- Q.We are currently building a
steel-framed house near the ocean in California. Our
site is very close to the water, and I am concerned
about rust problems developing in the steel framing. We
have already noticed small surface rust spots on some
of the steel tracks on the floors. It seems as though
these rust spots are being caused by the small
particles of metal shavings left in the tracks either
from drilling through the studs or where they were
screwed together during assembly. I have also noticed
that rust is forming on the ends of cut studs. Will the
rust stop after the house is closed up, or will the
rust spots grow over the years?
A.Corresponding Editor Paul
Fisette responds: All structural steel studs
should be galvanized. When you build in a coastal
environment, you should specify a grade called
G-90. G-90 steel has a heavier zinc coating to
provide extra protection in hostile
environments.
Rust on a steel stud can be compared to rot on a
wood stud. When a wall is properly constructed,
there is little likelihood of a stud rusting to the
point of failure. But it is important to use proper
wall construction that shields the framing from
exterior elements and minimizes the chance of
condensation within the wall cavity.
Normal cutting and drilling of steel studs
removes the zinc coating in the cut area. However,
in most cases the coating adjacent to the cut will
"sacrifice" itself to protect the cut area. If you
are concerned about areas of extensive rust, such
areas can be cleaned with a wire brush, and then
sprayed or brushed with a zinc paint called ZRC
(ZRC Worldwide, 800/831-3275;
www.zrcworldwide.com). The zinc in ZRC is the same
material used to galvanize the studs. ZRC can be
purchased in a good paint or hardware store.