Ontario Building Code Beam Span Chart: Easy Guide & Table

Understanding Ontario's Building Code Beam Span Chart

The Ontario Building Code (OBC) provides a comprehensive set of guidelines for the construction and design of buildings in the province. One of the key aspects covered in the OBC is the span of beams, which is crucial for ensuring the structural integrity and safety of buildings. The OBC beam span chart is a vital tool for architects, engineers, and builders to determine the maximum allowable span for various beam types and loading conditions.

What is the Ontario Building Code Beam Span Chart?

The OBC beam span chart is a table that outlines the maximum allowable spans for various types of beams, based on the loading conditions and the material used. The chart is designed to ensure that beams can safely support the loads they are expected to bear, preventing structural failures and ensuring the longevity of the building.

Why is the Beam Span Chart Important?

The beam span chart is a critical component of the OBC as it helps to ensure the safety and stability of buildings. By adhering to the maximum allowable spans outlined in the chart, builders can minimize the risk of structural failures, which can lead to costly repairs, injuries, and even fatalities. Moreover, compliance with the OBC is a legal requirement for all buildings in Ontario.

Understanding the OBC Beam Span Chart

To use the OBC beam span chart effectively, it's essential to understand its structure and the factors that influence the maximum allowable span. The chart is organized based on the following factors:

• Beam Material: The chart categorizes beams based on the material used, including steel, wood, and concrete.
• Loading Conditions: The chart considers different loading conditions, such as live loads (LL) and dead loads (DL), to determine the maximum allowable span.
• Beam Depth: The depth of the beam also plays a crucial role in determining its maximum allowable span.

How to Read the OBC Beam Span Chart

To read the OBC beam span chart, follow these steps:

1. Identify the beam material and depth.
2. Determine the loading condition (LL, DL, or a combination of both).
3. Locate the intersection of the beam material, depth, and loading condition in the chart.
4. Read the maximum allowable span from the corresponding cell.

Factors Affecting Beam Span

While the OBC beam span chart provides a general guideline for determining the maximum allowable span, several factors can influence the actual span required for a specific application. These factors include:

• Support Conditions: The type of support (simple, continuous, or cantilever) can affect the maximum allowable span.
• Slope and Camber: The slope and camber of the beam can also influence its maximum allowable span.
• Snow Loads: In regions with heavy snowfall, snow loads must be considered when determining the maximum allowable span.
• Wind Loads: Wind loads can also impact the maximum allowable span, particularly for long-span beams.

Ontario Building Code Beam Span Chart Example

Here's an example of how the OBC beam span chart might look for steel beams with a depth of 300 mm:

In this example, the maximum allowable span for a steel beam with a depth of 300 mm under live loads (LL) is 6.0 meters for a simple span, 9.0 meters for a continuous span, and 3.0 meters for a cantilever.

Conclusion

The Ontario Building Code beam span chart is an invaluable tool for architects, engineers, and builders working on projects in Ontario. By understanding and adhering to the maximum allowable spans outlined in the chart, professionals can ensure the structural integrity and safety of buildings, while also complying with the legal requirements set forth in the OBC.