While Natures Composites fencing is designed and recommended to be installed by burying the posts into the ground and setting them in concrete, surface mounting is an option when burial isn’t possible — for example, when installing over an existing concrete slab or patio.
For a surface-mounted installation, the basic concept is simple: reinforce a Natures Composites 5x5 post with a pressure-treated 4x4 inside, secure the assembly using an appropriate heavy-duty 4x4 post base and concrete anchors, then attach the U-Posts included with your Modern fence panels to the 5x5 post. Composite shims can be used as needed to create a snug fit.
Important: All Natures Composites wind and hurricane-performance testing was conducted using buried-post installations. Published wind ratings do not apply to surface-mounted installations.
Modern vs. Traditional Systems
For Modern Fence and Modern Ranch Rail, your panels already include the U-Posts needed to hold the boards or rails. For surface mounting, you will need to purchase additional 5x5 Commercial Grade Posts to position between the panels. The included U-Posts attach to these 5x5 posts.
For Traditional Ranch Rail, the system already uses 5x5 posts, so you do not need additional 5x5 posts solely for surface mounting.
What You'll Need
- Natures Composites 5x5 Commercial Grade Posts
- Pressure-treated 4x4 wood inserts
- Heavy-duty post bases designed for nominal 4x4 lumber
- Appropriate concrete anchors and through-fasteners
- Composite shims, as needed
One example of this style of post base is the Simpson Strong-Tie E-Z Base FPBB44. Always confirm that the bracket, anchors and mounting method selected are appropriate for your substrate, fence height, site conditions and local requirements.
How to Surface Mount Your Fence
1. Plan Your Layout
Mark each post location and confirm your panel spacing before drilling into the concrete.
2. Prepare the 4x4
Cut a pressure-treated 4x4 to the appropriate length. This will reinforce the 5x5 composite post from inside.
3. Insert the 4x4
Slide the 4x4 inside the 5x5 Commercial Grade Post. Use composite shims as needed to eliminate gaps and create a snug fit.
4. Surface Mount the Assembly
Position the heavy-duty 4x4 post base so its vertical bracket sits inside the 5x5 composite sleeve and around the pressure-treated 4x4.
Use an appropriate through-fastener to secure the composite sleeve, bracket and 4x4 together. Anchor the base plate to the concrete and make sure the finished post is plumb and rigid.
5. Install the Fence
For Modern systems, attach the U-Posts included with your panel kits to the surface-mounted 5x5 posts. Then install your boards or rails and continue following the standard installation guide for your model.
Remember: Burial Is Still Recommended
Surface mounting is a useful alternative when digging isn't possible, but burying the posts and setting them in concrete remains our recommended installation method.
Surface-mounted performance depends on factors including the existing concrete, anchors, bracket, fence layout and site conditions. Where possible, incorporating a supported corner or securing an appropriate end of the fence to a suitable structural wall can also help reduce movement.
