A.David Utterback
responds: The short answer is yes, you want to
have a nail in every hole. It’s the shear
and the withdrawl resistance of the nails that
carry the structural load, and joist hangers are
sized with a specific number of holes to carry
specific load ranges. Typically, wider dimension
members carry heavier loads, so deeper joist
hangers have more holes in them for more nails.
Just as important is using the right type of
nail. I can’t count the number of houses
I’ve been to that have box nails, 8d
galvanized nails, even roofing nails, instead of
the common nails recommended by the manufacturer
and required by code.
All hanger manufacturers have specific nail
recommendations. Typically, the least you can use
for a single joist hanger is a 10d common. The
short joist hanger nails are also 10d nails, and
they can be used for single joist hangers.
When it comes to double joist hangers and beam
hangers, however, you need a full-length 16d common
nail. When you’re hanging a beam, you
won’t be hanging off a single member, so
you don’t have to worry about a
full-length nail sticking out one side.
Don’t use box nails or roofing nails,
and don’t substitute 16d sinkers for 16d
commons. You can use 16d sinkers only in
place of 10d commons.
David Utterback, of the Western Wood
Products Association, provides technical
information and gives building code seminars
throughout the country.