment. Companies that use this method use products that do not contain toxic chemicals like bleach (chlorine) and phosphates. These chemicals are known for polluting waterways and kill vegetation. This eco-friendly method also uses low-pressure rinsing instead of high-pressure rinsing or brushes that can lead to damage.

Positives: This method gives you an instant and thoroughly clean. Before the crew leaves your property, the algae, moss, and lichens are gone. Eco-friendly shampoos and specialized equipment is used in this method, providing a safe and gentle clean for your roof and the environment. This method ensures the landscape surrounding the roof is safe while also preserving the integrity of the shingles.

Negatives: Because of the higher cost of eco-friendly products, this method costs more than methods that use cheaper cleaning solutions like chlorine bleach.

Helpful hints: Be sure to hire a contractor who will guarantee that the algae, moss, and lichens stains will be removed before they leave your property. It is also a good idea to find a contractor who offers a yearly prevention program for your roof.

Bleach method

Contractors who offer this method use a solution that has a mix of chlorine bleach (sodium hypochlorite) and other harsh chemicals, such as TSP (trisodium phosphate).

This mixture is sprayed on the roof and left to dry, and then the process is repeated until all the algae, moss, and lichens are gone. The stains don’t always clear on the day of application, and it can take weeks to months to eventually wash off in the rain.

Positives: The chemicals used in bleach cleaning methods are inexpensive, so this method costs less than its eco-friendly alternatives. The contractors don’t have to get on the roof to inspect their work.

Negatives: Results are not instant, particularly when your roof is heavily infested with moss and lichen colonies, and there is often a strong chemical odor post-cleaning. The smell and residual chemicals pose risks to people and pets. Moreover, these chemicals can significantly damage your surrounding vegetation—plants, trees, shrubs, and flowers. To mitigate this, consulting with arborists in Victoria can be crucial for developing strategies to protect your garden and trees from potential chemical damage. Additionally, these chemicals are harmful to the water supply, as they may seep into the ground and eventually contaminate local waterways.

Helpful hints: Contractors don’t often disclose that they are using harsh chemicals. One way to tell whether they are using bleach or other harsh substances is in the way they prep for the job. If they wet the surrounding vegetation surrounding your property before, during, and after the job, they are likely trying to use runoff techniques to protect your plant from the chemicals. They may also cover the vegetation with plastic.

Pressure washing method

Another method contractors use for stain removal is high-powered pressure washing.

Positives: There are no benefits to using this method.

Negatives: This method will not only damage your shingles, but it is not a very effective way to remove algae, moss, and lichens stains. This method does not completely rid the roof of root systems, so the stains quickly return.

Helpful hints: One way to tell whether the contractor is using too high pressure, ask them to hold their hand in the stream of water. If they can’t, you know the water pressure is too high and will damage your roof.

As a homeowner, it is good to know the various types of shingle cleaning methods so you can make an informed decision about your roof-cleaning contractor. You will be prepared to ask questions and ensure your roof is adequately treated. You want to have a stain-free roof so that not only will the home value improves but also it will last longer.

Cleaning your roof properly allows it to function the way it was intended to—naturally and efficiently. Give your roof the best chance to last for years to come by keeping it clean.