Attaching cedar fence boards correctly is the difference between a fence that endures decades of harsh weather and one that sags, warps, or falls apart in a few years. Cedar is a premium choice for fencing due to its natural rot resistance, lightweight nature, and classic aesthetic, but these benefits are only realized when the boards are installed with precision. This guide walks through the essential steps, from material selection to the final tightening, ensuring your fence is both beautiful and built to last.
Selecting the Right Cedar Boards and Hardware
The foundation of a successful installation begins long before the first nail is driven. Choosing the correct grade of cedar is crucial for the project’s longevity and appearance. For fence boards, #1 grade cedar is ideal as it is knot-free and has minimal sap content, which allows for better paint or stain adhesion. Avoid lower grades if you plan to stain the fence, as the knots can bleed tannins and create a mottled appearance. Equally important is the selection of fasteners; standard steel nails or screws will corrode over time when in contact with the tannins in cedar. Instead, opt for coated or stainless steel screws designed specifically for exterior wood applications, as they provide the necessary corrosion resistance and superior holding power.
Understanding Grain Direction and Expansion
Before laying a single board, you must understand how cedar reacts to moisture. Wood expands and contracts across the grain (width-wise) rather than along its length. If you install boards too tightly against one another or against a rigid structure like a concrete post, the wood has no room to move. This pressure leads to warping, buckling, or the boards pushing each other out of alignment as the seasons change. Always leave a small gap—typically the width of a standard pencil—between the end of the board and any immovable surface, as well as between adjacent boards where possible. This gap allows the cedar to “breathe” and move naturally without compromising the structure’s integrity.
Preparation and Post Setting
Leveling the Foundation
Even the highest quality boards will look crooked if the posts are not set correctly. Begin by ensuring all posts are plum and aligned. Use a line level or a string line stretched tightly between the end posts to establish a consistent height reference across the entire run. The posts must be buried to a sufficient depth in concrete—generally one-third of the post’s total height—to prevent tipping. Before the concrete sets, double-check that the posts are perfectly straight. Adjustments made at this stage are infinitely easier than trying to correct a fence line after the boards are attached.
Installing the Rails
Rails are the horizontal supports that hold the fence boards vertically in place. It is generally recommended to install rails before attaching the cedar fence boards. Typically, rails are positioned at the top, middle, and bottom of the post. For a standard 6 to 6 foot privacy fence, the middle rail is usually placed at 3 feet from the ground. The rails should be attached using the same coated or stainless steel fasteners, ensuring they are flush with the inside edges of the posts to create a clean, uniform surface for the boards to sit against.
Attaching the Boards: The Header and Starter
To maintain a professional look and ensure the fence is square, start by installing a “header” board at the very top of the rail and a “footer” or “starter” board at the bottom. These boundary boards act as guides for the rest of the installation. Align the header with the top edge of the rail, ensuring it is level. Because cedar tends to have natural variations in width, use shims—thin pieces of wood or plastic—behind the header and footer if necessary to keep the face of the fence perfectly even. Once these two boards are secured with screws through the rails, the line for the entire fence is set.
Spacing and Securing the Boards
With the guides in place, you can move down the length of the fence, lifting each board onto the rails. Position the board so that the bottom edge aligns with your footer line. Use plastic or wood shims on the sides where the board meets the post to maintain consistent, pencil-width gaps. These gaps are vital for water drainage and airflow, which prevents the wood from rotting at the contact points. When securing the board, drive screws just above and below the rail—approximately 6 to 8 inches from the top and bottom of the board. Avoid placing screws directly in the middle of the board, as this is where the wood is most likely to split due to natural movement.
Dealing with Warping and Final Checks
Even with careful selection, some cedar boards may arrive slightly bowed or twisted. Never force a warped board into place; doing so will create tension that pulls the entire fence line off-level. Instead, use temporary braces or clamps to hold the board in the correct position while you drive the screws. As you progress, regularly check your work with a level and a straightedge. Look for consistency in the gaps between boards and the alignment of the tops. If you notice any wobbling or soft spots, revisit the rail attachments; the issue is usually a loose rail rather than a problem with the board itself.
Finishing Touches
Once every board is secured and the line of the fence is true, remove all the plastic shims used during installation. The cedar will now begin to weather naturally, shifting from its initial honey tone to a soft silver-gray. Because the boards were installed with expansion gaps and fastened with corrosion-resistant hardware, it is ready to handle the elements. Whether you choose to leave it to weather naturally or apply a transparent sealant to preserve the original color, the foundation of a stable, long-lasting fence has already been established through meticulous attachment.
