How to Install Corten Steel Siding on an Existing House
Sep 07, 2026
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What Is Corten Steel Siding?
Corten steel siding is made from weathering steel, a special alloy steel containing copper, chromium, nickel, and phosphorus. When exposed to natural weather conditions, it forms a protective oxide layer that prevents further corrosion.
Corten Steel Siding is an architectural and decorative material used for building facades, windows, flooring, and roofing. It may also serve as fencing, screening, protective panels, and drainage channels.
This material finds extensive application in both indoor and outdoor settings, including:
- Gardens and parks
- Residential and commercial buildings
- Art galleries and museums
- World Expo venues
- Cultural structures such as memorial halls
Retrofitting Over an Existing Wall: What's Different
Unlike a new-build rainscreen system installed directly onto a structural frame, retrofitting Corten siding onto an existing house usually means building out from your current wall surface. This changes a few things:
1. Do you need to remove the old siding first?
Not always. If your existing siding (vinyl, wood, or fiber cement) is flat, sound, and not rotting, Corten panels can often be installed over furring strips fixed through the old siding into the studs, creating an air gap behind the new panels. If the existing siding is damaged, warped, or has moisture problems underneath, it should be removed and the wall inspected before proceeding.
2. House wrap matters more on a retrofit
New construction typically has a fresh weather-resistant barrier already in place. On a retrofit, check whether your existing wall has effective house wrap; if it's decades old or damaged, this is the right moment to add or replace it before covering the wall with new furring strips and panels.
3. Furring strip spacing
Vertical or horizontal furring strips (pressure-treated wood or galvanized steel hat channel) are fixed through the existing wall into the studs, typically spaced 400–600mm apart depending on panel size and local wind load requirements, creating the ventilated cavity Corten siding needs to perform well long-term.
Step-by-Step: Retrofit and Installation of Corten Steel Siding
1. Inspect the Existing Wall
Before installing Corten steel siding, inspect the existing wall for rot, moisture damage, loose materials, or significant unevenness. Pay particular attention to areas around windows, doors, roof lines, and wall penetrations.
If the existing wall or siding is damaged or has an ongoing moisture problem, repair the underlying issue before covering it with new siding.
2. Confirm or Install House Wrap
A weather-resistant barrier helps protect the wall assembly from water that may pass behind the siding. On an existing house, check the condition of the current house wrap or weather-resistant barrier before installing the new cladding.
If it is damaged, missing, or no longer effective, repair or replace it before installing the furring strips.
3. Fix Furring Strips
Install vertical or horizontal furring strips through the existing siding and into the wall studs or other suitable structural support.
As a general installation reference, furring strips may be spaced approximately 400–600 mm apart, depending on the Corten panel size, fixing method, substrate, and local wind-load requirements.
The furring system should create a continuous ventilated cavity behind the Corten panels. A typical cavity may be around 20–40 mm, but the final dimension should be determined by the project design and drainage requirements.
4. Fasten the Corten Panels
Install the Corten steel siding panels onto the prepared furring system using fasteners compatible with the panel and installation environment.
For exposed fastening systems, corrosion-resistant stainless steel fasteners or other project-approved compatible fasteners can be used. The fixing pattern should be determined according to panel dimensions, wind loads, support spacing, and the manufacturer's installation recommendations.
Do not treat Corten siding like lightweight vinyl siding. The supporting structure and fixing system need to account for the greater weight of steel panels.
5. Seal Joints and Penetrations
Pay particular attention to areas around windows, doors, vents, corners, and other wall penetrations.
Install appropriate flashing, drip edges, and drainage details where required. Sealant should be selected for exterior exposure and used according to the wall assembly and project detailing rather than simply sealing every panel joint.
Before completing the installation, check that the panels are aligned, the ventilation cavity remains open, fasteners are secure, and water has a clear drainage path.
How Does This Compare to Installing Vinyl or Wood Siding?
Homeowners comparing Corten to more familiar siding materials should know a few key differences:
- Weight: Corten steel siding is significantly heavier than vinyl and generally heavier than wood siding of comparable size, so the furring strip and fastening system must be sized accordingly - this is not a like-for-like swap using the same fixing hardware as vinyl.
- Cutting on site: Vinyl siding is typically cut with basic hand tools; Corten steel is best cut with plasma or laser cutting equipment before delivery to the site, or with an angle grinder fitted with a metal-cutting disc for minor on-site trimming. Avoid manual hand-cutting methods intended for softer materials.
- Expansion behavior: Steel expands and contracts more with temperature swings than vinyl. Expansion joints of 3–10mm are typically needed between panels, which isn't a consideration with most vinyl siding systems.
For your architectural projects pursuing durability, aesthetics, and sustainability, choose Gnee Garden's Corten Steel Siding. Our premium corten metal siding combines all the above advantages, bringing long-lasting value and unique charm to your buildings.
Have Questions About Retrofitting Your Home With Corten Siding? Contact Us!
How to Prevent Rust Runoff From Corten Steel Siding
Corten steel naturally develops a rust-colored protective patina, but during the early weathering stage, rainwater can carry rust-colored runoff from the panels.
This should be considered when installing Corten siding near:
- Light-colored concrete or paving
- Stone walls and walkways
- Windows and doors
- Building entrances
- Drainage channels
- Other finished exterior surfaces
To help control runoff, use appropriate flashing, drip edges, drainage paths, and bottom-edge detailing. Avoid allowing water to remain trapped behind the panels or flow directly onto light-colored surfaces.
A ventilated cavity behind the siding also helps manage moisture and supports proper drainage. Corten panels should not be installed where the lower edge remains continuously exposed to standing water or soil.
The amount of visible runoff can change as the natural patina develops, so drainage should be considered during the initial design rather than treated as a maintenance issue later.
- See our related article: Corten Steel Exterior Cladding Installation & Maintenance Guide 2026
Frequently Asked Questions
Q1. Can Corten steel siding go directly over my house's existing vinyl siding?
Generally no, direct fastening over vinyl doesn't provide the flat, secure fixing surface Corten panels need. Furring strips fixed through the vinyl into the wall studs are the standard approach.
Q2. Do I need a contractor, or can I install Corten siding myself?
Basic furring-strip and fastening work is within reach for an experienced DIYer comfortable with exterior carpentry, but panel cutting, sealing details, and structural load calculations are best handled by or reviewed with a professional, especially for full-house projects.
Q3. Will my house need extra structural support for the added weight?
For most residential wall assemblies, Corten siding's added weight is manageable with standard furring and fastening, but for large panel sizes or tall walls, a structural check is worth doing before ordering materials.
Q4. Does Corten steel siding need an air gap?
A ventilated cavity is commonly used behind Corten steel siding to help manage moisture and support drainage. A typical cavity may be around 20–40 mm, depending on the wall assembly and installation design.
Q5. How do you prevent rust stains from Corten siding?
Use appropriate flashing, drip edges, drainage paths, and bottom-edge detailing to control rust-colored runoff during the early weathering stage. Extra care should be taken above light-colored paving, concrete, stone, and other surfaces that can show staining.
Q6. What fasteners should be used for Corten steel siding?
Use corrosion-resistant fasteners that are compatible with the Corten siding and the supporting structure. Stainless steel or other project-approved compatible fasteners may be used depending on the installation system and environmental conditions.
Q7. Can Corten siding be installed over wood siding?
It can be possible when the existing wood siding is sound, flat, dry, and suitable for the proposed fixing system. The panels should generally be supported by an appropriate furring or subframe system rather than relying only on the existing siding.
Why choose Gnee garden?
- Premium quality Corten steel siding panels with stable anti-corrosion patina
- Custom panel sizing to match your project's furring layout and fastening plan
- Global fast delivery with professional packaging
- Technical support for both new-build and retrofit installation projects
