Ask the Architect

More on steel beams

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Q. We read your column about steel beams in a crawl space (indoors), and wonder about our house, which was lifted and put on columns with steel beams underneath, holding everything up. We live several blocks from the ocean, and the beams are visible and exposed. They haven’t been painted, and are a rust color. Is this a problem? Can they be galvanized, or should they be painted, or are they OK the way they are? Our contractor says they have a paint coating, but we already see rust spots. Our plans say “rust-preventive paint.” Is that what was done, and is it enough?

A. Your situation is of great concern and, no, it’s not OK if the beams weren’t correctly painted or galvanized. Rust-preventive paint is a dark shade of red, usually. The next time you drive under one of the 2,000 bridges in New York City, make note of the fact that all the exposed steel beams you see are coated with sophisticated paints that have undergone the most rigorous testing in the industry. The colors vary from blue to gray or green. Bridge painters work full time, starting at one end and repainting the main bridges, then starting over when they reach the other end, because it’s that important to protect the exposed steel. For the bridge painters, it’s a full-time job.

I’ve run the gamut with contractors over the years, from those who are careful and concerned to those who dismiss the vulnerability of the materials they handle. There’s a reason for careful, knowledgeable selection of materials for the particular application. My previous column addressed steel in controlled indoor spaces. Structural steel, which is constantly exposed to open weather and windborne salt particles, has to be protected. Even specially formulated steel, with a rust veneer oxidized finish, is manufactured that way, and costs more.

When the structural framing has been altered, substituted or reconfigured during construction from what is shown in the plans, it shows a blatant disregard for the designated responsible professional’s decision. What is worse is that until structural collapse occurs, the owner or building official often casually accepts the contractor’s deviation, without holding the constructor responsible for ignoring approved plans. Between the calculations for how loads will transfer through the building to the selection of materials, design decisions are not arbitrary, and are not to be randomly substituted.

If the plans for your home did not address a specific coating of the steel, it doesn’t mean none is needed. I was recently questioned by a contractor about galvanizing the steel, at greater cost, rather than just using rust-preventive paint, and I was appreciative for the discussion. The outcome was that the owner accepted the choice and extra cost, to be more cautious. You don’t get a second chance to galvanize the steel once the structure is assembled. Use rust-preventive paint if you’re not sure what was done.

© 2017 Monte Leeper. Readers are encouraged to send questions to yourhousedr@aol.com, with “Herald question” in the subject line, or to Herald Homes, 2 Endo Blvd., Garden City, NY 11530, Attn: Monte Leeper, architect.