Wind Chart Information For Flagpoles

Wind Chart Information for Flagpoles

The ASCE Hazard Tool (available at ascehazardtool.org) is designed to provide site-specific environmental hazard data, including wind speeds, seismic information, and other loads required by various editions of ASCE 7. It's a critical tool for determining design criteria for buildings and structures, including flagpoles.Here’s how to use the tool and interpret the results for your flagpole sizing:

Steps to Use the ASCE Hazard Tool: Select the ASCE Standard Version:

ASCE 7-16: This is the most recent widely adopted version and typically recommended unless local codes specify otherwise.

ASCE 7-10 or earlier: Use if a project is being reviewed under older building codes.For flagpoles, ASCE 7-16 is recommended unless local jurisdictions specifically require ASCE 7-10 or 7-05.

Input the Location
Enter the address, city, or latitude/longitude of the site.The tool will pinpoint the location on the map.

Choose the Risk Category:

For flagpoles, Risk Category I or II is most applicable.Risk Category I: For flagpoles in low-risk areas (e.g., private property or low-hazard installations).

Risk Category II: For flagpoles in public spaces or areas with higher exposure to the public.

Generate the Report
Click "Calculate" to generate the report.

The tool provides detailed information about the wind speeds and other loads for the selected site and standard.

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These guidelines are based on the 1997 NAAMM specifications from the "Guide Specifications for Metal Flagpoles", Fourth Edition

Understanding the Report: Wind Speeds

The wind speed data is critical for determining the appropriate size and structural strength of a flagpole. Here's how to interpret it:
Basic Wind Speed (V)
- Found in the report, typically expressed in miles per hour (mph).
- Example: "Ultimate Design Wind Speed: 115 mph."
- This represents the speed at which the flagpole must withstand wind pressure without failing.

Wind Speed for Specific Risk Categories
- The tool provides wind speeds tailored to the selected Risk Category and Importance Factor.
- Ensure you use the wind speed value corresponding to your flagpole’s application.

Exposure Categories
The tool does not directly list Exposure Categories (B, C, D), which relate to terrain and surrounding features (e.g., open fields, urban areas). However, this is important when applying the data:
Exposure B: Urban or suburban areas.
Exposure C: Open terrain with scattered obstructions.
Exposure D: Flat, unobstructed areas near large bodies of water.

Choosing the Right Flagpole Based on Wind Speed

Use the Basic Wind Speed (V) from the report.Cross-reference the wind speed with the flagpole manufacturer’s wind speed ratings for different pole sizes and materials.Include a safety margin for locations in higher exposure categories (e.g., Exposure D).

Wind Chart Information For Flagpoles