Metal roof is the best option for home roofing. It is safer than other roofs because it tends to last longer and be more robust. However, it has disadvantages.

One of the most common issues of metal roofs is rust.

Metal roofs tend to be rusted because of environmental elements. When the metal roof rusts, it won`t look beautiful. If your roof is in a similar situation, you wonder what can be done to improve your roof and look new again.

You can change the roof to a new one, but it may be expensive. Luckily there is another way. It could take more work and effort, but you can do it.

Let`s look at the article and find ways to do it.                   

Can you paint a rusted metal roof?

Rust makes your roof look dirty and unappealing. Changing your rusted metal roof to a new one is expensive. The first thing you think of is painting the roof to look better.

But, you may have a question ‘Can I paint a rusted metal roof?’

The obvious answer is you can. But it will take more time as you should follow a few steps. Before just painting the roof, you should do something about the rust. 

Why does rust develop 

 We know rust as a reddish-brown flaky coat that develops on metal. But rust is the term generally used for the corrosion and oxidation of iron—rust forms when acidic substances contact metals, such as iron and steel.

Rust usually occurs when certain metals are exposed to oxygen and water for a long time. As iron reacts easily with oxygen, rust is widespread. Water itself will produce the quickest reaction. 

What damages can rust cause

As rust can occur on many metals, you should know the impacts rust can have on your metal roof. If you notice any damage on the roof, it results from rust.

Suppose you notice the rust but do not let the rust will eventually widen. Rust can start small but can quickly spread. It can also cause cracks, holes, and leaks on your roof.

Rust is non-toxic and has no biological hazards. However, rust can severely affect the metals and makes them weaker.  After some years of damage, this will cause more damage. In the worst scenario, it may require being replaced.

How can you avoid rust developing

Although rust is one of the common problems among metal roof owners, there are ways to prevent rust from developing.

  • Take care of any rust – check your roof to see whether it has any rust, spot, or crack. If you notice any rust, try to avoid the rust widening to the entire roof. Wash your roof or clean your roof with a wire brush.
  • Use a primer – to prevent your roof from rusting, use a rust protection primer before painting.
  • Add some coating – to stop rust and corrosion; you can apply some extra coats. These protection layers are the most effective methods to keep the roof from moisture and air. And, of course, these layers prevent the rust from rusting.
  • Galvanization – is the keyway. Galvanizing the roof has more advantages. It prevents the roof from being rusted. Moreover, it makes the roof more durable and robust. Galvanizing the rusted area prevents the rust from spreading to an entire roof.

Preparation to Paint rusty metal roof

A metal roof is similar to any other metal surface in painting. You must follow some basic steps before prep, prime, and painting.

Before beginning any steps, ensure you have chosen the right day for the right weather to refresh your metal roof.

And there is a table of things you need to begin and make your old rusted metal roof become a new roof.

Wire brush                                                   

The most crucial tool is the wire brush. You will need it to remove any rust and

unwanted paint or any dust.

Trisodium phosphate

Trisodium Phosphate is commonly called TSP. It is a packaged cleaning product. TSP is an effective and heavy-duty cleaner.

It is inexpensive and an excellent cleaner. And you can find it easily. But obey the safety rules while using this product.

Pressure washer

you can use this mechanical machine to spray the chemicals or to clean your old rusted metal roof.   


before painting the roof, applying primer is one of the best ways to make it last longer. You can use a rust-protective primer to avoid your roof rusting.


if you have used rust protective primer, now you can use standard paint. In other cases, you must use some special paint to avoid rust. Water-based metal roof paint is the best option for this case

How to clean your metal roof

It will take some physical effort to clean your metal roof from rust. There are two main strategies you might use to manage this.

The first way is to use chemicals to neutralize and weaken the rust to remove it using a scrub brush.

You’ll need the assistance of a pressure washer for the second option.

Before attempting either procedure, use a dry scrub brush to remove the larger flakes of rust from your roof.

Here are the methods to remove Rust From a Metal Roof

The first method is: Remove the rust with Trisodium Phosphate. 

No product can release the rust and help remove stains while also preventing the rust from spreading. It’s a common chemical that most local home improvement stores carry.


You should use Trisodium phosphate carefully. It’s a harsh chemical that performs an excellent job, but you don’t want it on your skin, clothes, eyes, etc. Wear rubber gloves and clothing that you don’t mind trashing if something goes wrong.

Before using the trisodium phosphate, make sure it’s diluted. It is available in powder form and must be blended with water at a ratio of one cup of trisodium phosphate to one-gallon water. Once mixed, use a sprayer to apply it to a rusted area. Give it 15 minutes to penetrate the rust and start working. Scrub all the rust. And then, remove as much of the staining as possible using a hard-bristled scrub brush.

The second method: Using a Pressure Washer to remove the rust

You may not want to expose yourself to the harsh trisodium phosphate. In this case, you can use a mechanical method instead of washing by hand. 

You will need to use a pressure washer to do this. And it needs to reach at least 2500 PSI to remove the rust from your metal roof. 

Simply turn up the spray pressure and begin spraying. Make sure to spray the entire roof, knocking loose any rust flakes and removing as much oxidation coloration as possible.

Extra tip: You can also combine these two methods to remove the rust from your metal roof. Using this method gives you more chances to remove the rust.

Apply trisodium phosphate on your metal roof. Leave it 15 minutes and then set the pressure washer to 2500 PSI.

Now, spray it on the surface. With this, you don’t have to scrub it by yourself. The pressure washer and the chemical will do it themselves.

Wipe the roof with Vinegar.

Corrugated metal roofs are made with a galvanized coating to prevent corrosion. To stick the paint, you should neutralize the zinc with an acid. And before applying primer and painting, you have to coat the roof with vinegar. 

You can use white vinegar. It is entirely natural, easy to find, cheap, and harmless. First, apply some vinegar to a piece of cloth. Then wipe down the roof with that cloth. Don’t scrub hard! slightly apply the vinegar to all parts of the roof. Don’t miss any areas!

How to paint a rusted metal roof

Painting a metal roof is similar to painting any other metal surface. As mentioned before, preparation, primer, and painting are the three simple steps you should follow.

Apply the primer

After completing the preparation part, it is time to apply a primer. The vinegar from the previous preparation step should evaporate pretty quickly, do not wait a lot before applying primer.

Using suitable materials helps you to ensure that your paint adheres appropriately and the rust never returns to your metal roof.

All of these start with choosing the right primer. As you are painting an old, rusted metal roof, you should choose a primer to stop the rust from developing and widening. Fortunately, there are these kinds of primers.

 And to use them, you have to follow the instruction on the can of primer. You can also be aware of the specific instruments to apply the primer from the manufacturer.

You can apply it with a roller or a paint sprayer. Technically, you can use a paintbrush or spray can, but this may take your time.

Apply the primer to the entire roof, and don’t miss any spots or even a small spot.

After applying primer, wait for the roof to cure before applying the paint fully. You can read about drying time in the instructions. Most primers will be ready for painting within 24-48 hours.

Extra tip: Keep in mind when applying the primer, don’t walk on the roof. The roof needs to dry before you can walk there. So use a ladder in front. And then let it dry for 1 or 2 days before painting.

Apply the paint

You have coated your rusted metal roof with primer. And finally, it is time to paint.

As you apply rust-killing primer, you can now use standard exterior paint. You can add another protection layer and rust-preventative paint with a protective finish. This will help your roof ensure.

Before applying paint, you have to be sure that the primer is completely dried. If you paint before drying, it will ruin all your effort. It requires you to remove all of it and restart the painting project.

When you are sure the primer is dry, start painting. You can apply the paint the way you applied the primer. The most efficient method are using a roller or a paint sprayer.

And be sure to cover the painting on the whole roof.

Tip: It is recommended to check the weather before painting. If it rains or a storm comes, they ruin all your hard work. To avoid this kind of problem, we recommend you check the weather forecast before beginning your project work.

Final coat

You have already covered your roof with primer and protective enamel. So it is well-protected. Possibly, your roof doesn’t require any additional protection coat. But you should look at the finish of your roof. Look carefully for any darker or lighter spots. You might apply the paint more or less heavily. If you find these areas a lot, you can apply an additional paint coat. When it dries, your old rusted metal roof will be entirely changed into a new roof.  It may even look better than it did the first time.

Final thoughts

Painting a rusted metal roof likely seemed like boring work. But a few hours and your hard work will pay.

Your old rusted metal roof changes to a new one. A rusted metal roof affects the outlook of your entire house.

And now you know how to paint the rusted metal roofs. You can give your old rusted metal roof a new perfect look by following the steps given above.


1.  Do I need to remove all of the rust before painting?

The obvious answer is ‘yes’. If you don’t remove the rust before painting, it will continue spreading to the entire roof. And it weakens the surface of your roof. Remove the rust as much as possible before painting.

2.  Should I treat the rust before painting?

You should. It is recommended. If you treat the rust, you can protect your roof from rusting. Painting without treating the rust causes other damage to your newly painted roof. So you have to treat the rust before painting.

3.  How long does the paint last on the metal roof?

     The paint lasts approximately 10 – 15 years on the metal roof. But the longevity of paint depends on your maintenance practices, the weather conditions in your area, the type of paint, and some other reasons.

4.  What is the best paint for a rusted metal roof?

Water-based metal roof paint is the best paint for rusted metal roofs. This paint contains rust inhibitors. So you can use this paint for rusted metal roofs. If you want to apply two coats, allow the firs