LVL, PSL and LSL come in a variety of sizes, some of which overlap. LVL commonly measures 1-3/4 in. thick, 3-1/2 in. to 18 3/4 in. deep and up to 60 ft. long, though thinner
and thicker stock can be ordered from some companies. It's normally used for beams, headers, hip and valley rafters, scaffold planks, wood I-joist flanges and rim board for wood I-joist closure.
PSL is used for posts, beams and headers. Beams and headers are 1-3/4 in. to 7 in. thick, 9-1/4 in. to 18 in. deep and up to 60 ft. long. Posts range
from 3-1/2 in. sq. to 7 in. sq.
LSL is used for posts, beams, headers, studs and rim board.It's also used for roof trusses, as core stock for windows and doors, and as flange stock
for wood I-joists. The posts, headers and beams are 3-1/2 in. thick, 3-1/2 in. to 16 in. deep and up to 48 ft. long. The studs are 1-1/2 in. thick, and the rim board
is 7/8 in. to 1-1/2 in. thick.
Other factors also come into play. To eliminate the need for a crane, some builders routinely fabricate big beams in place by sistering 1-3/4-in. thick LVL
or PSL sections (whichever type is stocked locally). PSL and LSL resist moisture-induced warpage better than LVL, which can make them the best choice where beams will be exposed to
wet weather during construction.