LVL Beams

Laminated veneer lumber is engineered wood built for one job: carrying load without the headaches solid sawn lumber gives you. It’s produced by bonding thin wood veneers together in a large billet so that the grain of all veneers is parallel to the long direction, then the billet is sawn to desired dimensions depending on the end-use application. The result is a beam that doesn’t twist, doesn’t shrink, doesn’t split.

Here’s the thing every buyer needs to understand first. LVL is a proprietary product, and therefore the specific engineering properties and sizes are unique to each manufacturer. LVL does not have a common standard of production and common design values. That means you don’t eyeball an LVL beam the way you might a 2x10. You size it off the manufacturer’s span tables or the ICC-ES evaluation report, matching the modulus of elasticity (E) and bending stress (Fb) to your actual span, load, and deflection limit.

For Montana builders, two things matter most. LVL carries long roof spans and headers under heavy snow loads, and it stays dimensionally stable through the wide temperature and humidity swings that warp ordinary lumber. But it’s strictly a dry-use product — more on that below.

Why LVL Outperforms Solid Sawn Lumber

The strength comes from how it’s made. After exterior adhesive, usually phenol formaldehyde, is applied to the surface of each veneer sheet, they are assembled and pressed at temperatures ranging from 250 to 450 degrees Fahrenheit. Heat and pressure, parallel grain, bonded for the life of the structure.

That parallel grain is the whole point. The grain of each layer of veneer runs in the same long direction, with the result that LVL can be loaded on its short edge (strong axis) as a beam or on its wide face (weak axis) as a plank. This type of lamination is called parallel-lamination and produces a material with greater uniformity and predictability than engineered wood products fabricated using cross-lamination, such as plywood.

Defects are the enemy of predictable strength, and the manufacturing process handles them. LVL is a solid, highly predictable, uniform lumber product due to the fact that natural defects such as knots, slope of grain and splits have been dispersed throughout the material or have been removed altogether during the manufacturing process. A knot you can’t see can’t surprise you mid-span. LVL is one of the strongest wood-based construction materials relative to its density, and because it is manufactured with homogeneous quality that has a minimum number of defects or even distribution of defects, mechanical properties of the final product can be predicted.

The species varies, but the usual suspects show up. LVL is commonly fabricated using wood species such as Douglas fir, Larch, Southern yellow pine and Poplar. Some grades run differently — one product line consists of aspen or a combination of birch and aspen veneers laminated with the grain of the veneers parallel to the length of the member.

One more practical edge worth knowing. Because they have no camber and strength is consistent throughout, LVL products have no top or bottom side. No guessing which way it goes in. With better properties, these beams support heavier loads and longer spans than comparable glulam or dimension lumber products.

Grades, Sizes, and Matching the Beam to the Load

Grade is stated as E and Fb together. Western Building Center carries Boise Cascade Versa-Lam in a 2.0/2.1E 2800 DF grade across several sizes, plus Weyerhaeuser Microlam in the deeper beams. The two number sets you’ll see referenced — like 1.8E 2650 and 2.1E 3100 — are the stiffness (E) and bending stress (Fb) values you compare against your span table.

Thickness drives how you build a beam. The most common thickness of LVL is 1-3/4 inch, from which wider beams can be easily constructed by fastening multiple LVL plies together on site. Stack plies and you nest into standard wall framing — two or three sections joined together form 3-1/2-inch or 5-1/4-inch members, which readily nest into 2x4 or 2x6 framed walls as headers or columns.

Common depths and their typical roles:

Spec	Range / Common Values
Ply thickness	1-1/2”, 1-3/4”, 3-1/2”, 5-1/4”
Most common single ply	1-3/4”
Common beam depths	9-1/2”, 11-7/8”, 14”, 16”, 18-3/4”, 23-7/8”
Manufactured thickness range	3/4” up to 7”
Depth range (per ESR product)	1-3/4” up to 72”
Available lengths	up to 80 ft; common 48, 56, 60, 66 ft

Those depth and length figures come straight from manufacturer data. Commonly used LVL beam depths are 9-1/2 in, 11-7/8 in, 14 in, 16 in, 18-3/4 in and 23-7/8 in. Other widths and depths might also be available from specific manufacturers. LVL is available in lengths up to 80 ft, while more common lengths are 48, 56, 60 and 66 ft.

The long lengths are something dimension lumber simply can’t match, and there’s a reason. Because LVL is made with scarfed or lapped jointed veneers, it is available in lengths far beyond conventional lumber lengths. That’s what makes it the answer for a long ridge or an open-plan span.

How do you actually size it? Don’t assume. The manufacturer’s own engineering tools and reports exist precisely for this. Sizing software performs engineering analysis to help size beams, joists, columns, studs and tall walls; the user enters the member geometry, adds loads and other relevant data and then selects a product for analysis to identify which products meet the demands of the application. Verify your design values against the span table or the ICC-ES report for the exact product you’re buying.

Where LVL Fits in the Frame

The applications are the ones carrying real load. Typical uses include rafters, headers, beams, joists, studs, columns and I-joist flange material. More specifically for LVL: headers and beams, hip and valley rafters, scaffold planking, and the flange material for prefabricated wood I-joists. Open-plan support beams, floor girders, and roof ridges all fall right in its wheelhouse.

It also shows up as the backbone of other engineered products. LVL is intended for structural applications such as beams, headers, joists, rafters and columns, and serves as components in built-up structural members such as flanges for I-joists, chords for trusses and laminations for glue laminated members.

Most of the time it stays out of sight. LVL is mainly used as a structural element, most often in concealed spaces where appearance is not important. Finished or architectural grade appearance is available from some manufacturers, usually at an additional cost.

Worth knowing how it stacks against glulam, since the two get cross-shopped for beams. LVL takes the heavier loads and longer spans. Glulam wins on cost and looks — one common glulam line runs 20% to 30% less expensive than LVL, and it’s the product of choice for value engineering and a great choice for short door and window headers. The split is straightforward: LVL for capacity and concealed structure, glulam where the beam stays exposed and the budget is tight.

Installation and Storage — Don’t Void the Warranty

This is the part that gets contractors in trouble in a wet climate. LVL is a dry-use product, full stop. LVL products shall be installed in dry-use applications only, per their respective ICC-ES/APA ESR evaluation reports. The number to remember: tabulated stresses are for LVL installed in covered, dry locations where the maximum moisture content of the LVL will not exceed 16 percent. Push past that and it must not be used in applications where it will obtain a moisture content greater than 16 percent.

In Montana, that means keep it covered. LVL should be protected from the weather during jobsite storage and after installation. Wrapping of the product for shipment to the job site is important in providing moisture protection, and end and edge sealing of the product will enhance its resistance to moisture penetration. Even with its stability, neglect bites back — the product may result in some defect, such as warping, if it is not properly stored in the warehouse.

On cutting: length is fine, freelancing is not. Except for cutting an LVL member to length for installation during construction, cutting, drilling, or notching of the LVL member is outside the scope of the evaluation report. Or put plainly — all special cutting, notching or drilling should be done in accordance with the manufacturer’s recommendations. When in doubt, get engineering approval before the saw or the drill touches the beam.

Fastening and connections follow the report too. Design and installation must comply with the report, the manufacturer’s published installation instructions and the applicable code, and if there’s a conflict between the installation instructions and the report, the report governs. Keep the documents on site — drawings and/or manufacturer’s published installation instructions for the erection and installation on each job must be available on the jobsite at all times during installation.

Do it right and the product stands behind itself. All Boise Cascade BCI joist, Versa-Lam LVL, and AJS joist products are covered by a limited lifetime warranty for the expected life of the structure.

Frequently Asked Questions

What size LVL beam does a given span need? Size it against the manufacturer’s span table or ICC-ES report for that specific product, matching the E (stiffness) and Fb (bending stress) values to the span, load, and deflection limit. LVL is a proprietary product, so the specific engineering properties and sizes are unique to each manufacturer, and LVL does not have a common standard of production and common design values. Manufacturer sizing software handles this by accepting geometry and loads as inputs to find a product that works.

Can LVL get wet? No. Tabulated design stresses are for LVL installed in covered, dry locations where the maximum moisture content will not exceed 16 percent, and it must not be used in applications where it will obtain a moisture content greater than that. Keep it wrapped during storage, protect it after install, and seal the ends and edges to resist moisture.

Can an LVL beam be cut, notched, or drilled on site? Cutting to length is fine. Beyond that, no — not without manufacturer approval. Except for cutting an LVL member to length during construction, cutting, drilling, or notching is outside the scope of the evaluation report.

How should LVL be stored to keep it straight? Keep it dry and supported. Even though it’s more dimensionally stable than solid wood, the product may warp if it is not properly stored. Covered, off the ground, on level supports.

What’s the difference between LVL and glulam for a beam? LVL carries heavier loads and longer spans; it supports heavier loads and longer spans than comparable glulam or dimension lumber products. Glulam runs cheaper and offers an architectural look for exposed beams — one common glulam product is 20% to 30% less expensive than LVL. Pick LVL for concealed, high-capacity work; glulam where the beam shows or the budget is the deciding factor.

Does LVL come with a warranty? Yes, when installed to spec. Boise Cascade BCI joist, Versa-Lam LVL, and AJS joist products carry a limited lifetime warranty for the expected life of the structure. Cutting or wetting the beam outside the manufacturer’s specifications is how you lose that protection.