Join the MRA | Member Login
Find a Professional
Sign Up Log In Add New Topic

TOPIC: Corrugated Roof

Cor-ten as roofing OK?

Return to Corrugated Roof

Return to Archive

Return to Forum

Hello, I've seen cor-ten used as residential roofing material in several books (mostly about fancy, modern small houses or cabins). An internet search led me to the U.S. Steel web site, where they advised against using cor-ten as roofing and siding. Does anybody know of a substitute roofing product that resembles the look and feel of cor-ten? Thanks in advance.
Guest User

8/27/2003
No, I do not know of anything similar. There are, however, painted, aggregate-coated, and even powder-coated metal roofs in colors and even textures to resemble rusted metal.
Todd Miller
Isaiah Industries, Inc.

8/27/2003
Depending on the profile you are looking at our granular coatings available on our two product lines can imitate a weathered, pastel brown appearance and give you a 50 year roof. Check us out at www.duraloc.com or www.americanroofingindustries.com
Allan Reid
Dura-Loc Roofing Systems, Inc.

8/28/2003
I think that US Steel is just concerned over liability due to improper installation. I believe the key with cor-ten performance is to allow it to dry completely after it gets wet. That is necessary to form the protective oxidation skin. So if you were going to use a corrigated panel it should be spaced off the roof deck with neoprene washers, and the panels themselves should be spaced from each other the same way. If the panels were to lay directly on each other the area of overlap would never dry completely, and that is the area that would fail. I have to say that I have no actual experience to back this up. It is something I picked up on an architecural web site. I also have to say from actual experience that most "experts" are not. Most people that are supposed to know the answers don't know what they are talking about.
Guest User

9/10/2003
I am sorry for venting but the idea of using a product or material in a way that is not in keeping with the recommendations of the manufacturer or supplier of that product or material has got be the worst advice I have ever heard in my entire life.
Todd Miller
Isaiah Industries, Inc.

9/10/2003
It's quite amazing to me that companies are making roofing material out of CorTen steel when USS, the manufacturer of the raw product, explicitly says it does not recommend it for roofing or siding (see www.ussconstruction.com/metal/corten). Wouldn't those companies be opening themselves to litigation?? On a similar note, how can one determine the aged color of CorTen?
Guest User

11/22/2003
There are no shortage of companies making alcohol and cigarettes as this is what the consumer wants at any price. US Steel was wise in recommending against this as roofing as the manufacturers were possibly misrepresenting the product expectations or at least ignoring the down side. We get numeroud requests each year from consumera and architects who want the aged look. It performs well in dry climates such as deserts or wherever it is kept open and relatively dry so that the natural ozidation process keeps it protected. The problem is people use it in wet, debris and snow conditions where the ozidations is washed off continually staining the eaves, siding and landscape. Not what it was intended to do. As to the colour, it is steel and it will ozidise (rust) and that is a pretty universal colour. It will be redder at the begining and if left as in the desert it will slowly turn yo a dark brown.
Allan Reid
Dura-Loc Roofing Systems, Inc.

11/24/2003
CorTen is the US Steel brand name for ASTM A588 weathering steel. It is my understanding that the concept of weathering steel is that a rust patina will form and this will protect the steel from further corrosion. The problem with using this as roofing is that the patina would be washed off with the rain and thus would not offer the intended protection. Additionally you would have a constant problem with rust stains in the areas where the water runs off the roof. If you have ever seen a bridge constructed of weathering steel, you will frequently see rust stains on the substructure if proper precautions to prevent dripping were not taken.
Guest User

2/2/2004
I am looking for a qualified metal roofing contracotr in Ventura, CA to install Corten roofing on a new residential home. Any recommendations. P.S. Thanks for the input on installation.
Guest User

2/2/2004
I am looking for a qualified metal roofing contracotr in Ventura, CA to install Corten roofing on a new residential home. Any recommendations. P.S. Thanks for the input on installation.
Guest User

2/2/2004
Sorry, I would not put myself in this position. In fact I do not know where you will find a material supplier. Having said that we have an experienced contractor in that area that you could talk to who is listed in the "Find a Contractor" section of this web site.
Allan Reid
Dura-Loc Roofing Systems, Inc.

2/3/2004
Hi I too am very fond of Corten and it's wethered velvet like appearance. I've heard arguments on both sides, contractors say no way and archictects say why not. So I would like to ask about alternatives. I cannot believe other companies have not followed this idea to offer a product which appears to be rusted as weathered steel. I will use this as siding. I'm looking for the color of rust in a satin sheen...if you look at a rusty surface it gives a very velvet sheen. Thanks for any info. Christof
Guest User

2/24/2004
There are newer low gloss painted surfaces available from many manufacturers. Also, some companies may offer powder coat finishes for a softer look or, with formed products, you cxan consider a product with a granular (stone) coating.
Todd Miller
Isaiah Industries, Inc.

2/25/2004
You may want to look at the newest exterior ceramic tile cladding systems from the Tile industry. This year the velvet look of weathered steel or Corten is made by several manufacturers. Look at Tau Ceramica from Spain www.tauceramic.com for one of the best I've seen. The name of the tile is Corten A or Corten B and it comes in panels of 2 foot square or 1 by 2 foot rectangles. The tile is exterior rated and obviously will not cause the staining problems. You'll be amazed when you see it.
Guest User

3/15/2004
Contact Metal Sales. They have a factory in Redlands, CA which produces quite a bit of weathering steel roofing.
Guest User

3/19/2004
Could you please define what you mean by fail? Are you saying that it will rust through? I would be concerned if water was remaining on my metal roof regardless of finish. How is the trapped moisture typically dealt with when using a corrugated profile? Is the corrugated profile approved by any manufacturer for roofing? I see them all the time on agricultural buildings.
Guest User

3/19/2004
I've read everything, and I understand why you might not want to use weathering steel in a wet climate. However, our project is in the desert. We were interested in a standing or flat seam weathering product. Is it possible to site crimp corten? Is this a bad idea due to the lack of air movement? Thanks
Guest User

5/6/2004
Look at www.reclametals.com for a great alternative to COR-TEN. Cold roll looks the same without the harsh environmental concerns as COR-TEN and costs about half the price
Guest User

5/6/2004
I
Allan Reid
Dura-Loc Roofing Systems, Inc.

5/7/2004
This is not a site for non member companies to promote their products not is it a chat room. As to cold rolled steel vsCorten. All bare steel will oxidize to red rust when exposed to moisture. Cor-ten had its chemistry altered so that it would oxidize and allow the oxidation to protect the steel in a non extreme condition such as bridge girders. Cold rolled does not have the same chemistry and will not provide the same performance especially if there are any structural requirements.
Allan Reid
Dura-Loc Roofing Systems, Inc.

5/7/2004