Manufacturers Beyond Code
like Bill Robinson's assessment of building codes as "bare minimum"
and his likening the code to getting a D grade ("Weather Barriers
for Coastal Conditions," January/February 2008;
www.coastalcontractor.net). One of the places where I see some
improvements with the code is its deferral to product manufacturer
installation instructions.
Take, for instance, IRC 2006's R613 Exterior
Windows and Glass Doors. It states: "Windows shall be installed and
flashed in accordance with the manufacturer's written installation
instructions. Written installation instructions shall be provided
by the manufacturer for each window." This is pretty powerful when
you stop and think about it. Instead of trying to address the
umpteen different window styles and possible installation details
or coming up with a "one size fits all" solution that is typical of
a prescriptive code, the responsibility is placed on the installer
and the manufacturer. Many window manufacturers provide very good
installation instructions for their products. The instructions
usually comply with the AAMA guidelines / ASTM E-2112 and are
certainly easier to navigate.
In the past, many manufacturers of building products dropped the
ball when it came to providing thorough installation instructions.
Now I see more and more companies showing details of how their
products integrate with others for a complete "systems approach."
Going "Beyond Code," as Clayton DeKorne suggests in his editorial
(January/February 2008), can also involve manufacturers — not
only through the products they provide us but also through
well-drafted installation instructions and education programs to
support those products. Certainly, these instructions and training
have to go beyond how to nail it to the wall or roof; they have to
address how to integrate a given product with all the others to
which it's connected.
Mike Guertin
East Greenwich, R.I.
Connector Corrosion
Ted Cushman's article on corrosion ("Fasteners for Treated Wood,"
Soundings, January/February 2008; www.coastalcontractor.net) was
the best I've seen in a long time. Question: What is the sensible
fastener to use to frame vented attics near saltwater? Would HDG or
even bright nails suffice because such an attic would remain mostly
dry?
Charles Campbell
Campbell Housewrights
Athens, Ga.
Editor's note: According to Prentiss Douglas, a research engineer
with Simpson Strong-Tie, there has not been a lot of real-world
testing that tackles this exact issue. But Mr. Douglas did point to
one study done in Hawaii that examined corrosion on steel framing
in vented attics, where the framing was protected from the rain but
not from the salt air. The steel sections were G60 galvanized
— the minimum available (Simpson Strong-Tie has gone to a
minimum of G90) — and considerable corrosion occurred after
just a few months at the coastal sites. The inland sites saw less
visible corrosion over the same duration. The authors of the study
recommend increased galvanized thickness for framing members and
fasteners in vented attics, but the exact level will depend on the
specific site. After exploring this issue, my inclination would be
to use a G185 (such as Simpson Strong-Tie's ZMAX) or stainless
steel for connectors at the plate line of a vented attic on
beachfront property. For framing nails, and even truss plates, it's
less clear. But given this issue, and the potential for storm winds
blowing out the soffits and drenching homes (see "Securing
Soffits," January/February 2007, and "Understanding Water
Intrusion," Soundings, March/April 2008), an unvented attic seems
like the best way to go.