An LVL beam is a type of engineered wood made by bonding multiple thin layers of wood veneer together under heat and pressure. The abbreviation stands for Laminated Veneer Lumber. It’s one of the most widely used engineered wood products in residential and commercial construction, commonly found wherever a strong, straight beam is needed to span an opening or support a load above.
How LVL Beams Are Made
LVL starts as thin sheets of wood veneer, typically peeled from logs on a rotary lathe. Each veneer layer is roughly 1/10 of an inch thick. The sheets are coated with a strong adhesive, stacked so that the wood grain in every layer runs in the same direction (lengthwise), then pressed together at temperatures between 250 and 450 degrees Fahrenheit. The result is a dense, uniform slab of lumber that can be cut to almost any size.
Douglas fir is the most common species used for LVL in the United States, along with Southern pine and Yellow poplar. In other parts of the world, manufacturers use Radiata pine (New Zealand) and rubberwood (Southeast Asia). The adhesive is typically phenol formaldehyde, a waterproof resin that gives LVL its structural bond. Some manufacturers use urea-formaldehyde resins, which are cheaper but produce higher formaldehyde emissions. For structural beams used in framing, phenol formaldehyde is the standard.
Why Builders Choose LVL Over Solid Lumber
Solid lumber has natural imperfections: knots, grain irregularities, and internal stresses that can cause warping, twisting, or splitting over time. LVL largely eliminates these problems. Because it’s built from many thin layers, any individual defect in one veneer sheet gets absorbed by the surrounding material. The finished product is straighter, more predictable, and more consistent from one beam to the next.
LVL is also stronger than comparable solid lumber in practical terms. While clear, defect-free Douglas fir has an impressive stiffness rating, real-world lumber is graded with reductions for knots and other flaws. LVL maintains stiffness values around 2.0 million psi (sometimes higher), which often exceeds what standard dimension lumber delivers once grading is factored in. That higher stiffness means less deflection, so floors feel firmer and headers don’t sag over time.
Perhaps the biggest advantage is length. Solid lumber is limited by the size of the tree it came from, and anything over 20 feet is hard to source. LVL beams are available in lengths up to 80 feet because the veneer sheets can be staggered and overlapped during manufacturing, creating a continuous piece with no weak splices.
Common Sizes
LVL beams come in a range of standardized dimensions. Typical widths (thicknesses) include 1½”, 1¾”, 3½”, 5¼”, and 7″. The 1¾” width is particularly popular because two of them laminated together equal 3½”, which matches a standard 2×4 wall perfectly. Depths range from 9½” up to 24″, with common options at 9½”, 11⅞”, 14″, 16″, 18″, and 20″.
When a single beam isn’t wide enough or strong enough for the load, builders stack multiple plies side by side and fasten them together. A “3-ply LVL” made from three 1¾” pieces creates a 5¼” wide beam, for example. This modular approach lets builders dial in exactly the strength they need without ordering a custom product.
Where LVL Beams Are Used
You’ll find LVL in several key spots in a building’s frame:
- Headers and lintels: The horizontal beam above a window, door, or garage opening is one of the most common applications. LVL handles the load transfer around these openings without sagging.
- Floor and roof beams: Long spans across open rooms, vaulted ceilings, or load-bearing walls often call for LVL because it can carry heavy loads over distances that solid lumber can’t.
- Rim boards: Some manufacturers produce a cross-ply version of LVL (with some veneer layers rotated 90 degrees) specifically for rim board applications along the perimeter of floor systems.
- Hip and valley rafters: In roof framing, the long diagonal rafters that carry loads from multiple common rafters benefit from LVL’s consistency and available lengths.
Bearing and Support Requirements
LVL beams need proper support at each end where they rest on a post, wall, or column. The minimum bearing length is 1½”, but most real-world installations require more. A typical 3-ply beam carrying 10,000 pounds of design load, for instance, needs about 3½” to 4″ of bearing length depending on the beam width and the material it’s resting on. Every beam also needs lateral support at its bearing points to prevent it from rolling or twisting under load. These requirements vary by manufacturer and load, so the structural plans for your project will specify the exact dimensions.
Moisture and Weather Exposure
LVL is designed for dry interior use. While the phenol formaldehyde adhesive itself is waterproof, the wood veneers will absorb moisture if left exposed to rain. Prolonged water contact causes swelling, and repeated wetting and drying cycles degrade the beam’s mechanical properties over time. During construction, some temporary exposure to weather is unavoidable, and LVL can tolerate brief periods of rain. But it should be covered or protected as soon as practical, and it should never be used in permanently exposed outdoor applications without a protective coating or enclosure.
Research into water’s effects on LVL confirms that moisture increases swelling and reduces strength properties like shear and impact resistance. Some manufacturers offer LVL treated for higher moisture environments, but standard construction-grade LVL assumes the beam will be enclosed within a wall, floor, or roof assembly where it stays dry.
How LVL Compares to Other Engineered Wood
LVL is sometimes confused with glulam (glued laminated timber), but they’re different products. Glulam is made from full-thickness boards stacked and glued together, while LVL uses paper-thin veneers. Glulam is often left exposed as a finished architectural element, while LVL is almost always hidden inside the framing.
LSL (Laminated Strand Lumber) is another engineered alternative. Instead of veneer sheets, LSL uses long wood strands compressed with adhesive. LSL works well for rim boards and shorter headers, but LVL generally offers higher stiffness and bending strength for beam applications. PSL (Parallel Strand Lumber) is yet another option, made from long veneer strands. Each product fills a slightly different niche, but LVL remains the go-to choice for most beam and header applications because of its strength-to-cost ratio and wide availability.
Cost and Availability
LVL costs more per linear foot than standard dimension lumber, but that comparison misses the point. A single LVL beam often replaces what would otherwise require multiple solid lumber pieces sistered together, or it spans a distance that solid lumber simply can’t. In header and beam applications, the total installed cost is often comparable once you account for the labor savings and reduced material waste. LVL is stocked at most lumber yards and building supply stores, and custom lengths can be ordered within a few days in most markets.