Can you Pressure Clean a Shingle Roof

As a homeowner, there are different options available when it comes to picking the suitable material for roofing. Asphalt shingle roofing is quite popular because the material isn’t expensive, can fit many home styles, and is easy to install. But after living at your property for several years, you’ll definitely ask yourself this question: can you pressure clean a shingle roof?

You can, but it’s not recommended unless you’re using very low pressure. As a matter of fact, pressure cleaning a shingle roof can potentially damage it beyond repair if you’re not doing it right.

Keep on reading to learn more about when and how to use a pressure cleaner to clean your shingle roof.

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Can You Pressure Clean a Shingle Roof

Cleaning your roof is part of maintaining it because regular cleaning and removing of debris can actually lengthen the life span of your roofing material. It will also improve the aesthetics of your property.

However, pressure cleaning your shingle roof isn’t the best way to remove the debris and dirt that accumulate on top of the roof. A pressure cleaner can be used to clean various exterior surfaces in your house, but the pressure can damage the protective grit or coating on top of the shingles.

Although your shingle roof won’t break under regular rainfall or even snow, applying water pressure is a different story. The concentrated water beam can crack the shingles, weaken them, and remove the protective grit that protects them in the long run. Applying the water beam in the wrong direction can lift the shingles off their place.

In some cases, you might need to use a pressure cleaner to clean your shingle roof. For example, if you have mold, grown algae, or moss growing on the roof, regular brushing and sweeping won’t be able to remove this buildup. Rainwater and regular cleaning methods won’t remove these plants because the moisture will actually help them thrive.

In this case, using a pressure washer set at low pressure will be suitable because you need some force to remove this buildup. You should also use a special herbicidal chemical to kill these plants as they can cause a lot of roof damage. Other than that, sweeping, lightly brushing, and gently rinsing the roof will be enough to remove dirt, dead leaves, and even ice buildup.

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How to Use A Pressure Cleaner to Clean Your Shingle Roof

The key is to pick the lowest pressure possible to remove the moss or mold without scratching the shingles. Applying too much pressure will damage the shingles or even crack them.

  1. Understand the nature of the buildup you’re trying to remove. For green moss, water will probably do the trick. For black mold, use a special cleaning compound and fill your pressure cleaner with the recommended amount or apply it directly to the plants.
  2. Wear soft non-slip shoes for more safety. Hard shoes can damage your shingle roof.
  3. Place a ladder where you don’t damage the edges of your shingles.
  4. Attach a 40-degree spray wand to the pressure washer.
  5. Start from the highest point on the roof on the side, away from the ladder. 
  6. Turn on the pressure cleaner at the lowest pressure setting. Hold the wand up to widen the beam and reduce the pressure.
  7. Wash downward towards the direction of the shingles so the water pressure doesn’t affect the seal or push the shingles upwards.
  8. Adjust the pressure if it doesn’t seem strong enough to remove the buildup. Make sure that you don’t increase it beyond 1000 or 1200 PSI, or you will see the grit becoming loose. In the case of black moss, apply the chemical compound beforehand to loosen the buildup. You might also need to repeat the cleaning process until all the moss has come off.

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Clay shingles are more tolerant of pressure cleaning than asphalt shingles. They can safely handle up to 1200 or 1300 PSI while you’re using a pressure washer. However, you need to check with your manufacturer to make sure that you’re not damaging your roof while cleaning it.

What Can Excessive Water Pressure Do to My Shingle Roof

Not only will too much pressure break the shingles and weaken their bond, but it will also allow the moisture to saturate the layer that exists beneath. As a result, you can expect your attic to suffer from water damage, which eventually leads to the growth of mold and mildew. The damage can also travel through the walls until you have a serious problem that requires costly repairs.

How Can I Clean My Shingle Roof

There are safer alternative ways that you can use to remove the debris from a shingle roof. Although low pressure can be used in specific cases, there are better cleaning methods that work.

A brush can be used to sweep the roof and will work if you’re struggling with dirt and mud. You can also use a soft brush to remove algae and moss. However, you should be careful not to scrub the shingles too hard to maintain the protective layer.

Use a leaf blower to blow away the dirt and dead leaves. The power of the pressured air will lift the dirt away from the roof, so your roof will end up looking clean.

You can also use a garden hose with a special cleaning detergent if you suffer from moss. A garden hose is different from a pressure cleaner because it doesn’t apply strong pressure.

You can use it alone or with a detergent to keep the shingles clean. If your roof looks dirty and damaged beyond repair, it might be a sign that you need to replace it.

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Conclusion

Cleaning your roof is a good way to maintain it and lengthen its life span. However, pressure cleaning isn’t the most recommended method for cleaning shingle roofs. There are better methods that work, especially if you just want to remove the dirt buildup and dead leaves.

You can use pressure cleaning if you set your pressure cleaner to a low-pressure setting. This will work for you if you have moss, mold, and algae buildup. In this case, you should also use a special cleaning detergent and avoid cleaning the shingles from the bottom up to maintain their bond.

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