Most contractors that frame residential
and light-commercial buildings
are now (or soon will be) using wood
I-joists. For builders accustomed to the
shape and heft of conventional sawn
lumber joists, the weight and appearance
of a typical wooden I-joist often
raises an immediate concern about its
ability to handle the load. How could
such a thin, lightweight material carry
as much as a sawn 2x10 or 2x12?
Situations like the one in the photo
above seem to defy common sense.
How can you possibly remove so much
of the I-joist web in the middle of a
span? Yet the hole chart for that particular
I-joist allows you to. Can you imagine
doing that with a sawn joist?