Can You Install a Vinyl Fence Without Concrete? Exploring Alternatives

To find out whether concrete is universally required for vinyl fence post installation, I combed through over 20 vinyl fence installation manuals. I found that manufacturers generally have one thing in common.

Manufacturers unanimously require vinyl fence posts to be installed into a concrete filled post hole. Setting vinyl posts into concrete provides a consistent footing to ensure the posts will remain inline and true for years to come. Concrete should fill the post hole up to 3-4 inches from the top. The post hole diameter should be about 3 times the post’s width, and the depth should be ⅓ the post’s above-surface height.

Many how-to resources simply emphasize the importance of deferring to the manufacturer’s installation instructions for installing a vinyl fence. However, not all vinyl manufacturers, as I painstakingly found out, make their installation guidelines readily available. For example, some local manufacturers deal mostly with local AFA (American Fence Association) licensed contractors and rarely communicate with the DIY client. They assume the installation technicians are properly trained.

For the DIY installer, knowing that there are common installation procedures emphasizes the importance for proper installation methods.

Installing a Vinyl Post: It’s All About that Base

With all that said, if you are considering installing a vinyl fence without concrete, it would be prudent to understand that other methods are not recommended for the installation of the entire fence. And, though a situation may warrant the use of an alternative installation method, the support needs of the fence do not change.

The dimensions and concrete fill requirements for the vinyl fence post hole are established to provide a long-term solid footing for the post. This concrete base will provide:

Long-Term Stability to prevent the posts from dislodging and developing wobble issues.
Long-Term Resistance to Erosion and Upheaval (soil expansion) and Settling (soil retraction) to ensure resilience against the elements and the natural movement of the earth and soil.
Long-Term Aesthetics to ensure the posts remain in consistent alignment and looking sharp for years to come.

Does Adding Support Inside a Vinyl Post Replace the Need for Concrete? It’s Still All About that Base

If there is a specific reason why an alternative to concrete is being considered for a vinyl fence install, it is important to NOT overlook the need to provide a solid base for the post.

Simply adding additional support inside the post, such as: metal inserts, concrete/rebar, and lumber (not recommended), does NOT replace the need to provide a solid and stable footing. See more about reinforcing the vinyl post here.

What is the Best Alternative to Concrete When Installing a Vinyl Fence Post?

Hard-Packed Coarse Aggregate

In the research mentioned in the introduction above, out of the twenty sets of installation instructions reviewed, only one company provided an addendum suggesting that hard-packed coarse aggregate could be used in the place of concrete.

Pros:

Similar base qualities to concrete: deep, thick, and heavy with the coarse gravel gripping tightly to the vinyl.
Cost savings: Coarse aggregate can usually be bought by the yard and thus becomes much more affordable than purchasing individual bags of concrete. Although, a cost-savings vs. labor analysis would need to be carefully evaluated as the install could be far more labor intensive.
Environmentally friendly: being a strong proponent of environmental conservation, designating an entire blog post to vinyl fence and concrete environmental impacts (and other considerations) will be a source that I’ll reference here once available.

Cons:

Hard packing hardships: Installing posts with hard-packed coarse aggregate comes with its own set of complications–such as: the hard packing.
- Vigorous tamping and hard-packing the coarse aggregate around the post is the key for this to be an effective concrete alternative. This becomes tedious and extremely labor intensive–haaarrd work–over the course of multiple post installs.
Tapping Out: Each tap will push the post in and out of alignment. Getting the post plumb and in-line is challenging. If not careful, the bottom of the post can be tapped too far out of alignment and the entire post may have to be pulled–a scenario where the removal of the aggregate would also be required and the process would have to be started all over.

*Side note: removing hard-packed coarse aggregate straight out of a 12”x30” hole is. . .HDH!! Hole-Digging-Hell

Exploring 3 Additional Fence Installation Methods Without Using Concrete

There may be other alternatives to concrete that could be explored for setting the vinyl fence post. However, no other methods are mentioned in any of the manufacturer recommendations for the installation of an entire fence project..

Fence Post Expanding Foam

Costs around $10 per 33 fl oz bag. One bag replaces two 50lb bags of concrete. Sets in 3-4 minutes. Most functional in dry rocky soil and not suitable for wet or soft soil environments. Intended to be used to complete small projects and repairs. Does not claim to replace the strength properties of concrete.

Metal Fence Post Anchors

Bolt down post support: intended to be bolted down onto concrete slab, concrete footing, or possibly into bedrock.
- Definitely a handy option if installing a post flush against the siding of a home where the foundation’s footing may prevent the post from being installed at an appropriate depth.
No-dig ground anchors: screwed or pounded in–depending on the product.
- Expensive: $30-$80 depending on the product. Some come with self leveling features to help with plumbing up the post.
- Driven into the ground using rebar or a sledge hammer.

Regular Soil

Installing vinyl posts with the same fill dirt going in as the fill dirt that came out is the “meh!” method of installation.
- It is definitely a money saving approach but . .I’m not sure why it would be used holistically for an entire fence install–as it forces the argument:
  - “. . .if you’re going to invest so much into the vinyl material, why wouldn’t you spend a little bit more money on doing it right???”
- To maximize this procedure’s effectiveness, all of the rocks can be gathered from soil as it’s removed from the hole. Then, once the post has been inserted, the rocks can be concentrated and jammed up all around the post.
  - If the fill dirt is extremely hard packed (and I mean, EXTREMELY HARD PACKED) as it’s returned to the post hole, the post is given the best chance it possibly has with this method.

LAST NOTE REGARDING ALTERNATIVES:

**Unique layout obstructions may provide an appropriate case for the use of these alternative methods as they may be equipped with their own situational merits. However, an argument to use such methods for an entire fence install would have to be constructed around how it could establish, replace, or enhance a long-lasting sturdy base for the fence line.

IMPORTANT CONCRETE CAVEATS

There are a few important caveats that may prevent a post (or posts) from being installed into concrete.

UTILITY LINES

In the very first step of planning a fence install, all manufacturers recommend having the local utilities come to label and mark out the utility lines.
Calculate post layout and make adjustments to avoid, if at all possible, having a post installed right on or near a utility line.
Dig holes carefully and manually (no auger) near utility lines. There may be a specific distance from utility lines where an auger must not be used–stay safe and check with your local utilities company.
If your layout cannot avoid installing a post near a utility line, check with your utilities company for guidance and specific distance requirements–you may have to consider installing the post without concrete.

Landscaping Challenges

Unique landscape characteristics may warrant an alternative method for installing a vinyl post.
- Trees, roots, rocks, and other landscaping features may require layout alterations or installation without the use of concrete.
Becoming familiar with other installation methods may not be a bad idea–as it may allow you to creatively work around these obstacles.

Building Codes

Always check local building codes, HOA bylaws and CCRS to ensure that a vinyl fence install and the installation methods will be in accordance.

**ONE FINAL NOTE: Installing a Vinyl Fence is HARD Work!**

This is a project you will want help with. Do not do it alone. Consider the amount of heft and heave associated with the overall project as you’ll be required to haul potentially tens of thousands of pounds of dirt, concrete, and materials through the course of the entire project.

I’ve written a whole blog about things to consider before taking on the project here. It really is back breaking labor and I strongly urge you to obtain multiple quotes from contractors in order for you to be able to perform a proper cost savings analysis by doing it yourself. You may also learn a lot from the local contractors that may help you find ways to make the process more efficient and more affordable.