LVL (Laminated Veneer Lumber)

What Is LVL?

Laminated veneer lumber is the workhorse of engineered wood framing. Walk into any new residential construction site and you will find LVL beams carrying loads over windows, doors, and open floor plans that dimensional lumber simply cannot span. LVL has been the standard engineered beam material since the 1970s, and production has grown to over 1.5 billion board feet annually in North America.

LVL is manufactured by peeling softwood logs — typically Douglas Fir, Southern Pine, or Yellow Poplar — into thin veneers approximately 1/10 inch thick. These veneers are dried to a uniform 6-8% moisture content, coated with phenol-formaldehyde structural adhesive, stacked with all grain running in the same direction, and bonded under heat and pressure in a continuous press. The result is a billet up to 24 inches deep and up to 80 feet long, which is then ripped to standard widths.

The critical difference between LVL and plywood is grain orientation. Plywood alternates veneer grain direction (cross-lamination) to create balanced properties in both directions. LVL aligns all veneers parallel to maximize strength along the member length — exactly what you need in a beam or header that spans between supports.

Why Builders Choose LVL

Three properties make LVL the default choice for residential beams and headers:

• Strength: LVL has allowable bending stress (Fb) values of 2,600 to 2,900 psi — roughly double that of #1 Douglas Fir-Larch solid lumber (1,500 psi). This means smaller members can carry the same load.
• Consistency: Because LVL is manufactured from randomized veneers, natural defects like knots and grain deviation are distributed uniformly. Every piece has the same engineered properties — there is no grading, no culling, no wondering if a particular beam is weaker than expected.
• Dimensional stability: LVL is manufactured at 8-10% moisture content and does not shrink, crown, twist, or bow significantly. This eliminates the crown-up/crown-down sorting that solid lumber requires and produces flatter, more predictable framing.

Common Applications

• Window and door headers: The most common residential use. A pair of 1-3/4" LVL beams (3-1/2" combined width) fits perfectly in a 2x4 wall, and a triple LVL fits a 2x6 wall.
• Garage door headers: Large openings require substantial beams. LVL handles 16-foot and 18-foot garage door spans that would require massive built-up solid lumber assemblies.
• Ridge beams: In cathedral ceiling or vaulted roof construction where rafters cannot tie together at the ridge, a structural ridge beam is required. LVL is the standard material for residential ridge beams.
• Rim board: 1-3/4" LVL serves as rim board (band joist) at floor edges, transferring vertical loads from upper floors to the wall below while providing a nailing surface for sheathing.
• Hip and valley rafters: These carry concentrated loads from jack rafters. LVL beams handle these loads at shallower depths than solid lumber.

Sizing and Selection

LVL sizing starts with three questions: What is the load? What is the span? What is the deflection limit?

Every LVL manufacturer publishes span tables and/or beam sizing software. Weyerhaeuser offers ForteWEB, Boise Cascade has BC Calc, and LP provides an online beam calculator. These tools account for the specific product properties, load duration factors, and deflection limits required by the building code.

For a rough rule of thumb in typical residential floor loading (40 psf live + 10 psf dead): a single 1-3/4" x 11-7/8" LVL spans approximately 12 feet, and a double (two plies nailed together) spans approximately 16 feet. But always verify with manufacturer tables or engineering software — there is no substitute for the actual calculation.

Installation Best Practices

• Multi-ply LVL beams (two or three pieces nailed together) must be fastened with two rows of 10d (3" x 0.128") or 12d (3-1/4" x 0.128") nails at 12 inches on center, staggered top and bottom. Some manufacturers require structural screws instead of nails for three-ply assemblies.
• Bearing length at supports must meet manufacturer minimums — typically 1-1/2" at interior bearings and 3-1/2" at end bearings. Insufficient bearing is a common field error that causes crushing at the support.
• Do not notch or drill holes in LVL without checking manufacturer specifications. The rules for hole location and size are strict because LVL is a thin-lamination product — a hole in the wrong location can initiate a failure.
• Protect LVL from rain during construction. While the phenol-formaldehyde adhesive is waterproof, sustained wetting causes edge swell in the veneers and can degrade the member over time. Wrap exposed LVL beams with building paper or housewrap if they will be exposed for more than 2 weeks.

LVL vs. Other Engineered Options

LVL competes with glulam and PSL for beam applications. Here is when each makes sense:

• LVL: Best for standard residential headers and beams up to about 24" deep. Most economical for concealed (non-exposed) beams and headers. Available at most lumber yards with short lead times.
• Glulam: Better for long spans, heavy loads, and exposed architectural applications where appearance matters. Available in wider widths (3-1/2", 5-1/8", 6-3/4") and deeper sections. Higher cost but more versatile.
• PSL: Highest strength of the three, best for columns and heavy-load beams. Available in wider widths and round columns. Most expensive per lineal foot but can often use a smaller member size.