Using Decking for a Fence? The Unbelievable Truth Revealed
You have a vision for a new fence—something robust, stylish, and perhaps a little different from the standard picket fence lining your street. The question arises: can you use decking boards for fencing? The short answer is yes, but the long answer is far more complex and crucial for the success and longevity of your project.
Using deck boards for a fence is an increasingly popular choice for homeowners seeking a modern, durable barrier. However, this non-traditional approach comes with a unique set of challenges and considerations that, if ignored, can lead to structural issues, unexpected costs, and a fence that doesn’t stand the test of time. This guide will explore the critical details you need to know before committing to this robust fencing solution.
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The Core Problem: Deck Boards vs. Fence Pickets
The fundamental issue lies in the design and purpose of these two distinct building materials. Deck boards are engineered to be laid flat, supported by a substructure of joists to handle significant weight from foot traffic, furniture, and snow. Fence pickets, on the other hand, are designed to be installed vertically, are much thinner, and are primarily intended to create a visual barrier with some resistance to wind.
Ignoring these differences is where homeowners run into trouble. Simply substituting one for the other without modifying the fence’s core structure can lead to problems. The immense weight of deck boards can overwhelm a standard fence frame, causing sagging rails, strained posts, and eventual failure.
Why Even Consider Deck Boards for a Fence?
Despite the challenges, the appeal of a deck board fence is undeniable for several reasons. Many are drawn to the bold, contemporary aesthetic of a horizontal fence, for which the long, straight lines of decking are perfectly suited. Others are looking for a more substantial and durable barrier that feels more permanent than a traditional picket fence.
Additionally, some homeowners may have leftover decking material from a previous project, making it a seemingly cost-effective option. However, it is vital to understand the structural modifications required to ensure this “cost-saving” measure doesn’t turn into an expensive repair job down the line. To better understand the material differences, it’s helpful to compare fence boards vs deck boards directly.
A Deep Dive into the Structural Challenges
The primary hurdle to overcome when using deck boards is managing their substantial weight. A standard pressure-treated 5/4″ x 6″ x 16′ deck board can weigh over 25 pounds. When you multiply that by the number of boards needed for even a single fence panel, the load becomes significant.
This “dead load” places constant stress on the entire fence structure. A framework built for thin cedar or pine pickets is simply not engineered to support this kind of weight. The result can be horizontal rails that bow significantly over time, posts that lean, and fasteners that pull loose.
The Unspoken Threat: Wind Load Dynamics
A factor that is rarely discussed but critically important is the impact of wind on a solid deck board fence. A traditional picket fence allows wind to pass through the gaps between the boards, reducing the overall force exerted on the structure. A fence built with tightly spaced or overlapping deck boards, however, acts like a solid sail.
In high-wind areas, this creates immense lateral pressure on the fence posts and their concrete footings. Without proper reinforcement, this force can lead to posts cracking at the base or, in extreme cases, the entire fence being pushed over. This consideration is paramount for ensuring the long-term stability and safety of your investment.
The Comprehensive Solution: Building It Right
Successfully using deck boards for a fence requires a shift in mindset from building a simple barrier to engineering a robust, load-bearing structure. This means reinforcing every component of the fence, from the footings to the fasteners.
Step 1: Fortify the Foundation
The entire strength of the fence begins underground. Fence post footings must be deeper and wider than standard fence specifications to handle the combined dead load and potential wind load. For a typical 6-foot-tall deck board fence, posts should be set in concrete footings that are at least 36-48 inches deep, depending on your local frost line, and have a diameter of 10-12 inches. Using larger posts, such as 6x6s instead of 4x4s, is highly recommended for their superior resistance to bending and torsion.
Step 2: Reduce Spans and Reinforce Rails
To prevent the horizontal rails from sagging under the weight of the decking, you must reduce the distance they span. Post spacing should be limited to a maximum of 6 feet, rather than the more common 8 feet used for standard fences. For added security, especially on longer spans, installing a vertical mid-span support block between the rails can provide essential reinforcement.
Furthermore, using stronger rails is a necessity. Instead of standard 2x4s, consider using 2x6s laid on their edge. This orientation provides significantly more vertical stiffness and resistance to bowing over time.
Step 3: Choosing and Installing the Boards
Whether you choose pressure-treated wood, cedar, or composite decking, the installation method is key. For horizontal fences, it’s crucial to leave a small gap of at least 1/8 inch between each board. This allows for wood expansion and contraction with changes in humidity and provides some relief for wind pressure.
For vertical installations, the process is more straightforward, but the structural requirements for posts and rails remain the same. Always use high-quality, exterior-grade screws designed for decking. These offer superior holding power compared to nails and will resist pulling out under the weight of the boards.
Material Showdown: Deck Boards vs. Fence Pickets
Understanding the key differences in materials is crucial for making an informed decision. The following table breaks down the typical characteristics of standard deck boards compared to traditional fence pickets.
| Attribute | Deck Boards | Fence Pickets |
|---|---|---|
| Nominal Thickness | 1″ to 1.5″ (5/4″ is common) | 5/8″ to 3/4″ |
| Width | 5.5″ (for a “6-inch” board) | 3.5″ to 5.5″ |
| Weight (per sq. ft.) | Significantly Heavier | Lighter |
| Treatment | Rated for ground contact/horizontal use | Rated for above-ground use |
| Primary Purpose | Structural (load-bearing) | Non-structural (barrier) |
| Cost | Higher per board | Lower per board |
Cost and Market Considerations
While using leftover deck boards might seem like a way to save money, building a new fence from scratch with decking will almost always be more expensive than using standard fence pickets. Deck boards themselves are more costly, and the required structural upgrades—larger posts, deeper footings, stronger rails, and additional hardware—add to the overall budget.
It is important to factor these additional material and labor costs into your decision-making process. Keeping an eye on market trends can also be beneficial, as lumber prices fluctuate. Exploring questions like will fence prices go down can help you time your project for maximum cost-effectiveness.
Composite Decking: A Modern Alternative
Composite decking offers an excellent, albeit more expensive, option for fencing. It is incredibly durable, resistant to rot and insects, and requires very little maintenance. The color is consistent throughout the material, meaning scratches are less visible, and it never needs to be stained or painted.
However, composite boards share the same structural challenges as their wood counterparts: they are heavy and can be susceptible to sagging over long spans if not properly supported. All the same structural reinforcement principles—stronger posts, shorter spans, and robust rails—apply when using composite decking for your fence.
Final Verdict: Is a Deck Board Fence Right for You?
Building a fence with decking boards is a project that offers a stunning, modern, and highly durable result when executed correctly. It is an excellent choice for homeowners who prioritize a robust aesthetic and long-term performance over initial cost savings. The key to success is to approach the project with an understanding of the engineering principles involved.
If you are prepared to invest in the necessary structural upgrades—stronger posts, deeper footings, reinforced rails, and shorter spans—you can create a truly unique and long-lasting feature for your property. However, if budget is the primary concern or you are looking for a quick and simple installation, a traditional fence built with standard pickets may be the more practical choice. By respecting the materials and their intended purposes, you can ensure your new fence is not only beautiful but also safe and sound for years to come.
