Rustic design has a natural and aged look that has gained popularity in recent years in architectural and interior designs. When it comes to roofing, a rustic appearance can be achieved with the use of steel that arrives unrusted and will rust with exposure to the weather or with painted panels that look rusted.
Standing Seam Metal Roof in A606 Corten Steel
At Western States Metal Roofing, we manufacture rusted metal roofing and siding panels in Corten Steel and bare cold rolled steel that will naturally rust. Even though both products have similar appearances and chemical compositions, they do have differences. In some cases, neither Corten or bare steel may actually be the right fit for your project. In those cases, using painted metal panels that are designed to look like weathering steel would be a better option.
In this article, we discuss the pros and cons of rusted metal roofing and when using painted metal panels may be a better fit to help you decide which to use on your project.
A rusted tin roof is a metal roof where the panels have developed a protective oxide coating on the surface over time which gives the roof a rusted orange color and appearance that is always slightly unique, giving each rusty metal roof its own aesthetic that is one-of-a-kind. While people use the term “tin roof”, the roof is actually made from a different type of metal: steel. Traditional tin roofs are no longer used and have been replaced by aluminum or steel.
The patina can slow down the overall rate of corrosion. In addition to this important function, rusted tin roofing is also popular for its appearance. The antique and natural look of metal roof rust especially blends well with desert, farmland, and mountain areas. However, it's not the right choice for all areas.
Rusted tin roofing is not compatible in climates, including tropical and coastal areas, as the salt spray from the ocean prevents the development of the inner protective oxide layer from forming.
Corten steel has a natural oxidizing finish that not only looks attractive, but also alloys that will decrease the rate of corrosion.
Corten is also referred to as weathering steel or A606-4. It contains a combination of copper, chromium, manganese, and nickel. After the surface rust has developed, the composition of Corten gives it superior corrosion resistance and a greater ability to handle harsh climates compared to bare cold rolled steel.
⅞” Corrugated roof in A606 Corten
Corten steel is a more durable product that can last significantly longer than bare cold rolled steel. Though the cost of Corten is slightly higher, the value is made up in the long term.
The most important consideration when using Corten or bare steel is to avoid using light gauge steel as it will lessen the longevity of the roof. The vast majority of the rustic roofs that we sell are made from 22 gauge steel.
Corten can leave stains known as rust runoff. The chances of this are especially high when the patina is in the early stages of developing and the corrosion rate is at its highest. When the steel gets wet during this time, the rust will “bleed” onto any surrounding area including walkways, driveways, or personal property and leave unappealing rust streaks.
There is no way to avoid the rust stains other than to divert the water to a dirt area. If you have a roof that will drain on to a white concrete it will become stained with red rust streaks.
Corten Has A Higher Cost Compared To Bare Cold Rolled Steel
Corten steel runs anywhere from 30%-50% more per square foot compared to bare cold rolled.
Corten steel does not come with a warranty.
Corten steel will arrive as a new steel that has a dull gray appearance. Once it’s exposed to the weather it will gradually begin to develop a patina. You don’t need to do anything, just let it get wet. It usually takes a few months for the Corten roofing to develop a rusted finish and it will continue to patina further as it ages.
If the Corten steel is being used on an interior application it will have to be pre-weathered prior to installation. This can be a time consuming process that’s doable for small jobs, but is impractical for larger jobs. If you have an inside application, we recommend that you use a painted metal panel that looks rusted.
Bare steel means that it’s an uncoated steel. It has a lesser lifespan versus Corten. However, it’s the most economical option if you are looking for a rusted roof. It should also be ordered in heavier gauges.
Corten and bare steel will both have a similar look after they rust. Bare steel tends to rust a little more orange and Corten has more of an orange brown finish.
Bare cold rolled steel is 30% to 50% less per square foot compared to Corten. If you are looking for the most economical option to achieve a weathered steel roof, you will want to choose bare cold rolled.
Bare cold rolled steel has a significantly shorter lifespan compared to Corten. Every climate and job is different, but it’s about half the lifespan when compared to Corten.
Just like Corten, bare cold rolled steel does not come with a warranty.
Bare steel is prone to rust stains in the same manner as Corten. It’s likely to stain the surrounding areas including sidewalks, driveways and any personal property.
Just like Corten, bare cold rolled steel does not come with a warranty.
Weathering steel comes in different roof panel profiles, including standing seam, R Panel, and Western Rib. However, the most popular rusted metal roofing panel is ⅞” Corrugated.
⅞” Corrugated roof in A606 Corten
Corrugated metal roofing has a wavy, rounded appearance with a bold shadow effect that further enhances the rustic charm of weathering steel. In addition to its appearance, the deep corrugations give the panel extra strength and durability.
Depending on which type of steel and panel profile you choose, the price of a rusted metal roof may vary. The graph below gives you a price range for each type and panel profile.
|
Bare Steel Panel Profile |
Cost |
|
7/8” Corrugated R Panel 7.2 Panel |
$1.50 - $2.00 Per Square Foot |
|
Standing Seam |
$3.00 - $4.50 Per Square Foot |
Standing Seam Metal Roof in A606 Corten Steel
|
Corten Steel Panel Profile |
Cost |
|
7/8” Corrugated R Panel 7.2 Panel |
$2.50 - $3.50 Per Square Foot |
|
Standing Seam |
$3.50 - $4.50 Per Square Foot |
Most Corten or bare steel is 22 gauge. Anything lighter than 22 gauge is not recommended. If your project requires a heavier 20 gauge, it will add an additional 25% more to the cost.
The above price ranges are only estimates. The price of steel varies greatly depending on market conditions. It’s impossible to keep the pricing current for this blog. In order to know exactly how much your project will cost, we highly recommend you request a free quote.
What if you want a rustic looking roof but you want a paint warranty, don’t want to deal with rust runoff, or wait the 3+ months that corten or bare cold rolled steel take to rust? Consider an alternative: painted rusted roofing.
Painted rusted roofing panels, also known as specialty paint prints, are metal panels that have been painted repeatedly to give the finish depth and uniqueness that mimics the appearance of rust.
⅞” Corrugated Metal Roof in Streaked Rust
There is no need to wait for the patina to develop to achieve your desired rust color. Painted metal panels arrive pre-painted in the finish you choose. Instead of waiting months for Corten or bare cold rolled to patina, you’ll have your rustic aesthetic on Day 1 with painted metal.
Since there is no rust, there is also no worry of rust stains with painted metal panels.
Unlike Corten and bare cold rolled steel, painted metal panels come with a paint warranty.
While painted metal panels are designed to achieve a real rusted appearance, they are not going to look as authentic as real rust does up close. However, when these panels are seen at a distance on a roof, it is harder to notice the difference.
Painted metal panels come at a more premium cost. They are roughly one dollar more per square foot compared to Corten
The below price ranges are for specialty panel profiles that are painted to look like real rust.
|
Painted Metal Panel Profile |
Cost |
|
7/8” Corrugated R Panel 7.2 Panel |
$3.50 - $5 Per Square Foot |
|
Standing Seam |
$4.50 - $6 Per Square Foot |
When you’re looking for the right metal roof panel for your rusted roof, there are several different options to choose from. You have to consider your budget, climate, and the look you want your roof to have.
Bare Cold Rolled Steel is best when:
Corten Steel is best when:
Painted metal roofing is best when:
At Western States Metal Roofing, we manufacture all three products. If you are considering a painted metal product, we recommend checking out our color charts to see the painted rusted colors available. You can then see how they will look on your roof with our free roof color visualizer.
To get started on your project today, request a free quote.