Understanding 2024 IRC Deck Beam Span Charts
The 2024 International Residential Code (IRC) has introduced significant updates to deck construction, including new requirements for beam span calculations. This article delves into the 2024 IRC deck beam span charts, their significance, and how to interpret them for safe and compliant deck construction.
Why the 2024 IRC Deck Beam Span Charts Matter
The 2024 IRC deck beam span charts are crucial for ensuring the structural integrity and safety of decks. They provide clear guidelines on the maximum allowable spans for beams based on the type of material used and the load they need to support. By adhering to these charts, builders and homeowners can prevent deck collapses and other structural failures.
Understanding Deck Loads
Before diving into the 2024 IRC deck beam span charts, it's essential to understand the different loads that decks are subjected to. These include:

- Live loads: The weight of people and furniture on the deck.
- Dead loads: The weight of the deck structure itself, including the decking, railings, and beams.
- Wind loads: The force exerted by wind on the deck and its components.
- Snow loads: The weight of snow accumulation on the deck (in regions with significant snowfall).
Interpreting the 2024 IRC Deck Beam Span Charts
The 2024 IRC deck beam span charts provide maximum allowable spans for beams based on the material type and the total load they need to support. The charts consider the combined effect of live, dead, wind, and snow loads. Here's a breakdown of the charts:
Beam Material Types
The charts categorize beams into four material types:
- Wood: Includes sawn lumber and engineered wood products like I-joists.
- Steel: Includes steel joists and steel beams.
- Aluminum: Includes aluminum joists and beams.
- Composite: Includes composite lumber and other composite materials.
Maximum Allowable Spans
The charts provide maximum allowable spans for each material type, ranging from 6 to 24 feet, depending on the load and material. For example, a 2x10 wood beam can span up to 12 feet when supporting a total load of 40 psf (pounds per square foot), but only 6 feet when supporting a total load of 100 psf.

Calculating Beam Size and Spacing
Once you've determined the maximum allowable span for your deck beam based on the 2024 IRC deck beam span charts, you'll need to calculate the appropriate beam size and spacing. The IRC provides tables for determining beam size based on span and load, as well as guidelines for beam spacing.
Additional Considerations
While the 2024 IRC deck beam span charts provide valuable guidance, it's essential to consider other factors when designing and constructing decks:
- Concentrated loads: Ensure that beams can support concentrated loads from posts, railings, and other deck components.
- Post spacing: The IRC limits post spacing to 6 feet on center for decks with a live load of 40 psf or less, and 4 feet on center for decks with a live load exceeding 40 psf.
- Connections: Use appropriate connectors and fasteners to ensure that beams are securely attached to posts and other components.
Always consult with a licensed professional or the local building department if you're unsure about any aspect of deck construction. By adhering to the 2024 IRC deck beam span charts and other relevant guidelines, you can ensure that your deck is safe, durable, and compliant with building codes.
More Details
ICC Digital Codes is the largest provider of model codes, custom codes and standards used worldwide to construct safe, sustainable, affordable and resilient ...

International Residential Code (IRC). BEAM. BEAM. POST. POST. TABLE R507.6. DECK BEAM SPAN LENGTHSa, b (ft. - in.) SPECIESc. SIZEd. DECK JOIST SPAN LESS THAN OR ...

04.02.2026 ... You would think that the maximum span is 7-7, as that lines up with 12 and 0 for a 2-2x8 beam. MARC Train Track ...

a new approach was approved for 2024. In the new beam sizing table, the heading of the beam span tables where the “joist span” (with fully assumed cantilever) ...

Maximum allowable spans for wood deck beams, as shown in Figure R507.5, shall be in accordance with Table R507.5. Beam plies shall be fastened with two rows of ...

... Deck-Construction-Guide-2015-IRC.pdf. TOPIC. DCA6 REFERENCE. FILL IN REQUIRED ITEMS. 1 JOISTS. Size, spacing (center to center), and span length? ... 5 BEAM TO ...

15.07.2025 ... ... span tables for joists and beams and tables of post sizing limitations and connection methods.

This one-page guide highlights common deck construction requirements and key updates in the 2024 IRC. ... • Beam Span chart – R507.5. Ledger Board ...

Beams shall be permitted to cantilever at each end up to one-fourth of the allowable beam span. Deck beams of other materials shall be permitted where designed ...

05.09.2024 ... ... deck beam span tables that references another table: 507.5(5). ... In the 2024 IRC, the column heading previously titled “effective joist span ...

2024-11-02. Jake is a professional man. His ... Deck Construction Joist Span Charts. Prescriptive Residential Deck Construction Guide Based on the 2021 IRC.

29.07.2024 ... 7/29/2024. Maximum Deck Beam Span. (Reference IRC Table 507.5). 60 psf live load or 70 psf ground snow load c. BEAM SPECIES d. BEAM SIZE e.

01.01.2026 ... ... 2024 International Residential Code (IRC). ... Deck Frame: o Joist Span: The horizontal supports underneath the deck boards are the joists.

The 2024 IRC clarifies that all joists, beams, posts, decking, and stair stringers must be made from either pressure-treated wood or from durable species, such ...

Results: · 2024 CCWD · 2005 Design Values for Joists and Rafters · 2005 Span Tables for Joists and Rafters · 2024 Span Tables · 2021 CCWD.

through a typical deck and identifies the relevant building-code requirements (2018 2021, 2024 IRC/IBC) and connection options. Our deck-code guide can be a ...

16.12.2024 ... Beams must follow Tables R507.5(1-4) in the IRC, depending on the live load and ground snow load on the deck. The maximum beam span length ...

with city staff to determine if it is subject to additional requirements. 2024 IRC ... • Spans of joists, beams, decking, footings and dimensions of all material.

Change Type: Modification 2024. Significant Change: The deck beam span table is updated by adding options for deck joist spans and cantilevers. 2024 Code ...

• Reproduced from Prescriptive Residential Exterior Wood Deck Span Guide (CWC). Allowable Joist Spans (meters). Joist Size. (mm). 300mm Joist Spacing. 400mm ...
