LVL Beam Span Charts (2024): Your Complete Guide to Sizing & Load Capacity

Planning a deck, room addition, or simply opening up your living space? LVL beams offer exceptional strength for ambitious projects, but selecting the right one is crucial. This guide decodes LVL beam span charts, providing the knowledge you need to confidently choose the perfect beam, whether you’re a seasoned builder or a weekend warrior. Let’s get started!

Understanding LVL Beams and Span Charts

LVL beams (Laminated Veneer Lumber) are engineered wood products renowned for their strength and stability. They’re created by layering thin wood veneers under pressure, resulting in a beam that resists warping and twisting—ideal for long, uninterrupted spans. But how do you determine the right size? That’s where LVL beam span charts come in. These charts, provided by manufacturers, are essential tools that help you select the appropriate beam size based on various factors.

What is an LVL Beam?

LVL beams are the unsung heroes of modern construction, providing the backbone for stunning open-concept designs. They are commonly used for:

Floor and ridge beams: Supporting floors and roofs.
Joists: Providing support for flooring systems.
Headers: Spanning openings like doors and windows.
Lintels: Supporting masonry above openings.
Rafters: Forming the framework of roofs.
Trusses: Providing structural support for roofs and other structures.
Rim boards: Providing a perimeter frame for floors and roofs.
Scaffold planks: Creating safe working platforms.

Their layered construction offers superior strength and dimensional stability compared to conventional lumber, minimizing the need for support columns and enabling larger, more flexible spaces.

Decoding the Span Chart

LVL beam span charts may appear complex, but they’re surprisingly straightforward once you grasp the key elements:

Span: The distance between the supporting points of the beam (e.g., walls, posts).
Load: The total weight the beam will support. This includes the dead load (weight of the building materials) and the live load (weight of occupants, furniture, snow, etc.).
Beam Size: The dimensions of the LVL beam (width and depth). Common widths include 1-3/4″, 3-1/2″, 5-1/4″, and 7″. Depths can range from 5-1/2″ to 24″ and even larger with custom orders. Note that the width dimension can correspond to typical lumber sizes, for example a 1-3/4″ wide LVL could represent a 2×6, 2×8 or larger depending on the depth.

The chart helps you match these three critical factors – span, load, and beam size – to ensure a safe and structurally sound design.

Factors Influencing Span

Several factors beyond span, load, and size influence an LVL beam’s capacity:

Wood Species and Grade: The type of wood used in LVL manufacturing affects its inherent strength. Higher grades generally indicate greater strength and stiffness, potentially allowing for longer spans.
Support Conditions: How the beam is supported at its ends significantly impacts its performance. A beam fully supported on both ends behaves differently than one that is notched or cantilevered. Continuous beams, supported at multiple points, generally offer greater load-carrying capacity.
Load Type and Distribution: The type of load matters. Concentrated loads (e.g., a heavy appliance) stress the beam differently than distributed loads (e.g., the weight of the flooring). The distribution of the load also plays a role; a uniformly distributed load is handled differently than a point load.

Calculating Your LVL Beam Span

While span charts offer initial guidance, precise calculations are essential for optimizing your design and ensuring safety.

Using Span Charts

Start by identifying your project’s requirements: the desired span, the estimated load (including both dead and live loads), and the support conditions. Then consult the manufacturer’s span chart. Locate the row corresponding to your load and support conditions, and then find the column matching your desired span. The intersection of these two will suggest the required beam size.

Online Span Calculators

Online span calculators provide more refined calculations tailored to your project’s specifics. These tools can be incredibly helpful, but always double-check the results against manufacturer data.

Consulting a Structural Engineer

For complex projects or when dealing with unusually high loads or unconventional support conditions, consulting a structural engineer is highly recommended. They can perform detailed analyses, account for various load scenarios, and ensure compliance with building codes. This expert guidance ensures structural integrity and peace of mind.

Manufacturer Resources and Building Codes

Leading manufacturers like Boise Cascade (with their Versa-LAM LVLs) offer extensive resources, including detailed span charts, technical guides, and design values. These resources are invaluable for accurate sizing and understanding load capacities. Building codes are the ultimate authority on safety and compliance. Always adhere to local and national building codes for your project.

Rules of Thumb and Their Limitations

You might encounter rules of thumb, such as multiplying the beam depth (in feet) by 20 to estimate the span. While helpful for initial approximations, never rely solely on these simplified methods for final design decisions. Precise calculations, using manufacturer data or engineering software, are essential for structural integrity.

How Far Can You Span an LVL Beam?

The maximum span of an LVL beam isn’t a fixed number; it depends on a dynamic interplay of factors.

Beam Size (Width and Depth): The larger the beam’s dimensions, the longer the potential span. Depth has a more significant impact than width on span capacity.
Wood Type and Grade: Different wood species and grades possess varying strengths, influencing the allowable span. Higher grades typically translate to longer spans.
Load (Dead and Live): The total load, including dead load (building materials) and live load (occupants, furniture, snow), significantly affects the maximum span. As load increases, the allowable span decreases.
Support Conditions: How the beam is supported at its ends plays a crucial role. Fully supported beams can span further than notched or cantilevered beams. Continuous beams, supported at multiple points, can also achieve longer spans.

To accurately determine the maximum span for your project, consult manufacturer span charts, utilize online calculators, or consult a structural engineer, especially for complex scenarios. These resources incorporate all relevant factors to provide precise and safe span calculations.

What Size LVL Beam for a 20 ft Span?

While a 3-1/2″ x 11-7/8″ LVL is sometimes used for a 20-foot span, the actual required size hinges on the load. Never rely on generalizations; always perform accurate calculations.

Load Considerations: The Critical Factor

The total load—dead load plus live load—dictates the required beam size. A 20-foot span for a deck supporting typical loads (people, furniture) might use a 3-1/2″ x 11-7/8″ LVL. However, a rooftop terrace with heavier loads (hot tubs, planters) would likely need a larger beam, possibly a deeper beam in the 10-12 inch range, or even a custom beam.

Finding the Right Size

Manufacturer Span Tables: Resources like Boise Cascade’s Versa-LAM LVL Size Chart are invaluable. These tables provide precise sizing information based on the specific LVL product and the expected load.
LVL Beam Calculators: Online calculators can provide quick estimations, but always validate the results with manufacturer data.
Consulting a Structural Engineer: For critical projects or when in doubt, a structural engineer can make definitive recommendations, ensuring safety and compliance.

Cost and Material Optimization

Larger beams equate to higher costs. However, undersizing a beam can lead to structural issues and costly repairs down the line. Optimizing the beam size involves finding the sweet spot between strength, cost, and project requirements. Understanding the relationship between load, span, and beam size empowers you to make informed decisions.

Can an LVL Span 40 Feet?

Spanning 40 feet with an LVL beam is achievable, but it requires careful planning and consideration.

Factors Influencing a 40-Foot Span

Beam Dimensions (Depth and Width): A deeper and wider beam is crucial for long spans. Depth has a more pronounced impact on span capacity.
Load Capacity: Accurately calculating the total load is paramount. Underestimating the load can lead to dangerous structural issues.
Support Conditions: Securely anchored supports are essential. The type of connection (bolted vs. nailed) also affects the beam’s performance.
LVL Specifications: Different LVL products have varying strengths. Consult manufacturer specifications for 40-foot span feasibility.

Resources for 40-Foot Spans

Manufacturer Span Tables: Essential for determining the feasibility and requirements of a 40-foot span. Boise Cascade’s VERSA-LAM® LVL span tables are a good example.
Online Calculators: Helpful for estimating beam size, but always verify results against manufacturer data.
Rule of Thumb (Depth x 20 = Span): Provides a rough starting point but should never replace precise engineering calculations. For instance, a 2-foot deep beam might span 40 feet, but verify this with manufacturer data.

Cost and Complexity

40-foot spans often involve higher costs due to specialized manufacturing, transportation, and the potential need for professional engineering services.

Alternatives to a Single 40-Foot Span

Consider these alternatives:

Intermediate Supports: Adding support columns or walls reduces the span, allowing for smaller, less expensive beams.
Alternative Materials: Steel beams or glulam may offer better performance or value in some cases.

Curious about the potential reach of your rafters? Check our rafter span chart. By carefully considering these factors and utilizing reliable resources, you can confidently plan your project, whether it involves a modest 20-foot span or an ambitious 40-foot expanse. Always prioritize safety and consult with professionals when needed.

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Mark Soldy

Aficionado of interior design with a keen eye for style and innovation. As a guy deeply passionate about crafting captivating spaces, he blends creativity with functionality to breathe life into every room