LVL: what laminated veneer lumber is in construction

LVL lumber sizes

LVL lumber sizes come from two numbers: a fixed ply thickness and a list of stock depths matched to framing members. Laminated veneer lumber is made in one thickness per ply, 1.75 in, so an LVL beam gets its width from how many plies are fastened together and its load capacity from its depth.

Depths are chosen to align with the joists and headers around them, which is why the list tracks common framing dimensions. Beams are commonly built as 2-ply or 3-ply members fastened together per the manufacturer table so the plies share load.

Depths and the 1.75 in ply thickness are the stock sizes named in the definition above; the built-up widths are simply ply thickness times ply count, and 2-ply and 3-ply are the common framing builds. Ply count and depth for any given beam come from the engineer or the manufacturer span table, not from this table. LVL must be installed with the wide face vertical when it acts as a beam.

LVL in construction: where it is used

In construction LVL shows up wherever a framing member has to carry more load, or span farther, than sawn lumber can. The common applications are flush and dropped beams, garage door headers, long-span window headers, ridge support, and rim board. Because the veneers run lengthwise and defects are dispersed through the billet, laminated veneer lumber is stronger and far more consistent than sawn lumber, with no crown to chase.

Each member is specified by an Fb bending value and an E modulus stamped or noted on it, and a beam has to be installed with its wide face vertical. Bearing length is called out at each end, commonly 1.5 to 3.5 in; insufficient bearing changes the support framing below.

LVL and glulam are not interchangeable. LVL is made from thin veneers all running lengthwise, comes in fixed thicknesses, and ships in handy plies, so it suits standard plied beams and headers hidden inside framing. Glulam is made from stacked dimensional lumber laminations in larger custom cross sections for longer spans and is available in appearance grades suitable for exposed work. LVL has visible veneer lines and an industrial look, so it is normally hidden in a wall or floor, or wrapped, rather than left exposed.

How LVL cost is measured

LVL cost is measured per linear foot at the specified depth, and priced per ply. That is why plies are counted separately: a 2-ply beam over a 16 ft opening is 32 linear feet of material at that depth, not 16. Quantities roll up as total linear feet by depth so each depth can carry its own rate.

The board foot is the other unit you will see on lumber quotes, since yards price commodity framing by volume. It is the general lumber volume unit rather than the working unit for engineered beams, so a laminated veneer lumber line item is normally carried in linear feet per ply and only converted if a supplier quotes by volume.

Three things drive LVL cost per linear foot. Depth is the first: a deeper section costs more per foot than a shallow one, so the rate is always tied to a depth. Ply count is the second, and it multiplies the footage directly, so moving a beam from 2-ply to 3-ply raises material by half again for the same opening. Span is the third, because it is what sets the depth and ply count in the first place, through the engineer or the manufacturer span table.

Two cost items sit outside the per-foot rate and are counted separately off the details: connection hardware such as hangers, plus the through-bolt or nail pattern joining the plies. Add a small length allowance so beams bear fully on their supports and can be trimmed clean, and confirm the called-out bearing length at each end, since that can change the support framing.