Ask any builder who has used parallel-chord
floor trusses how he likes them and you're likely
to get an enthusiastic answer. No wonder. As
building components go, they have a lot going
for them. A floor truss can span 38 feet with no
intermediate support. It does this not with massive
timbers, but with a series of cleverly
arranged 2x4s. The use of smaller-dimension
lumber to shoulder large loads means that a
trussed floor makes more efficient use of wood
than a floor framed with 2x8s or 2x10s.
A truss makes better use of labor, too. There's
no cutting, so the framing goes faster; duct runs
can be built into the webs, speeding