Interesting Industrial Materials: Cor-Ten Steel
Use the Rust-Rich Metal for a Variety of Exterior Applications
Cor-Ten steel is the trademarked but common name for steel in which various alloys are added to create a layer of rust on its surface. Also called weathering steel, this oxidized surface eliminates the need for paint or some other weatherproofing treatment. It also gives steel a unique appearance embraced by artists (Richard Serra, in particular) and architects alike. The material first found application in capital-A architecture in the 1960s, with sizable buildings like the Ford Foundation in New York City, the Time-Life Building in Chicago and, naturally, the U.S. Steel Tower in Pittsburgh (U.S. Steel Corporation holds the Cor-Ten trademark).
In contemporary architecture the scale of application isn't so grand, finding its way in the occasional cultural or academic building and into residential structures both urban and rural. Its heavy and industrial appearance means that the material will be found in suburban contexts, if at all, in a pared down manner — more often as a landscape feature than a house's cladding. Many times patinated copper can be mistaken for Cor-Ten steel, and vice-versa, but in general copper retains some of its green, while Cor-Ten consists of shades of brown and orange. Below are a variety of Cor-Ten steel applications that illustrate the material's singular appearance.
In contemporary architecture the scale of application isn't so grand, finding its way in the occasional cultural or academic building and into residential structures both urban and rural. Its heavy and industrial appearance means that the material will be found in suburban contexts, if at all, in a pared down manner — more often as a landscape feature than a house's cladding. Many times patinated copper can be mistaken for Cor-Ten steel, and vice-versa, but in general copper retains some of its green, while Cor-Ten consists of shades of brown and orange. Below are a variety of Cor-Ten steel applications that illustrate the material's singular appearance.
This house, according to the architects, "presents raw, honest materials appropriate to the grittiness of the Venice [California] environment." The corner lot is defined by a wall composed of various materials, each one reiterated in the house's design. Walls of Cor-Ten steel are visible behind this wall and retractable awnings hang on a steel frame. A closer look...
... Reveals that the Cor-Ten volume sits next to the swimming pool. The concrete block and wood siding can be found at left; the former extends inside and the latter covers the upper floor. The Cor-Ten gives a splash of color that is highlighted by the gray palette of the other materials. Only the bright orange of the awnings competes with the rust in terms of color.
It should be pointed out here that Cor-Ten tends to stain adjacent materials, especially concrete. I'd be curious if this homeowner has any issues with the rusty steel on the concrete slab next to the pool.
It should be pointed out here that Cor-Ten tends to stain adjacent materials, especially concrete. I'd be curious if this homeowner has any issues with the rusty steel on the concrete slab next to the pool.
This house in the Ocean Beach section of San Francisco is actually an addition to a Mid-Century Modern home (visible on the photo's left edge) designed by Ernest Born. Aidlin Darling's Cor-Ten box is smaller in footprint than the wood-clad original, so their choice of material allows the new to have a visual weight that works with the old. The gap between the two cubes...
... Is bridged by a walkway covered in translucent glass. Here we are looking towards the front of the house; the Pacific Ocean lies beyond the wood-slat fencing. This view illustrates how the Cor-Ten steel works well opposite the wood shingles. There is an obvious decision on the part of the designers to create something contemporary that relates to the existing building; copying the wood shingles would have diminished the distinction between old and new.
This townhouse designed by Jim Jennings confronts its industrial area with a Cor-Ten steel facade. One half is highlighted by translucent glass, which extends behind the perforated steel panels to hint at the light-filled house within. The initial design coincided with the Dot-com Bubble and it is even located in the city's South of Market area, home to many of the tech start-ups at the time. In the years since, the "ceaseless graffiti" of the neighborhood led the architect to replace the Cor-Ten steel with stainless steel. Needless to say, it is hard to remove spray paint from a layer of rust.
Cor-Ten steel does not have to be applied to thick panels, like in Richard Serra's artwork. In the case of this barn that accompanies a larger main house in Santa Cruz County, California, the rust is found on corrugated steel sheets that comprise the walls and roof. The barn is a renovated warehouse and the architect's treatment of it gives it a very monolithic appearance. (A close look at the concrete footing behind the plants in the lower left illustrates the staining that comes from using weathered steel.)
Another view of the barn wrapped in rusty corrugated steel hints at what is found on the main building: The garage door is made of the same reclaimed wood that covers the walls of the main house. It should also be noted that the corrugated metal seen here also covers the roof of the main house. The old wood and rust combined to make the house appear rustic in its natural setting.
The previous projects illustrate extreme examples of using Cor-Ten steel. But most people will probably opt to use it more selectively, not covering facades with rust. This house by Laidlaw Schultz Architects, for example, limits the material to the fence and front gate. That they use the same material for the gate seems great to me; the weight of the panel and the force needed to move it (I'm guessing some very good hinges make it possible to use a piece of steel as a gate) strongly mark the transition from the public street to the private domain of the house and its yard.
A closeup of the steel fence and the stainless steel numbers projected in front of it is a great illustration of the color variation found in Cor-Ten. From afar the material has a monolithic appearance, but in reality the various browns, oranges and even blacks reveal the natural processes at work on the steel.
In an even smaller application, Cor-Ten steel is found on a planter and framing a portal in the front of this townhouse. Here the rust is clearly used to complement the color of the door, both on the opposite spectrum of the blue steps and the variegated blue tiles of the facade.
In this fountain, Cor-Ten steel is again found adjacent to variegated blue tiles. Clearly there is something about the orange in the rust working well against blue, but here the minimalism of the fountain — just a narrow horizontal slot in the wall — is extended to the basin. Using another material (for example, the wood of the decking) would add too much detail, something avoided with the seamless steel construction.
This backyard landscaping uses Cor-Ten steel walls for edging, alternating with concrete and wood benches in a zigzag pattern. The rusty steel is used in a planar manner, jutting from the ground in sheets. Needless to say, this isn't a yard for kids to run around in!
This last example utilizing Cor-Ten steel clearly illustrates what is industrial about the material: its durability. Not many materials in a flat panel could handle this sort of application. And with Cor-Ten, the mark that comes from fire just adds to the character of the steel.
More materials to use at home:
A Periodic Table of Design Elements
Today's Concrete: Warm and Wonderful
Pure Modern: Pick Plywood
More materials to use at home:
A Periodic Table of Design Elements
Today's Concrete: Warm and Wonderful
Pure Modern: Pick Plywood