Healthy Home Basics - Framing and Insulation

30. We’re considering building a house with steel framing. Does it have any particular advantages?

Light-weight steel framing is becoming popular with some builders. It consists of C-shaped studs and channels that are usually lighter-in-weight than wood. Everything is held together with self-tapping screws, and the studs typically have holes prepunched in them for electrical wires and plumbing lines. This saves drilling time, but the holes have sharp edges, so they must be fitted with plastic grommets to prevent plastic-jacketed wiring from getting nicked and shorting out. Steel framing is also very uniform in size, it has no knots, and it won’t warp.

The biggest health-related advantage to steel is the fact that it never needs to be treated for termites. So, where toxic chemical use is the norm, or where less-toxic alternative treatments aren’t feasible, steel is a great option.

Although it’s not a concern for most people, some very sensitive individuals are bothered by the natural odor of wood, and steel is odor-free. Most framing lumber is pine or another softwood, and the odor is composed of the same chemicals in turpentine. These sensitive people are just reacting to much lower levels of the same pollutants that have the potential to bother all of us.

While steel itself usually doesn’t have an odor, it sometimes has a slightly odorous oil film on it left over from the manufacturing process that some sensitive people have had to wash off. A solution of water and TSP (tri-sodium phosphate, a heavy-duty cleaner often available in hardware stores) usually works well.

31. Are there any disadvantages to using steel framing?

The biggest disadvantage to building with steel has to do with the fact that steel is an excellent conductor of heat. An insulated steel-framed wall can be very energy inefficient. For example, there can be so much heat loss through steel studs, that the average insulating ability of the wall is degraded by up to 50%. This can be a serious drawback—especially in harsh climates—but there are some ways to minimize energy losses. For example, you can space the studs further apart. Fewer studs equals less heat loss.

Most residential builders have never worked with steel, so they don’t really understand some of the unique details that go into a steel-framed house. While the actual cost of the material is often comparable to wood framing, if a contractor is unfamiliar with steel, he may charge more for labor.

There are a few specialized tools required—a screw gun, a cut-off saw fitted with a steel-cutting blade, some tin snips, and perhaps a crimping tool. Plus, you’ll need a selection of self-tapping screws—they come in dozens of sizes and shapes.

32. Does it matte...