Steel posts.
If you’re just looking for the answer, it’s steel posts by a long shot. The second you put wood posts into the ground, you start the clock on a replacement.
Fence posts are the single biggest factor in how long your fence holds up. Get that part right and everything else takes care of itself.
Keep reading if you want to better understand why steel wins when it comes to fence posts.
Key Takeaways:
- Modern pressure treated posts fail in 6 years or less.
- When a wood post fails, you’re paying for demo, disposal, and a partial rebuild. Not just a post.
- Steel posts outlast every wood component attached to them, often by decades.
- The pile driver system we use holds stronger than concrete.
- The upfront cost difference is real. The long-term cost difference is bigger.
Why Steel Wins the Wood vs. Steel Fence Durability Debate
The two most common options for fence posts in the Pacific Northwest are pressure treated wood posts and galvanized steel posts.
For the past 20+ years, we’ve been recommending steel posts.
Here’s why:
What Changed with Pressure Treated Wood
In 2003, the use of chromated arsenicals in wood treatment products was banned. Prior to that ban, treated wood posts could last around 20 years. No one found a replacement chemical that works as effectively for wood treatment, and now wood posts simply do not have the same level of rot resistance.
Modern wood fence posts typically fail in 3 to 7 years. Here at Cascade, we’ve even seen wood posts completely rot in 1 to 2 years on fences we built ourselves. Since we know the installs were done right, we can confidently point to the material as the problem.
Why Steel Is the Superior Material for Fence Posts
Steel is a cost-effective fence post material that will last virtually forever with little to no maintenance.
Thanks to the wet climate here in the Pacific Northwest, rot is a given. Wood fence posts quietly rot from the ground up until your fence starts leaning. Steel posts don’t have that problem.
The foundation used for steel posts is another advantage. Whereas wood posts rely on concrete foundations to secure fence posts, we install steel posts with a pile driver system. The pile driver drives a steel channel 3 feet into the ground for a 6-foot fence. Long-term that’s much better for holding up a fence.
Side-by-Side Comparison: Wood vs Steel Fence Posts
| Wood Posts | Steel Posts | |
|---|---|---|
| Lifespan | Modern pressure treated posts last roughly 6 years or less. We've seen posts fully rotten within 1-2 years on fences we built. | Essentially forever. Chain link runs 60-70 years; steel post systems outlast all the wood components above them. |
| Durability | Susceptible to rot, decay, and pests like termites and carpenter ants. The damp Pacific Northwest climate accelerates deterioration significantly. | Galvanized steel resists corrosion, rot, and insects. Pile driver channels are driven 3 feet into the ground. High winds don't stand a chance! |
| Maintenance | Regular staining, sealing, and occasional repairs required. Wood posts don't really get "maintained," they just quietly rot from the ground up… | Zero. Once installed, there's nothing to stain, seal, or treat. |
| Aesthetics | Natural, rustic look. Can be stained or painted to match the fence design. Blends well with the Pacific Northwest environment. | Sleek and modern. Can be fully covered with cedar boards with no visible posts at all on the finished fence. |
| Upfront Cost | Lower upfront. Around $14 per post. | Higher upfront. Around $22 per post. The investment pays off by eliminating replacement cycles. |
| Long Term Cost | When a post fails in year 6 or 7, you're paying for demo, disposal, and a partial rebuild long before the rest of the fence is done. | Posts stay in the ground when pickets and rails eventually need replacing. The next fence goes up on the same foundation. |
| Local Sourcing | Often locally sourced in the Pacific Northwest, reducing transportation footprint. | Not locally sourced. However, the long lifespan and zero maintenance offset the higher production footprint over time. |
| Our Take | Not what they used to be. The treatment formula changed when arsenic was banned, and performance has suffered. The single biggest failure point of a wood fence. | We always recommend steel posts and we prefer PostMaster fence posts. The heavy gauge steel and shape make it the strongest post on the market. |
Pros and Cons of Wood and Steel Posts
| Pros and Cons of Wood Fence Posts | Pros and Cons of Steel Fence Posts |
|---|---|
| Pros | Pros |
| Natural, rustic look that blends with the Pacific Northwest environment. Can be stained or painted to match your fence design. Lower upfront cost, around $14 per post. Often locally sourced, reducing transportation footprint. | Essentially permanent and outlasts every wood component above it. Zero maintenance, nothing to stain, seal, or treat. Immune to rot, insects, and moisture, ideal for the Pacific Northwest. When pickets and rails eventually need replacing, the posts stay put. Can be fully covered with cedar with no visible posts on the finished fence. Pile driver system holds stronger than concrete long-term. |
| Cons | Cons |
| Modern treated posts last 6 years or less. We've seen them fully rotten in 1-2. Rot and decay are inevitable in the damp Pacific Northwest climate. Vulnerable to termites and carpenter ants. Post failure means demo, disposal, and a partial rebuild, not just a post swap. Requires regular staining, sealing, and repairs over its short life. | Higher upfront cost, around $22 per post. Steel production has a higher carbon footprint than wood which is offset over time by its lifespan. |
Wood Posts Are Cheaper Upfront But More Expensive Long-Term
Steel posts are much more expensive upfront. Wood fence posts can run you about $14 per post, while steel fence posts are around $22.
That’s a big difference, but keep in mind that you’ll be replacing wood posts sooner. Replacement is where the real cost shows up.
When a wood post fails after 6 or 7 years, you’re not just replacing the post. The pickets, rails, and hardware attached to it usually have to come down too. The result is paying for demo, disposal, and a partial rebuild long before the rest of your fence has reached the end of its life.
Meanwhile, steel posts outlast the wood components above them, so when the pickets and rails eventually need replacing, the posts stay put and the next fence goes up on the same foundation.
Over a 20 to 25 year window, a wood post fence will likely need at least one full post replacement cycle. A steel post fence won’t.
If you’re weighing the pros and cons of wood and steel fence posts, you’ll quickly discover that steel has many more pros than cons going for it.
Read More: How Much Does a Fence Cost?
When Steel Fails It’s Almost Always Situational
Steel posts rarely fail. Steel doesn’t rot, it doesn’t get eaten by insects, and moisture doesn’t compromise its structural integrity.
When steel does fail, it’s almost always situational: a car backing into the fence, a tree coming down on it, or a post driven into compromised soil that shifts over time. Surface rust can develop at the ground line if the coating gets nicked during install, but that’s an installation issue, not a material one.
For practical purposes, the post will outlast the pickets and rails attached to it, often by decades. When it’s time to rebuild the fence above, the foundation is already there waiting for you.
Frequently Asked Questions
Which is better long-term: wood or steel fence posts?
Steel, without question. Pressure treated wood posts are the single biggest failure point of a wood fence.
How do maintenance and replacement costs compare over time? Steel posts win on both fronts. Maintenance on a steel post is essentially zero, there’s nothing to stain, seal, or treat. Wood posts require regular maintenance, which includes staining and sealing, and will eventually need to be replaced.
How long do wood fence posts typically last in the Pacific Northwest?
Roughly 6 years or less for modern pressure treated posts. Around 20 years for the older arsenic-treated posts that are no longer legal.
How long do steel posts last?
A properly installed steel post will outlast your fence, your next fence, and quite possibly your house.
For a real-world reference point: chain link fences, which use the same galvanized steel construction, routinely last 60 to 70 years. Aluminum fencing is considered essentially permanent. Your fence boards will need replacing long before the posts ever become a concern.
What causes wood posts to fail most often?
Wood rot.
Do steel posts ever fail?
Rarely, and almost never in the way you might expect. When it does happen, it’s usually the result of physical impact, installation into compromised soil, or surface rust from a coating damaged during install, not a material failure.
Get an Instant Fence Estimate!
Because of wood’s limited lifespan, we wholeheartedly recommend using steel posts. In our experience, it’s always cheaper in the long run with a steel post as you will never have to replace rotten posts. That said, we’re happy to work with whatever material makes sense for your project. Try out our Fence Calculator to get an instance fence estimate today!