Now that I?m just
relaxing (just waiting for USC to show OU exactly what an ?average? offense is
like), I thought I would throw out a question to find out how others do
Currently, I detail
straps to be installed over the plywood (oops, Wood Structural Panel)
sheathing. Otherwise, it would be difficult to install the SW edge nailing.
Simpson has load tested this condition and they believe it is O.K. to install
it like this. I know there may be some who don?t like this installation, but
for the purposes of this topic, let?s assume it?s O.K.
For CS straps, which
are 1-1/4? wide, a single 2X stud may be adequate for anchorage. Similarly,
for CMST straps which are 3? wide, double 2X studs would be a mimumum and may
be adequate for anchorage (both for tension and compression). Let?s assume
that they are for the purposes of this topic. With this scenario, how do you
address the stud which has the shear wall edge nailing as well as the strap
nails? I?ve heard where some folks omit the edge nailing at the strap. For
short straps, this doesn?t seem to be much of a problem. A CS16 has an end
length of 11? with 10d nails and 14? with 8d nails. However, with a CMST12,
the strap is more than half the height of the shear wall. I?m having trouble
reconciling forces with a FBD (load transfers from the SW into the end post
back through the SW into the strap).
Of course, one could
make the end post wider to allow the edge nailing to run past the strap. For a
CS, that would require a double stud. For a CMST, that would require 3-2Xs. I
don?t have so much of a problem with the larger strap (of course, all of the
multiple studs would have to be face nailed to transfer the load from the edge
nailing to the hold down strap), but it seems to me that this *might* be ?overkill? for a lightly loaded
CS strap. After all, CS20, CS18 and CS16 straps have capacities of 1,030 lbs,
1,370 lbs and 1,705 lbs respectively.
Opinions and comments