Eight dollars. $8. However you write
it, that small sum can make a huge difference in the survival of
homes exposed to high winds.
What does $8 buy? That's the estimated cost of switching to 8d
ring-shank nails from 8d smooth-shank nails for a typical
Literally hundreds of sheathing panels have been tested by the
International Hurricane Research Center (IHRC) at Florida
International University and at Clemson University, where I was a
professor of civil engineering until 2004.
The data included individual nail withdrawal values as well as
panel tests in vacuum chambers. Interestingly, we found single
fastener ultimate withdrawal capacities for smooth-shank nails are
often substantially lower than those implied by the National
Design Specification for Wood Construction (NDS), while
capacities for various ring-shank nails used in the test were
generally equal to or greater than those implied by the NDS.
Head pull-through failures can also contribute to or control the
ultimate uplift capacity of roof panel connections. This failure is
commonly observed when ring-shank nails or screws were used to
attach nominal 1/2-inch plywood and oriented strand board
However, these panel tests found head pull-through failures were
extremely rare for 5/8-inch (actual 19/32 inch) sheathing, even
when ring-shank nails were used, supporting the suggestion that
this thickness is a good choice in high-wind areas.
Through this research, we can conclusively say that 8d ring-shank
nails installed at 6-inch spacing over the entire roof nearly
doubles the uplift capacity of 5/8-inch roof sheathing compared
with panels attached with 8d common bright or 8d galvanized
Stronger nails, properly spaced in 5/8-inch sheathing. Increasing
the wind resistance of homes along the coastline and across the
country does not require a significant investment. — Tim
Dr. Tim Reinhold is vice president of engineering at the Institute
for Business & Home Safety, a national nonprofit initiative of
the insurance industry dedicated to reducing the damages and
suffering caused by natural disasters.