Fence and Deck Post Lights

Measure the post before choosing the light

A post light is only as good as its fit. Fence and deck posts are usually sold by nominal size, and a nominal 4x4 post measures about 3.5 inches square, which is why solar caps are often listed as 3.5 in or 4x4. Check whether the cap sits on top, slides over or screws to the side, and whether your post is square, round or capped with a ball. Larger fixtures on stems need a flat top and a way to feed cable through the post.

A 120 V fixture or a 1.2 V solar cell

Rated voltage separates two very different products. Line-voltage fixtures run on mains power, often listed from 120 V up to 277 V, and give constant light but need wiring in a weatherproof box, ideally by a qualified electrician. Solar caps carry a small rechargeable cell, often listed at 1.2 V, so they need no cable but glow dimly and depend on the panel seeing the sky. Large units listed as 100-watt or higher street lights suit poles and parking areas, not a garden fence post.

Questions about Fence and Deck Post Lights

What size post cap do I need for a 4x4 fence post?

A nominal 4x4 post is about 3.5 inches square, so look for caps listed as 3.5 in or 4x4. Measure your own post at the top, because weathered or trimmed lumber can differ, and round or chamfered tops need a different cap.

Can I wire a 120 V post light myself?

Rules differ by region, and many require a licensed electrician or a permit for fixed outdoor wiring. The work involves shutting off the circuit, a weatherproof connection and ground-fault protection. If you are unsure, choose a solar cap, which needs no wiring.

Why do solar post lights get dimmer over time?

The rechargeable cell wears with each charge cycle, and a dirty or shaded panel charges less. Wipe the panel, move the light out of shade if you can, and replace the cell if the model allows it.