Although certain types of light poles can last a long time, they still require regular maintenance and inspection, just like any other structure. It’s important to properly maintain light poles for several reasons:
- Safety – Light poles are installed in many types of public areas. Poles that are not properly maintained can be a dangerous hazard to those around them if they are unable to withstand outdoor conditions.
- Longevity – In order to get the most out of your investment, you’ll want your light poles to last as long as possible. Proper care and maintenance can extend their lifespan significantly.
- Aesthetics – Scratches, graffiti, rust, and corrosion can make a light pole unsightly and degrade the visual appeal of an outdoor area.
At LightMart, we pride ourselves on the quality and durability of our light poles. We have high standards when it comes to light pole manufacturing and distribution. Nevertheless, even high-quality light poles need to be maintained. This article is intended as a guide to help you keep your light pole inventory in good working order.
Understanding the life expectancy of a light pole.
Before purchasing light poles, it’s important to know that protective coatings and finishes can be applied that will increase their lifespan.
Powder-coated and/or galvanized steel poles can withstand rust and corrosion much better than standard steel poles. Galvanized steel poles also provide protection for the interior of the pole.
Powder-coated or anodized aluminum light poles will provide additional protection from corrosion. Powder-coated aluminum poles have a hard finish that is tougher and longer lasting than conventional paint. Anodized aluminum poles are stronger and more corrosion-resistant than standard aluminum poles.
The life expectancy of a light pole depends on several factors:
- The environment in which it’s used: Harsh environments will require light poles that can better withstand the elements. Windy, rainy, and snowy climates can take a toll on a pole’s structural integrity. This can lead to greater risks of rust, corrosion, and/or stress on the structure.
- Its application: Light poles that are installed in a quiet park can last a long time. Poles that are installed in industrial or marine environments are more likely to encounter harsh conditions.
- Vibration: Vibration can be destructive to a
light pole if not controlled or stopped. Areas that are susceptible to
vibrations include:
- Superstructures like garages or top floors of buildings
- Bridges and overpasses
To prevent pole vibration, consider using a vibration damper or changing the pole to a thicker/more wind-friendly shaped pole. Unlike round poles, square poles have sharp corners and flat sides. Because of this, round poles are more wind-resistant than square poles.
- Poles with no load on top: Probably the most dangerous thing you can do is install a light pole long before its light fixtures have been mounted on it. Without this load, the pole will vibrate. This will weaken or compromise the weld line or its shaft, causing catastrophic failure. Because of this, the top of the pole will be more likely to experience lateral stress during windy conditions. This will significantly decrease the pole’s lifespan, even if the pole does not fall over before its load is mounted on top.
The typical lifespan for a light pole will depend on its material.
- Steel: 15-30 years
- Fiberglass: 30-40 years
- Aluminum: 50+ years
Where and why do light poles crack?
A light pole has certain stress points that can exhibit cracks when pushed to their limits.
- Anchor base light poles have square base plates that are used to attach them to concrete foundations. During the manufacturing process, they are welded to the bottom of the pole shaft. Then, during the installation process, they are secured to the foundation with anchor bolts, washers, and nuts. These foundations can exhibit cracks when put under stress.
- Brackets and arms that are used to mount luminaires, security cameras, signs, and banners can exhibit cracks and metal fatigue.
- Hand holes are openings near the bottom of a light pole that are used to access electrical wiring inside the pole. If a light pole is pulled from the top (experiencing extreme lateral stress), it’s more likely to crack at the hand hole, not the base. Ideally, you’ll want the pole to have a flanged, reinforced hand hole which adds strength to this area.
There are certain types of environmental and external factors that are involved that can cause cracks in a light pole:
- Wind
- Moisture
- Temperature changes
- Vibration
- External impacts
- Caustic elements. These include:
- Sea salt spray
- Certain gases (For example, methane from waste treatment plants.)
- Acidic environments (For example, direct burial poles that are used in landfills. This is not recommended.)
Light Pole Maintenance: A Step-By-Step Guide
Proper maintenance of your light poles is key for the luminaire and light pole to preserve their appearance, long life, and safe operation.
Inspection Process
It’s essential to regularly inspect and maintain your light poles at least twice a year at a minimum. You’ll want to have a light pole inspection plan in place after installation.
Key areas to inspect:
Light Pole Base
- For anchor base poles, ensure that all anchor bolt nuts are in place and firmly tightened. This confirms that the base plate is properly secured to its foundation. Otherwise, the pole will begin to rock on its foundation during windy conditions. Loose anchor bolt nuts will also allow dust and moisture to collect under the base plate.
- oIt’s best to check and re-torque the anchor bolt nuts at least once a year, if necessary. You’ll need to know the recommended minimum torque rating for the bolts that you’re using so that they are not secured too loosely or too tightly. An anchor bolt projection chart can be used to find out what these values are.
- For anchor base poles, inspect the concrete foundation for potential problems. Typical issues with concrete foundations include cracks, spalls (fragmenting), and leaning foundations.
foundation crack
- If the base of the pole has been grouted (not recommended), you’ll need to have a weep hole so that water can drain to prevent it from building up. If it is allowed to build up, rust will be an issue.
rusted pole base
Mid-section
- A visual inspection of the exterior pole shaft should be performed for areas of rust or corrosion. Look for dents or hints that the structural integrity has been compromised. Ultrasonic testing can be performed for areas that can’t be visually inspected. Ultrasonic thickness gauges can be used to help determine if there has been any corrosion in the interior of the pole and to measure the remaining pole wall thickness.
- For steel poles that are not galvanized, condensation can occur in the interior of the pole and cause rust and corrosion. This is an issue even for tightly sealed polls due to day/night temperature changes.
- Ensure that any pole surface scratches are repainted/recoated so that the pole continues to be protected.
Top/Light Fixtures
- Inspect arms and brackets for metal fatigue. This can be caused by vibration, corrosion, temperature changes, or constant stress. Cracks or ruptures are signs of metal fatigue.
- Appendages can unintentionally increase the wind loads on the pole. These include banners, signs, and security cameras. They should not be added to a pole unless the pole was designed to handle the additional wind load.
- Top cap (if no tenon), ensure that it’s tight and present.
Components
- Always make sure that covers for handholes, bases, and pole tops are firmly attached so that dust and moisture do not get inside.
rusted base plate and anchor bolts/nuts
Cleaning
Regular cleaning of a light pole is important because it helps to prevent corrosion and to maintain its appearance.
Here are the recommended cleaning methods for different materials:
- If the pole is powder coated, mineral spirits can safely be used to clean off dirt, grease, and graffiti.
- If the pole is made of galvanized steel or has a natural aluminum finish (not anodized), use 600 grit sandpaper. Power washing is also recommended.
- If the pole is made of anodized aluminum, use 600 (or more) grit sandpaper.
Repainting and Protection
Light pole protection application doesn’t just begin and end during the manufacturing process. Over time, a light pole’s finish will require a bit of maintenance. Its appearance and protective coating can be subject to such things as UV exposure, harsh climate conditions, and impact-related issues such as dings, scratches, etc. This is especially true with steel light poles, which are the most common type of light pole.
It's important to repaint steel poles as needed. Not just for appearances, but for protection from rust and corrosion. Touch-up paint should be used to cover scratches on these types of poles. These scratched areas are more vulnerable to the elements and the paint adds a layer of protection. For powder-coated steel poles, it’s recommended that you use oil-based paints.
You can also use a rust inhibitor for added protection or naval jelly to remove existing rust. They won’t necessarily improve appearances, but they will extend the lifespan of a pole.
Repairing and Replacing Components
Another light pole maintenance factor to consider besides the pole itself is the various components that are included. These include:
- Pole caps
- Base covers (for round and square poles)
- Hand hole covers
It’s always best to inspect these important items and repair or replace them as needed.
If there are vibration issues with a light pole, vibration dampers can be used.
vibration damper
LightMart’s Quality Light Poles: Built to Last
LightMart supplies factory-direct light poles and accessories for all types of lighting projects. Our quality products are durable, and our customer service has the expertise you need to quickly plan and accomplish any type of project.
We have the ability to quickly ship light poles from our industry-leading inventory or we can handle specialized projects with our made-to-order manufacturing capabilities.
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