When constructing a sturdy cedar fence, what’s happening underground matters just as much as what you see above it.
At Cascade, we generally recommend using steel posts for the foundation since they hold up against rot, pests, and damp Pacific Northwest weather that eats through wood. To that end, we get asked a lot if those steel posts need cement. The short answer is sometimes yes, sometimes no.
Let’s get into it and explore securing steel fence posts with or without cement, the recommended depth for different heights, and proper post spacing to ensure a long-lasting fence.
Key Takeaways:
- Steel posts work with or without cement. The right method depends on your fence and soil.
- Driven posts are cleaner, faster, and our preferred approach when the ground allows it.
- Depth and spacing are just as important.
- Heavy-gauge galvanized steel handles moisture without any extra intervention.
Fence Post Installation Methods: Cement or No Cement
You have two options when it comes to setting steel fence posts: drive them directly into the ground with a post pounder, or set them in concrete. Both options work well and the right choice just depends on what’s underneath your yard and the conditions your fence will be subject to.
Our preference is to drive, or pound, posts whenever we can. It’s cleaner, disturbs your landscaping less, and leaves you without a yard full of extra dirt when the job is done. But before we commit to either method, our project manager does a few ground prods to check two things: soil compaction and rockiness. Compaction tells us whether the ground will actually grip a post and hold it over time. Rockiness tells us how much time and effort the install will take regardless of which method we use. Those two factors together determine how we move forward.
Rocky or loosely filled soil, like what you’ll often find in newer subdivisions, can make it harder for a post to grip regardless of whether it’s driven or cemented. If the ground won’t hold a driven post, it usually won’t hold a cemented one either. That’s why we assess first and decide second.
We’ve been installing fences in Portland and the surrounding region since 1997. We already know which neighborhoods have what soil conditions, and we know how to work with whatever is underneath us.
When Concrete Makes Sense
In spots where the soil isn’t ideal for driving, using cement for steel fence posts is the right call. We set posts in 4 to 6 inches of concrete, which anchors them firmly and keeps movement to a minimum over time, especially important in areas with shifting soil or strong winds.
One thing homeowners sometimes worry about is water pooling around a cemented steel post. But steel posts and moisture are a non issue. We use heavy-gauge galvanized steel, the same material you’ll find in bridge supports and stop signs. It’s built to live outside permanently.
Related: How to Make Your Fence More Wind Resistant
How to Install Steel Fence Posts
Knowing how to install steel fence posts correctly comes down to two things: how deep they go and how far apart they sit. Get either one wrong and everything above it is working against itself.
1) Getting the Depth Right
Fence post depth is determined by fence height and installation method.
- Fences 6 feet and under: A depth of 2 feet with cement is usually enough to anchor the post without requiring excessive digging.
- Fences 7 feet or taller: Increase the depth to 3 feet. This added depth, especially with cement, stabilizes taller fences that are more susceptible to wind and need that extra hold.
- Driven posts of very tall fences: Go to 4 feet. In the case of driven posts, it compensates for the lack of concrete, while very tall fences it helps them handle heavy winds or larger decorative panels.
2) Spacing Steel Fence Posts
Even the best posts will let you down if they’re spaced wrong. Part of finding the best way to set steel fence posts is knowing that depth and spacing work together, in other words you can’t get one right and ignore the other.
Here’s our general guidance:
- Standard fences: 8 feet between posts allows for stable support for most styles and materials.
- Heavier materials or taller fences: Tighten to 6 feet to prevent sagging or shifting over time if you’re building a fence with heavier materials or extending the height beyond 8 feet.
Whatever the spacing, keep it consistent from post to post. Uneven gaps create weak points that show up as warping or tilting down the road, and those problems are a lot easier to avoid than they are to fix.
FAQs
How does the cost of cementing compare with pounding?
Closer than most people expect. Cementing requires 1-2 bags of concrete, while driving posts requires more expensive machinery and a longer post. The two largely offset each other, so the decision comes down to what’s right for your yard, not your budget.
Do steel fence posts always need cement?
Not always. Driven posts work great in the right soil conditions and are actually our preferred method when we can use them. The best approach depends on what’s underneath your yard.
Will water damage a steel post over time?
It’s a fair concern, but not one you need to lose sleep over. Steel fence posts are made with heavy-gauge galvanized steel which is designed to live outside permanently.
How deep should my fence posts go?
It depends on your fence height and how the posts are being set. As a general rule: 2 feet for fences under 6 feet, 3 feet for taller fences, and up to 4 feet for driven posts or particularly tall or heavy builds.
How far apart should fence posts be?
8 feet apart works for most standard fences. If you’re going taller or using heavier materials, we bring that down to 6 feet to keep everything solid and even.
Concrete vs No Concrete Fence Posts
So what’s our verdict on the concrete vs no concrete debate? There’s no single right answer but our preference is for driving posts directly into the ground. There are situations, like for particularly tall or heavy fences, when the best way to set steel fence posts requires cement. Ultimately, the decision needs to be tailored to your yard, your fence, and what the ground beneath can handle.
If you’re looking to install a fence in Portland, let’s talk it through. We’ve been installing fences since 1997 and our experience shows up in every project we take on.