Exterior Finishes: Metal Siding / Cor-ten Steel

Metal Siding

Home exterior painted bright colors with metal roof and siding
Brightly painted metal siding and roof

Recently we have seen architects incorporating some beautiful and creative designs using metal for exterior siding applications. So far these have been most successful in contemporary/rustic applications, but I am certain there will be more use of metal on both the exterior and interior in years to come. Metal siding comes in all kinds of materials and styles and each type requires a different coating and maintenance process. I will add discussions on these specifically in the future.

Cor-Ten Steel

Image of rectangular fire pit made of cor-ten steel prior to rusting
Corten steel fire pit beginning to patina

Cor-ten is a type of steel used for exterior applications where a weathered and rusty appearance is desired. This material has rustic, industrial-contemporary good-looks, but is not for every application. 

Generically known as “weathering steel” this product is a family of steel alloys developed specifically to form a stable, rust-like surface appearance to eliminate the need for painting. Cor-ten is US Steel’s trademark name for its weathering steel formula.

The alloys in weathering steel allow rust or surface oxidation to occur naturally over the course of about six months under normal exterior conditions. Use of chemical treatments can help produce the patina appearance in as little as two hours. As the steel surface “rusts” it creates a regenerating corrosion-retarding layer that protects the main structure of the steel.

Cor-ten steel has become wildly popular for outdoor sculptures and architectural facades. The look is so attractive that architects have designed entire buildings using the material and it has a legion of residential fans, including me, around the world. This material appears unfinished and rustic at first glance, and that is what makes it so attractive.

Staining issues

Image of bronze looking steel outdoor sculpture by Archie Held
Stainless steel sculpture with patina by Archie Held

Attractive as it is, weathering steel is not perfect for all applications. Its use should be thought through before construction. Cor-ten can be challenging and even damaging to surrounding areas if used improperly. Rust bleeding or runoff from the steel surface can stain surrounding paint, stucco, stone or concrete. Avoid using this material where staining can be a problem. Also, this material is sensitive to humid climates and it is possible that in these areas the protective patina may not form properly, thus allowing the steel to continue to corrode.

Attempts to paint weathering steel have been unsuccessful because paint retards the protective patina from forming properly. When this happens, deep corrosion can occur at localized areas of oxidation like under small paint cracks or chips.  

World class artist Archie Held likes the look so much that he developed his own formula to patina stainless steel in order to duplicate the appearance for his sculptural water features. As shown by example, if designed well and properly executed, Cor-ten steel can add an exciting and unique appearance to your projects!

More on Metal Siding & Cor-ten Steel...


Home Zones

All
Plumbing
Climate
Electrical
Structure
Windows/Doors
Interior
Appliances
Utilities
Landscape
Emergency
Plumbing
Plumbing
Climate
Climate
Electrical
Electrical
Structure
Structure
Windows/Doors
Windows/Doors
Interior Finishes
Interior Finishes
Appliances
Appliances
Utilities
Utilities
Landscape
Landscape
Emergency
Emergency
Plumbing Systems
Plumbing Systems
Main Water Service
Main Water Service
Fittings & Fixtures
Fittings & Fixtures
Water Heaters
Water Heaters
Waste / Septic Systems
Waste / Septic Systems
Fire Extinguishers
Fire Extinguishers
Climate Control
Climate Control
Thermostats
Thermostats
Heat Sources
Heat Sources
Air Quality
Air Quality
Air Conditioners
Air Conditioners
Exhaust/Ceiling Fans
Exhaust/Ceiling Fans
Mold/Mildew
Mold/Mildew
Condensation
Condensation
High Efficiency Furnaces
High Efficiency Furnaces
Electrical
Electrical
Switches
Switches
Outlets
Outlets
Lighting
Lighting
Distribution Panels / Circuit Breakers
Distribution Panels / Circuit Breakers
Smoke / CO Detectors
Smoke / CO Detectors
Electric Water Heaters
Electric Water Heaters
Structure
Structure
Exterior Finishes
Exterior Finishes
Roof System
Roof System
Insulation
Insulation
Fastners
Fastners
Foundation
Foundation
Basement / Crawlspace
Basement / Crawlspace
Attics
Attics
Termites
Termites
Windows
Windows
Doors
Doors
Locks/Hardware
Locks/Hardware
Weatherstripping
Weatherstripping
Interior Finishes
Interior Finishes
Drywall
Drywall
Trim Work
Trim Work
Flooring
Flooring
Mirrors / Shower Door / Glass
Mirrors / Shower Door / Glass
Cabinets / Countertops
Cabinets / Countertops
Paint / Coatings
Paint / Coatings
Hardware
Hardware
Stairs/Railings
Stairs/Railings
Appliances
Appliances
Ovens
Ovens
Cooktops
Cooktops
Exhaust Hoods
Exhaust Hoods
Disposals
Disposals
Dishwashers
Dishwashers
Compactors
Compactors
Refrigerators / Freezers
Refrigerators / Freezers
Ranges
Ranges
Washer / Dryers
Washer / Dryers
Central Vacuum
Central Vacuum
Microwave Oven
Microwave Oven
Utilities
Utilities
Underground Systems
Underground Systems
Electricity / Communication
Electricity / Communication
Water-Municipal / Wells
Water-Municipal / Wells
Natural Gas / Propane
Natural Gas / Propane
Sewer / Septic
Sewer / Septic
Garden
Garden
Hardscape
Hardscape
Lighting
Lighting
Driveways
Driveways
Outdoor Furniture
Outdoor Furniture
Outbuildings
Outbuildings
Living with Fire
Living with Fire
Family Emergency Strategy
Family Emergency Strategy
Earthquake Preparation
Earthquake Preparation
Surviving Snow
Surviving Snow

Help me to help you

Thank you for taking time to use this free website. I hope you find the junk-free information here fun and useful? Please send me your comments and feedback.

Writing and maintaining the information in this manual is a lot of hard work. By sharing these pages with your friends, you help me to continue the effort.  You can easily share these pages to all your favorite social media sites via the shortcut buttons on the sidebar. You can also simply email the page link to your friends. Please share often.

The very best way to help me happens when you use the embedded links to buy things. Using a link is easy and free, yet it provides a great source of support for this site. The vendors I've chosen to link to have proven to be trustworthy and are the very best resources available. That is why I recommend them personally.

HomePreservationManual.com is the place to visit if you want information on

  • maintaining your home
  • how to improve air quality
  • ways to improve the real value of your home
  • what are the best housekeeping services
  • the problems with handymen services
  • how to plan and execute home renovation and home improvement projects
  • tips for spring cleaning; tidying up a messy house
  • and generally how to be a better homeowner.

Make sure you download your monthly maintenance checklist for this month.

Linking to this site

Do you want to link to anything on this site? Please do! Go right ahead. I appreciate it and am honored to be considered as a resource on your website. Always feel free to link to anything you find helpful. Of course, please never copy anything (everything is copyrighted and registered), but link away and thanks!

Thank you!

Copyright and permission to use information.

If you have questions or just want to say hi, please send me a note. If you are looking for help performing the work described and you are in the San Francisco area, go to HPS Palo Alto Inc.and request a free evaluation.

As a reminder, it is unlawful to make copies including cut and paste or especially in the form of making printouts for reuse. If you wish to make a print for personal use, I will happily grant you one-time permission if you will kindly send me a request in writing.

Thanks again!