Looking for the right precast concrete light pole foundation supplier? The only function of a light pole foundation is to resist movement (settling, tilting or cracking around the base) and maintain a vertical position (perfectly upright) for decades in the face of wind loads and vibration. Otherwise, no one will know! If not, it’s not the idea of a precast foundation, it’s the idea of the designer and the manufacturer of the foundation! This guide will teach you how to assess a precast concrete light pole foundation supplier in order to get foundations that will ensure every light pole will stand upright, rather than leaning or cracking in the first few years after installation.
When It Comes to Selecting a Supplier, There Is More Than Just Base Dimensions and Price
The initial criteria most buyers consider is base size, weight and price per unit. That’s a good starting point – but it does not cover how the supplier is calculating the unit and reinforcing it to resist the actual wind and vibration loads that a pole and fixture combination will place on it, at your actual site.
The load on light pole foundations is surprisingly high for their size. The load is always the same and repeated; a tall pole with a large fixture is a lever where the force of the wind is amplified at the base, much more than the force of the pole itself. A supplier that takes foundation design seriously as any kind of structural engineering rather than a “concrete block with bolts in it” takes into account the true pole height, fixture size and local wind conditions. One that doesn’t will provide a base that appears sturdy on the ground, but will begin to crack, tilt and start to lose bolts in a few storm seasons.
Understand the Types of Foundations for Any Project Precast Concrete Light Pole Foundation Supplier
It’s helpful to understand a project’s type of foundation before comparing suppliers, as pole height and fixture weight, along with site conditions, will dictate what is appropriate.
Standard Roadway and Parking Lot Foundations
Common street/parking lot light poles are supported at moderate heights by standard foundations. These should be designed to fit standard pole and fixture configurations and have anchor bolt patterns that are a perfect fit for the pole manufacturer’s base plate.
High-Mast Lighting Precast Concrete Light Pole Foundation Supplier
In tall poles, usually located at highway interchanges or at large open areas, the wind loading at height is a much larger design consideration than it is at shorter masts, and is known as high-mast foundations. These should have much larger, reinforced bases and proper consideration of soil bearing capacity, as the effects of a foundation that is too small for a high mast are more severe.
Decorative and Pedestrian-Scale Foundations
In streetscape, park, or plaza applications, shorter poles (often ornamental) are supported by a decorative or pedestrian scale foundation. These focus on the finished and neat above-grade appearance as well as the structural purpose, and they are often above-grade and visible.
Custom and Site-Specific Precast Concrete Light Pole
Custom foundation solutions are designed for non-standard poles, special site conditions, or soil types that do not apply to a standard foundation. These must be done by a supplier who is prepared to perform actual site-specific calculations, rather than use a general foundation design and hope it is sufficiently similar to work.
After you identify the appropriate category based on the factors you listed above, that’s when you can start to narrow down the list of suppliers that make products you can trust, with real engineering behind them.
Inquire About Their Structural Design and Load Calculations
A supplier with a good understanding of the manufacturing process will make a calculation of the size of the foundation based on the actual load calculations found in your pole height, fixture weight, and local wind speed data, rather than a generic size that is “supposed” to be adequate. This should involve a clear specification of the design wind load, the resulting overturning moment the foundation is to resist and reinforcement sized for that moment.
Specifically ask them what wind loading they are designing for, what the foundation is designed for and what soil bearing capacity they assume and if they can provide you with the arithmetic calculation for the specific project as opposed to a catalogue size. If a supplier responds with actual numbers and is willing to take the time to validate those numbers with your project requirements, they are listening to you. It’s a person who just tells you what size pole to use without any calculations or analysis, that deserves probing.
Examine How They Handle Anchor Bolt Placement and Accuracy
When it comes to light pole foundations, one of the most frequent (and most significant) issues in installation is the accuracy of the anchor bolts. Inquire about the accuracy of their anchor bolt placement when they cast, the accuracy they use in their bolt pattern and bolt protrusion from the pole to the casting deck, and if they check anchor bolt placement with your casting pole manufacturer’s base plate template before casting.
Even a foundation slightly outside of tolerance may cause problems in installing the pole without modifying the foundation, which can be an expensive compromise of the structural integrity of the connection. Request specifically how the supplier can verify the accuracy of the bolt template for your particular pole, rather than a standard template for the industry.
Review Their Manufacturing Quality Control
Two nominal size foundations can be of different actual sizes due to different casting methods. For every such unit, ask questions about how it is cast, what the curing procedure and time are, and what checks are performed, such as checking and verifying the reinforcement placement and checking the bolt pattern before the unit is dispatched.
The concrete cover over the reinforcement is very important here because the foundations are usually in the ground and will be subject to moisture from soil throughout the life of the structure. What cover does the supplier provide and how does he/she ensure it when manufacturing, as poor cover will result in corrosion of the reinforcement in the long term, which will be seen only when the foundation has already been damaged.
Request Project-Specific Engineering, Not a Standard Catalogue Size
A good supplier will offer to verify the foundation size and design to match your existing pole height, fixture specifications and local wind and soil conditions and not just supplying you the closest catalogue item. That should cover checks against your project’s wind loading needs, anchor bolt pattern being matched with your specific pole manufacturer, and advice on soil type that may call for a foundation size other than the one assumed in the catalogue.
Those suppliers who are working with your project parameters will detect any discrepancies between the catalogue basics and your real site before the foundation is laid. When a supplier provides only a standard size chart, which is based on the height of the poles, but is not willing to cross verify any details of the project, your only option is to go on your own estimation that there won’t be any discrepancy between what they assume and what you have.
Examine the Installation and Handling Requirements
The sizing and installation requirements for foundations depend on the size and application. Roadway foundations are usually of a manageable size and can be handled with standard site equipment, but high-mast foundations are significantly larger and heavier and therefore necessitate the use of proper lifting equipment, and care in planning excavations from the start.
Inquire with your supplier about lifting and handling regulations that may apply to your foundation, the recommended backfill and compaction, and if they will supply instructions or work with contractors that have experience installing their foundation. A surprise on site that a foundation requires equipment or depth that was not budgeted is a costly occurrence.
Check Their References and Track Record
They will tell you what a supplier says is possible with their foundation design based on the design calculations and reinforcement specifications. Poles are installed to tell you what they actually delivered. Request examples of foundations provided for comparable pole lengths and foundation conditions and information about their performance — the poles remain plumb, no cracking or settling after many years of service, including during severe wind events.
Their engineering skills are demonstrated far better by a supplier who has a proven history of keeping poles straight and stable under real wind conditions than by any catalogue listing.
Signs to Look Out For Precast Concrete Light Pole Foundation Supplier
The few indicators listed below are common to less reliable foundation suppliers:
- Not providing supporting load calculations for a suggested foundation size.
- Providing unclear responses to questions about the tolerance of the anchor bolts.
- Making vague references to having checked the foundation design against your particular pole.
- Not wanting to confirm the design against wind and soil conditions on site.
- Pricing that is significantly lower than the competition but lacking any explanation of the difference.
None of these should automatically exclude a supplier, but if two or three of these appear at the same time, it’s a good sign to pause before you invest any more time into the project.
Connecting the Dots Precast Concrete Light Pole Foundation Supplier
The best precast concrete light pole foundation supplier will not only make the right size foundation, but will also design and reinforce it according to your pole, fixture and site conditions, while placing the anchor bolts accurately for the specific installation. Correctly done, the foundation performs exactly as it is intended to: keeping every light pole perfectly upright and stable through storm after storm for the entire life of the installation.