You've got three fence bids on the table. One says steel posts, one says treated 4x4s and one says cedar posts. Once the fence is built, you barely notice the posts. But the material you pick for them changes the number on the bid.
The short answer: Treated wood posts cost the least upfront, but they move with the weather. Galvanized steel posts cost more up front than wood posts, but they don't rot. They can rust over time. Cedar looks clean and matches a cedar fence, but it rots in the ground over time. Our pick is steel. Still, which one fits comes down to your budget, your fence and your yard.
Below we walk through what each post costs now, what it can cost later and how it holds up here. Each has trade-offs. Free estimate: (719) 330-7146.
What steel, cedar and treated posts cost
What you pay upfront
Treated wood posts have the lowest upfront cost of the three. Galvanized steel posts cost more up front than wood posts, cedar or treated.
Your estimate will show the real numbers for your fence.
What you may pay later (replacement and upkeep)
What you pay now is only part of it. Here's what you may pay later.
Cedar: wood posts in the ground need replacing at some point. The question is when. USDA Forest Products Laboratory guidance puts untreated split cedar posts at roughly 8 to 24 years in the ground, depending on climate. That's not a Colorado number. It still means planning on new posts down the road.
Steel: it costs more up front than wood posts, but it doesn't rot. It can rust over time. We use Postmaster steel posts, and they're galvanized. After many years, a steel post fence can be reskinned with new pickets and rails on the existing posts.
Treated: easy on the budget at the start. How long treated posts last depends on the ground-contact rating and the conditions. They also move with the weather, so now and then you may need to adjust or straighten a post.
Upkeep counts too. Wood above the ground does better with a finish. As our fence FAQ puts it, staining or sealing can help protect wood from moisture, UV exposure and weathering.
If your upfront budget comes first, treated is the lowest number on the estimate. You may do some adjusting as the posts move with the weather. If you want posts that match a cedar fence, cedar fits. Plan on replacing posts down the road. If you want posts that don't rot, steel fits. It costs more up front than wood posts, and it can rust over time. Steel is what we prefer. Your estimate shows the exact difference for your fence.
One tip: ask every contractor to list the post material as its own line on the bid. That way you're comparing apples to apples.
Not sure which post fits your fence and budget? Get a free estimate. Call (719) 330-7146 or request one here. We'll come out, look at your yard and lay out the post options side by side on your estimate.
Steel, cedar and treated posts side by side
Our pick is steel, but here are all three side by side. Each row is a trade-off, and the columns are in alphabetical order.
| What to compare | Cedar posts | Steel posts | Treated wood posts |
|---|---|---|---|
| Upfront cost (compared with each other) | Less than steel | More than wood posts | Lowest upfront cost of the three |
| Cost down the road | Posts get replaced eventually as rot sets in at the ground line | Can rust over time. We use Postmaster steel posts, and they're galvanized. After many years, the fence can be reskinned on the same posts. | Easy start on the budget. Movement may mean some adjusting, and posts get replaced eventually. |
| Rot and rust | USDA FPL rates the heartwood "resistant." FPL guidance: about 8 to 24 years in the ground for untreated split posts, depending on climate. Not Colorado-specific, and for posts set in soil. | Doesn't rot, but can rust. | Treated with preservative. Ground contact calls for AWPA UC4A or higher. In a semi-arid South Dakota test, many treated groups had no failures in 30 years (older preservatives). |
| Movement from moisture | Low shrinkage as wood goes, but it's still wood, so it moves some | It's not wood, so wood's shrink-and-swell doesn't apply | Can warp, twist and check as it dries, and again as it gets wet and dries out |
| Wind and frost heave | Depends on depth and concrete, same as any post | Same. Steel isn't magic if the hole is shallow. | Same |
| How it looks | Clean and sharp, and it matches a cedar fence | Looks like steel unless it's covered or framed | Looks like wood, and it's often hidden behind the boards |
| Who it tends to fit | Cedar fences where matching posts matter, and owners fine with replacing posts down the road | Owners who want posts that don't rot and are OK with a higher upfront cost than wood. Our pick. | Budget-first projects, long runs, and fences where some adjusting over time is OK |
Cedar posts: a clean look that matches, with rot as the trade-off
Cedar posts look clean and sharp, and they match the rest of a cedar fence. If your posts show, that's the draw.
The trade-off: cedar in the ground rots eventually. Here's what the research says about how long that takes:
Wet western Oregon: at Oregon State University's post farm, untreated cedar posts averaged about 23 years "under conditions favorable to decay."
Dry, cold-winter central Oregon: at the Pringle Falls Experimental Forest, none of 355 untreated split cedar fence posts had failed at 16 years, and 3 were unserviceable at 19. That soil was pumice sand, which drains far more freely than the clay in parts of Colorado Springs.
Ontario, Canada (cold winters, wetter than here): in a field test of sawn 4x4 cedar posts, 3 of the posts left unwrapped below ground failed by year 10, and 7 more failed by year 15. Many of the unwrapped posts still standing had severe decay.
We haven't found a study specific to Colorado. Every figure here is for posts set directly in soil, and none of them come from here. Treat them as a range, not a forecast for your yard.
Rot starts where the post meets the ground and moisture sits. The USDA Wood Handbook puts cedar heartwood in its "resistant" group, which generally does well above ground. It also notes decay resistance "may be less for members placed in contact with the ground." The Western Red Cedar Lumber Association itself says cedar in contact with the ground "should be treated with suitable wood preservatives." FPL also says to pick posts that are mostly heartwood.
That's the known trade-off for the look, not a defect.
Cost: less up front than steel.
Who it fits: cedar fences where matching posts matter, designs where the posts show, and owners who are fine planning to replace posts down the road. For the rest of a cedar build, see our guide to cedar privacy fence installation in Colorado Springs.
Steel posts: no rot, with rust as the trade-off
Steel doesn't rot. Rot comes from decay fungi, and they go after wood. Steel can rust, though.
Our pick is steel. We use Postmaster steel posts, and they're galvanized.
Steel posts can carry wood rails and pickets, cedar included. Set in concrete, they're solid. But steel isn't magic if the hole is shallow. Depth and concrete still do the heavy lifting.
Steel posts also let you reskin the fence. After many years, you can put new pickets and rails on the existing steel posts and end up with a fence that looks new.
Then there's the look. A steel post looks like steel, not wood, unless it's covered or framed. Ask how the posts will look from your side and from your neighbor's. If you're in an HOA, check the HOA fence rules first.
Cost: more up front than wood posts, but they don't rot.
Who it fits: owners who want posts that don't rot and are OK with a higher upfront cost than wood and the chance of rust over time. If you'd rather have an all-steel ranch look, that's a different fence. Our Buckley steel fencing post covers it.
Treated wood posts: the lowest upfront cost, made for ground contact, with movement as the trade-off
Treated posts have the lowest upfront cost of the three. They're also made to go in the ground.
Here's what "ground-contact rated" means. The American Wood Protection Association (AWPA) says ground contact calls for Use Category UC4A or higher. UC4A's typical uses include sawn fence posts. UC4B is for ground contact in severe environments and climates with high potential for deterioration. Check the end tag. It should show "AWPA U1," the Use Category, the preservative and its retention.
Properly treated posts can hold up a long time against rot. In a USDA Forest Service test near Scenic, South Dakota, every untreated pine post failed, while many groups of treated posts had no failures after 30 years. Scenic is a semi-arid spot with about 15 inches of precipitation a year. Those posts used older preservatives, not the copper-based ones sold today, so it's not a promise for today's posts. In a test near Nunn, Colorado, posts given an older double-diffusion treatment had no failures in 30 years either.
The trade-off is movement. Most pressure-treated wood is sold "green," or wet. University of Kentucky Extension notes treated posts aren't dried a second time before they ship. As the wood dries unevenly, it can check, split, warp, cup or twist. After that it keeps swelling and shrinking as it gets wet and dries out. The KDAT Lumber Association says kiln-drying after treatment (KDAT) helps, but "cannot eliminate these natural characteristics completely."
That matches what we see on jobs. Treated posts move with the weather. It's how drying wood behaves, not a defect.
Frost heave is a separate issue. That's water freezing in the soil around the hole, and it can lift any post, wood or steel. Depth and concrete do most of the work there.
Cost: the lowest upfront of the three.
Who it fits: budget-first projects, long runs, and fences where the posts are hidden or where a little adjusting over time is OK.
Colorado Springs conditions that hit every post
Freeze-thaw: the regional building code uses a 30-inch frost depth for footings. Fence posts aren't covered by those footing rules, but a good installer sets them at least that deep, in concrete. Our guide on how deep fence posts should go in Colorado Springs covers the rest.
Clay soil: the Colorado Geological Survey calls expansive soil "Colorado's most significant geologic hazard." These clays swell when wet and shrink as they dry. Soil changes block to block, so not every yard has it. Where it's there, the soil moves around any post.
Dry air: Colorado Springs averages 15.91 inches of precipitation a year (National Weather Service). The Wood Handbook shows outdoor wood in Denver drying to lower moisture than in humid cities like Louisville, Kentucky. Dry air pulls moisture out of wood. That's part of why you see wood move here.
The ground line: dry air doesn't stop rot where the post meets the soil. In the semi-arid Nunn and Scenic tests, the untreated post failures came from decay at or near the ground line.
Wind: a solid privacy fence catches wind, and the posts carry that load.
The takeaway: for all three, how the post goes in matters. That means depth, concrete and setting it plumb.
Questions to ask on any fence bid
What post material, size and depth? Are the posts set in concrete?
Treated: what ground-contact rating is on the tag (UC4A or UC4B)?
Cedar: what's the plan when the posts wear out?
Steel: how are the posts protected against rust (for example, galvanized)?
Is the post material its own line on the estimate?
Fence post FAQs
Which fence post is cheapest: steel, cedar or treated?
Treated wood posts cost the least upfront of the three. Galvanized steel posts cost more up front than wood posts, but they don't rot. Your estimate will show the exact difference for your fence.
How long do cedar fence posts last in the ground?
It depends on the soil, the moisture and how much heartwood is in the post. USDA Forest Products Laboratory guidance puts untreated split cedar posts at roughly 8 to 24 years in the ground, depending on climate. We haven't found a study specific to Colorado.
Do treated fence posts warp or twist?
They can. Treated wood is often still wet from the treatment, and as it dries it can check, warp or twist. After that, it keeps swelling and shrinking as it gets wet and dries out. Kiln-dried-after-treatment wood moves less, but it can't stop movement completely.
Do steel fence posts rust?
Steel can corrode over time. Paragon uses Postmaster steel posts, and they're galvanized.
Can you build a wood fence on steel posts?
Yes. Steel posts can carry wood rails and pickets, cedar included. Post depth and concrete still matter most. Our post-depth guide covers that.
How deep should fence posts go in Colorado Springs?
The regional building code uses a 30-inch frost depth for footings. Fence posts aren't covered by those footing rules, but a good installer sets them at least that deep, in concrete.
More on depth: how deep fence posts should go in Colorado Springs.
Get the post options side by side
Not sure which post fits your fence and budget? Get a free estimate. Call (719) 330-7146 or request one here. We'll come out, look at your yard and lay out the post options side by side on your estimate.
