- 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.
