The Structural Basics of LED Sign Installation
Installing an LED sign isn’t just about setting the display in place — it’s about ensuring the structure behind it is strong, safe, and built to last. Below we’ll break down the key parts required for installation, the options available, and when each is appropriate.
1. Foundations for LED Signs
Every sign starts with a foundation. The type you need depends on the size of the sign, wind load, soil conditions, and local code.
Common Foundation Types:
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Direct-Burial Pole Foundation
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A steel pole set directly into an augered hole, secured with poured concrete.
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Most common for small-to-medium signs.
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Concrete Pad with Welded Base Plate
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A reinforced concrete pad is poured, then the pole is welded to a steel base plate and bolted onto the pad.
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Useful for larger/heavier signs or sites requiring surface-level attachment.
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Anchor Bolt Foundation (Streetlight Style)
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Anchor bolts are embedded into the concrete footing. The pole’s base plate has pre-drilled holes that fit over the bolts, then nuts secure it.
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Allows for easier replacement/adjustment and is common in professional-grade installs.
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2. Poles for LED Signs
Poles provide the height and structural support for freestanding signs.
Pole Options:
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Round Steel Pipe — the most common and widely available.
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Square Tubing — provides more surface area for welded attachments.
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I-Beam Steel — stronger option for larger/heavier signs.
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Dual-Pole Structures — used when signs are especially wide or when extra wind resistance is needed.
3. Horizontal & Vertical Supports
The supports are the “skeleton” of the structure, holding the LED cabinet in place.
Materials Commonly Used:
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2” Square Steel Tubing — strong, versatile, widely available.
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Angle Iron (L-shaped steel) — useful for L-brackets and reinforcement.
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Flat Bar Steel — less common, but sometimes used in framing.
When Horizontal Beams Are Enough:
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Smaller, single-sided signs can often be supported with only horizontal beams bolted/welded to poles or walls.
When to Add Vertical Reinforcement:
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Larger/heavier signs require vertical supports to distribute the load evenly.
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For wall installs, verticals help spread weight across more of the wall surface.
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For pole installs, verticals tie back into the pole(s) to prevent sagging or twisting.
4. Double-Sided Signs
Double-sided signs add extra weight and wind resistance.
Best Practice:
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Tie both sides of the structure together with cross beams or gusset bracing.
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This prevents the two cabinets from flexing independently, which can stress welds or bolts.
5. Welding vs. Bolting
Both welding and bolting are viable methods of attaching structural members, but each has its place.
Welding:
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Strong, permanent connection.
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Best for critical load points like pole-to-beam connections.
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Requires a certified welder on-site.
Bolting (Through-Bolts / Anchors):
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Easier to adjust, replace, or inspect over time.
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Common for wall-mounted signs where through-bolts, wedge anchors, or sleeve anchors secure beams.
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Less permanent but more flexible than welding.
6. Why Engineering Matters
While general guidelines help, every project is different. Factors like sign size, wind load, soil conditions, and wall strength mean that engineered drawings are always recommended — even if your city doesn’t require them.
At LED Sign City, we provide general illustrations to guide you, but also recommend a site-specific engineered plan to ensure your installation is safe, compliant, and long-lasting.