How to Clean a Metal Roof From the Ground

How to Clean a Metal Roof From the Ground

A metal roof looks great. Its slick surface helps to prevent the buildup of dirt, leaves and other debris. But the slipperiness makes getting on your roof to clean it a hazardous task. Although metal roofs require little maintenance, they do need a deep cleaning every few years. If you plan to wash it yourself, find out how to clean a metal roof from the ground so that you can stay safe.

Why Should You Clean a Metal Roof?

One of the primary benefits of a metal roof is its durability. It stands up well to heat and precipitation and repels water and grime. Mold and mildew are less likely to accumulate on metal roofs than other materials.

However, a metal roof is still exposed to the elements 24 hours a day. Over time, pollutants and organic particles can build up on the surface. These can cause the finish to deteriorate, causing structural and aesthetic concerns. Plus, debris and stains can make your roof look unattractive and cause corrosion.

Cleaning the roof removes damaging buildup. It also eliminates and prevents stains, helping your roof look its best and last as long as possible.

How to Clean a Metal Roof From the Ground

Walking on a metal roof can be dangerous for the person and the roof. You can clean the roof from below, but it’s difficult to clean it thoroughly from the ground.

For the most comprehensive cleaning, you’ll need an OSHA-approved safety ladder or scaffolding. This job is best completed by more than one person; you should never climb up a ladder, scaffolding or roof by yourself.

It’s best to clean the roof on a dry, overcast day. If the sun is too strong, it could cause the water to evaporate too quickly.

1. Remove Visible Debris

Use a broom or roof brush to remove loose debris, such as branches, twigs, pine needles and leaves from the surfaces that you can reach. Take this time to clear the gutters. When you wash your roof, you’ll want the drainage to be optimal so that you don’t leave cleaning residue on the surface.

Don’t use a blower for this task. Unless you’re directing the airflow down the slope of the roof, you risk blowing debris into vents and attic spaces.

2. Hose Down the Surface

A hose will help you access hard-to-reach spots on the roof. Use a nozzle attachment to control and extend the spray.

Using a strong stream, wash the remaining dust and grime from the metal. Perform this step slowly and meticulously, letting the power of the stream do its work.

Although it’s possible to use a power washer on a metal roof, it’s not recommended. The stream from a power washer is extremely forceful and can damage the surface. It can dent the metal or cause deterioration.

3. Tackle Stubborn Stains

Mold, mildew, algae and moss can create stains on your metal roof. If you can reach the stains by hand, you can wipe them off with a soft cloth. Never use an abrasive cleaning tool on a metal roof.

If the stains are especially stubborn or you don’t want to climb a ladder, you can use a cleaning solution that’s designed for metal roofs. Check with the manufacturer of your roof to determine which products are safe to use.

Many roof cleaning agents come in a container that attaches directly to the garden hose. The nozzle should have several settings to allow the spray to reach the roof from the ground. Follow the directions on the product label to wash and rinse your roof. Use precautions, such as wearing protective clothing and safety glasses, when using chemical products.

4. Remove Oxidation

Some metal roofs develop rust stains over time. These require more elbow grease to remove. If you can reach the stained areas from a ladder or platform, you can scrub them with an abrasive cleaner, such as Soft Scrub. Use a non-abrasive cloth or pad and gentle pressure.

However, it’s a good idea to have a professional inspect your roof if you notice corrosion. Rust could be a sign of deterioration, which needs to be further addressed.

Rust isn’t the only sign of oxidation. Painted metal roofs can develop a white, chalky finish over time. This is caused by exposure to sun, wind and weather and lack of maintenance. The paint layer begins to come off and creates a white, powdery surface.

Removing the chalky layer is an intricate process that should be left for the professionals. It’s difficult to do from the ground and requires a special solution that restores the roof to its original splendor. In fact, the chalky texture is a sign that your metal roof needs a deep cleaning.

Pros and Cons of Cleaning a Metal Roof From the Ground

There are many benefits to cleaning a metal roof from the ground. However, it’s not always the best option. In certain situations, you may need to hire a professional to clean the roof thoroughly from above.


  • You’ll avoid damaging the surface of the roof.
  • You’ll reduce your risk of falling.
  • It requires minimal equipment.
  • It can be done as frequently as necessary.


  • You’ll likely have to use a ladder for part of the job, requiring you to take the appropriate safety precautions.
  • You won’t be able to inspect the roof and vents for damage.
  • You may not be able to remove all of the stains.
  • You need to be careful when using caustic chemicals on a metal roof.
  • Placing a ladder against the roof without a buffer can damage the metal.

Should You Clean Your Metal Roof Yourself?

If you have a garden hose and a low roof, you can clean your metal roof from the ground a few times a year. You should also remove debris from your metal roof regularly. Do a deep cleaning every two or three years.

Test chemical cleaners on a small roof area to ensure that they don’t interact negatively with the material. Checking with the roofing manufacturer or a professional roofing company will prevent you from using a solution that harms your roof.

If you can’t see much of the roof from the ground or don’t have a garden hose, you may want to hire a professional to clean it. A licensed, insured roofer can access the entire roof safely and knows how to remove stains and debris without harming the material.

At Presidio Roofing, we perform inspections, roof repair and roof maintenance. Let us take a look at your roof and recommend the best cleaning and maintenance options to extend its life and prevent leaks.

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