laminated veneer lumber (lvl)

[massmanute]

I am wondering about laminated veneer lumber (LVL) for structural members.

Depending on the grade of LVL chosen, the modulus of elasticity for LVL products can be as high as 2E6, which exceeds the modulus of elasticity for Sitka spruce or Douglas fir.

However, density of LVL grades with modulus of elasticity of 2E6 is typically higher (e.g. about 40 lb per cubic foot vs. about 27 for Sitka spruce or 32 for Douglas fir) which is a negative factor. It's slightly lighter than white ash on average, with a higher modulus of elasticity than white ash, and I understand that white ash is considered a decent aircraft wood, though perhaps a bit on the heavy side. A grade of LVL with modulus of elasticity of 1.7E6 is lighter (about 36 lb per cubic feet).

I don't know how LVL compares in modulus of rupture, shock resistance, and other structural parameters.

Vendors of LVL claim less variability in structural parameters than natural wood, which is a good thing. Vendors claim that the veneers are graded (by various automated means) before the laminated products are built up, which is probably also a good thing, and because a slight weakness or defect in any single lamination has relatively little effect on the overall structure, that is also a good thing.

LVL tends to be expensive compared to regular lumber, but I will bet it is not expensive compared to aircraft grade lumber.

According to some historical notes, LVL was actually used in World War II to build aircraft, especially the Mosquito bomber, although it is likely that the LVL used then is not the same as LVL used in the building trades today.

There would be a number of things to consider of course, (more than can be discussed in an introductory post on the topic), but I thought it might be a good topic to discuss, particularly since I can't find anything on the topic in searches of this forum.