I just read an article by Ted
Cushman about the use of hardware with ACQ wood in coastal
areas (Soundings, March/April 2008). I have a question about
use of copper nails in ACQ wood: There is a project going on at
one of our sites where copper flashing is being applied to
roofing built of ACQ-treated wood. We are in a coastal
environment — the site is an old fort structure
alongside the Savannah River, 15 to 20 miles from its outlet to
the Atlantic Ocean. The question is whether it is better to use
copper or stainless steel nails. There is no doubt that copper
nails to copper flashing is best. I spoke with Nature
Wood/Osmose, the provider of the ACQ treatment on much of the
wood we order, and I was told that copper nails would actually
be better than the stainless. But a local carpenter had
reservations about using copper nails in the ACQ, based on
hearsay that the wood eats away at the copper. My understanding
of copper is that it is pretty stable for long periods in most
environments. What (if any) are the issues with copper nails in
wood versus use of stainless? And which fasteners would be best
to secure copper flashing to treated wood in our
Coastal Heritage Society
Ted Cushman responds: The corrosion issue
associated with ACQ in contact with metals is caused by
galvanic reaction — an electrical interaction between
dissimilar metals in an electrolyte (electrically conductive)
solution. In your case (as in an coastal environment), we have
the electrolyte solution — salt-laden water —
but we don't have dissimilar metals. Instead, we have just one
metal: copper. So based on the science, you should not see any
problem when you place copper flashing and copper nails in
contact with wood containing a copper-based treating solution.
That is consistent with your wood treatment supplier's
recommendation in favor of copper fasteners.
For more about the fastener selection, we turned to Roelif
Loveland, president of Maze Nails (www.mazenails.com). Maze
makes hot-dipped galvanized nails, stainless steel nails, and
copper nails. As Loveland pointed out, all three types of nails
are code-approved for use with ACQ. IRC Section R319.3 says,
"Fasteners for pressure-preservative treated wood shall be of
hot-dipped galvanized steel, stainless steel, silicon bronze or
Copper nails and copper flashing in ACQ lumber is an unusual
enough application that it doesn't have much of a track record.
So it may not deserve a hard-and-fast guarantee. But it does
comply with code, and based on the information that is
available out there, it seems like a pretty safe
How Small Is Small?
"Storm-Water Regs Grow Up"
(Soundings, May/June 2008) states: "Any construction project
that disturbs even a half-acre of land surface falls under the
requirements of the U.S. Environmental Protection Agency's
National Pollutant Discharge Elimination System (NPDES), which
requires you to file a federal or state permit application and
implement an approved SWPPP." When or is this in effect?
Malcolm T. Martin
Managed Response, Inc.
Clayton DeKorne responds:
The NPDES Phase
II stormwater was signed into law in December 1999 and requires
stormwater permitting on "small construction sites" (commonly
called Phase II sites). However, we misstated the exact
definition of a small site. The current EPA ruling defines
small construction activity as any land disturbance on sites
equal to or greater than 1 and less than 5 acres. (The Phase I
ruling covers sites greater than 5 acres.) Site activities
disturbing less than 1 acre are also regulated as small
construction activity if they are "part of a larger common plan
of development or sale with a planned disturbance equal to or
greater than 1 acre."
At this time, only one state regulates individual sites less
than one acre: South Carolina requires stormwater permits in
coastal counties when the disturbance of more than half an acre
lies within half a mile of a receiving waterbody (a lake,
river, or ocean).