March/April 1997
While wood continues to be the framing material of choice in the residential housing market, the steel industry has launched an aggressive campaign that ambitiously seeks to claim 25 percent of the niche.
By Eileen Zagone
Eileen Zagone is an associate editor for Scrap.
No matter what your house is made of on the outside—brick, wood, stone, or stucco—chances are its frame is wood. After all, residential homes in this country have been built with wood frames since colonial times, and wood continues to be the overwhelming choice for residential framing.
But if the steel industry has its way, more and more new homes will have galvanized steel frames. Though well-entrenched in commercial construction since early this century, steel has ventured into the residential framing niche in only the past few years. Why now? Because certain conditions in the wood market made the niche ripe for invasion, and several high-profile and well-financed steel industry organizations joined together to promote the use of steel in this “new” application.
Since then, steel has steadily gained market share. And though it currently accounts for a small percentage of residential frames, the metal’s battle with wood has only just begun.
Opening the Door
Steel saw its chance to crack the residential housing market in the early 1990s, when strong overseas demand for domestic forest products and a tightened supply of timber caused lumber prices to rise and fluctuate wildly. Every aspect of the wood industry felt the pinch, and builders became frustrated by the price volatility as well as the uncertain supply of wood for residential framing. Notes Nader Elhajj, a researcher with the National Association of Home Builders’ (NAHB) research center (Upper Marlboro, Md.): “A builder has to have some feel for where the market is headed when he bids on a project, otherwise he’ll wind up losing money when the time comes to purchase building materials.”
And that’s exactly what happened, prompting a search for economical building alternatives. NAHB enlisted in this search and launched a research program to explore materials that could compete economically with wood in framing applications. Its three-year program—which has been funded by a variety of organizations, including the American Iron and Steel Institute (AISI) (Washington, D.C.), the Steel Recycling Institute (SRI) (Pittsburgh), and the Department of Housing and Urban Development (Washington, D.C.)—has determined that steel is the most viable contender for a share of the residential framing pie.
And the steel industry wants more than just a small slice of the pie. It wants 25 percent of the total U.S. residential housing market by 2000, according to Andrew Ziolaowski, AISI’s director of construction markets.
How realistic is that goal? As of 1995—the most recent year for which statistics are available—steel framing was used in about 55,000, or 5 percent, of the 1.1 million homes built, AISI estimates. While this may seem a far cry from 25 percent, steel’s share has been growing rapidly, from “at most a few hundred houses built with steel” in 1991 to 55,000 just four years later, Ziolaowski says. At this rate, he asserts, the 25-percent goal seems reachable by the turn of the century.
So how does the wood industry feel about this? “Despite all the hoopla over steel, wood is still the overwhelming framing choice in the majority of homes,” responds Butch Bernhardt, director of communications for the Western Wood Products Association (WWPA) (Portland, Ore.), an association representing wood producers in the 12 Western states. While he concedes that steel has claimed market share in the past few years, he asserts that these gains are relatively small and doubts that steel will reach its 25-percent goal in the foreseeable future.
The Bottom Line
In the battle between wood and steel, cost is and will be a significant factor, especially considering that it takes an average of 5 to 7 tons of steel and 8 to 9 tons of wood to frame a house.
One cost issue relates to price stability, which can have a significant effect on builders’ job estimates and, ultimately, their bottom line.
While steel prices have the reputation for being relatively stable, wood prices have been more volatile, with the price peaks of a few years ago serving as a reminder of the changes in timber supply that plague the wood industry. One of these changes has been the withdrawal of public land from use by wood producers, which has restricted lumber supplies and raised prices, Bernhardt notes. The key to price stability, WWPA says, lies in establishing predictable, sustainable timber supplies for mills, but that would require significant changes in land-use regulations.
Another cost issue is simply the buying price of wood and steel, and how that price affects the overall cost of a building project.
Unfortunately, no impartial study has compared the cost of wood framing with steel framing in a typical house, Elhajj says, though he notes that two studies on this issue—one conducted by the wood industry and one by the steel industry—came up with total costs within 5 percent of each other.
Studies aside, coming up with a cost formula would be next to impossible because there are a variety of factors that would have to go into such an equation, including not only the cost of the raw material but—in steel’s case—also the cost of builder training, specialized construction equipment, and more.
Still, on the cost issue, AISI maintains that “framers experienced with steel say it goes up quicker and cheaper than wood,” Ziolaowski says. He concedes, however, that there is certainly a learning curve associated with working with any new material and that builders inexperienced in working with steel may initially find it more expensive and time-consuming than wood framing.
Comfort in Familiarity
Without a doubt, one of wood’s greatest advantages over steel is its familiarity factor. As Bernhardt puts it, “Since wood framing is what has traditionally been used, builders are familiar with it and they find it easy to work with.”
Wood’s widespread use has also given it other advantages. For one, it enjoys an extensive and well-entrenched distribution network through lumber yards and home improvement centers—an infrastructure that steel framing products lack.
Another point, Bernhardt adds, is that the tools for working with wood are readily available, familiar, and inexpensive compared with some of the tools needed for assembling steel framing—tools that are frequently designed for commercial use and, therefore, often carry a hefty price tag, he claims.
Another drawback of working with steel framing, Bernhardt says, is the difficulty in distinguishing lighter-gauge non-load-bearing steel studs from the heavier-duty, yet similar-looking, load-bearing studs—something that’s not a problem with wood studs, which can be easily differentiated based on their dimensions. This identification problem can lead to the inadvertent use of the more expensive load-bearing studs for the non-load-bearing ones. The result for the builder, Bernhardt says, is that “there’s just too much guesswork with steel.”
While Elhajj agrees that this visual identification problem exists for steel framing, he notes that NAHB and its partners have been working with steel manufacturers to standardize steel framing products to mimic the standards in the lumber industry, such as designating and labeling steel studs as 2-by-4s or 2-by-6s depending on their intended use.
NAHB and its partners are also taking other steps to alleviate homebuilders’ anxiety about working with steel and improve the metal’s familiarity factor. For instance, the groups have created a national education program that includes a hotline for technical advice on framing with steel, as well as workshops in which engineers and builders assemble a house’s steel frame and learn the prescriptive methods that have been developed for framing with steel, says Ziolaowski.
There are also workshops geared toward educating building code officials about steel framing. Explains Elhajj: Until recently, builders who wanted to construct a steel-framed house had to hire an engineer—adding at least $2,000 to the total building costs—because building codes covered only wood frames. As of Jan. 1, however, the Council of American Building Officials accepted NAHB’s building codes for residential steel framing, and the association plans to expand the codes this year.
Not to be outdone, the wood products industry has stepped up its education efforts as well, offering training and retraining programs that reflect the changing scene in the timber industry.
Likewise, mills have made adjustments to cope with the waning supply of available timber. In short, they have developed technologies to “get as much as they can from what’s available,” says Bernhardt, pointing specifically to the growing number of engineered wood products made from what was formerly considered scrap wood. Far from being low-quality products, these composite materials can have greater structural integrity than solid wood products, observes one Washington, D.C.-area homebuilder.
While Bernhardt agrees that these products have some structural advantages over solid wood products, he notes that they may not necessarily spell cost savings since they require additional handling and manufacturing.
Physical Assets
When it comes to the physical advantages of using wood or steel in residential framing, Ziolaowski asserts that steel-framed homes “last longer and age better than wood-framed homes.” It’s common, he notes, for wood-framed homes to develop cracks, squeaky floors, and popping nails after about 10 years—problems that steel-framed structures won’t develop. “Therefore,” he states, “steel-framed houses have higher resale value.” In Bernhardt’s view, however, the long-term health of a house has everything to do with proper construction techniques and little with the chosen framing material.
Another of steel’s physical advantages is that it affords greater design freedom compared with wood, claim proponents. “Since steel is stronger than wood,” says Ziolaowski, “it can accommodate large open spans for a more open floor plan.” Also, adds Elhajj, steel studs create walls that are absolutely straight and offer easy formation of complex shapes. To create an interior arch, for example, a non-load-bearing steel stud can be easily bent into shape.
Steel’s strength also means builders can use fewer studs, supporters say. With wood, studs are generally placed 16 inches apart, but steel studs can reportedly be safely placed 24 inches apart.
Bernhardt counters that this spacing issue could present structural problems, noting that “if a portion of a large span fails, there’s no other adequate support to compensate for the failure.” With wood framing, he explains, there are “built-in structural redundancies” so that if one piece fails, there are additional connection points that can take the stress of a structural weakness.
When considering structural integrity, it’s also important to weigh which framing material is the most likely to withstand natural disasters such as earthquakes and hurricane winds. While wood framing can be used in potential disaster areas, it has to be so thick and builders have to use so much of it that to do so is cost-prohibitive, Ziolaowski says, asserting that “no framing material can withstand seismic forces and hurricane-force winds better than steel.”
According to Bernhardt, however, “the material used is not the deciding factor. It’s the design of the house that determines its structural integrity under extreme conditions.” In fact, he says, connections are the key to building a house that can withstand seismic and wind forces, and since wood framing uses more structural members than steel, it offers more protection—as long as the house is designed properly.
Termites are a slower but no less destructive force that can affect a house’s structural integrity. While steel is undeniably termite-proof, it’s important to note that not all wood-framed houses are susceptible to the pests. “Proper construction and maintenance are the keys to termite prevention,” Bernhardt states. Also, since termites reportedly find drywall appetizing, any house—steel- or wood-framed—still faces potential damage from the creatures.
Another important difference between wood and steel is how and how much each responds to temperature. It’s a fact that steel conducts temperature more effectively and readily than wood, which means a metal frame transmits cold and heat into and out of a house more freely than wood—with potentially significant cost repercussions for the owner.
One way to minimize steel’s conductive properties is to install insulation on the exterior framing, Ziolaowski says. NAHB, in fact, has developed a color-coded thermal design guide based on climate regions to help determine how much insulation is necessary for steel-framed homes.
Some builders, meanwhile, are addressing this problem by using wood on the exterior framing and steel for interior framing, says Elhajj, and the resulting combination-frame house reportedly requires no more insulation than a totally wood-framed house.
The Green Question
When weighing the merits of wood and steel, there’s also the inevitable environmental question of which is the “greener” building choice.
In Bernhardt’s view, wood has the edge in that it is “a renewable resource, and the timber being cut today is coming from managed forests.” The timber industry, he notes, plants more than 2 billion trees a year, and WWPA estimates that current timber growth exceeds harvest by 30 percent.
Conversely, he asserts, “making steel involves tremendous amounts of energy—more than wood—plus there’s considerable environmental impact from mining the raw material.”
Though it does take more energy to produce steel for framing than to mill wood for framing, “there’s more to this issue than just the production cost of wood versus steel,” Ziolaowski says, pointing to the issues of “deforestation, poorly managed forests, soil erosion, and more that are tied to the timber industry. If you look at the whole picture, wood comes out the loser.”
And then there’s the issue of recycling.
On building sites, the fact is that scrap steel is usually recycled, whereas scrap wood tends to be discarded. One reason for this is that steel is an eminently recyclable material that can be melted and remelted time and time again without degradation. Also, there’s a well-established collection and consumption infrastructure for steel scrap that creates financial incentives to recycle it. Scrap wood, on the other hand, may have some reuse and recycling options, but it has nowhere near the recycling advantages of steel.
And there’s another recycling-related point that bears noting: If steel framing catches on in a big way, there would be increased demand for steel scrap, which could boost the recovery of obsolete steel scrap even higher. This would be especially true if minimills—which are exclusively scrap-fed—enter the steel-framing niche. At the moment, however, most of the steel used in residential framing is produced by integrated mills, which use only about 30 percent scrap in their metal mix, notes Ziolaowski.
The Writing on the Wall
While wood and steel are certainly the two main contenders in the residential framing bout, a few other materials are attempting to climb into the ring.
Some building methods, for instance, use foam similar to that used in coolers in combination with concrete to form termite-resistant load- and non-load-bearing walls. In one application, lightweight foam is sandwiched between two sheets of welded steel mesh and then coated with concrete to create a stucco-like effect that offers structural integrity, good insulation, and sound-proofing. Another method involves building a structure out of stacked hollow foam blocks, then filling the blocks with concrete for added stability.
Aluminum has also been used by some builders, though its cost is prohibitive for widespread use and the aluminum industry is reportedly not aggressively targeting the structural framing market.
For now, therefore, the framing contest boils down to wood and steel, and only time will tell if steel will steal the coveted 25-percent of the market from the long-time leader. About the only certainty is that both materials are in this contest for the long haul.
As Elhajj notes, “There’s a lot of enthusiasm and momentum for steel framing now,” and, perhaps most importantly, the steel industry has “committed itself and the money” needed to make sure the metal has a fighting chance to reach its 25-percent market share goal.
The wood industry, meanwhile, “isn’t afraid of the competition,” says Bernhardt, stating confidently, “Wood is still the material of choice, and when the price of wood levels out, the allure of steel dissipates because steel can no longer compete.”
One house builder, however, almost shamefully concedes that he expects to use more steel in the future, though he admits that he “likes to knock on a wall and hear the familiar thud of wood rather than the clank of steel.”
Still, he adds, “I can also see the writing on the wall. Steel will continue to grow in this application, especially if the price of wood continues to fluctuate.” •
While wood continues to be the framing material of choice in the residential housing market, the steel industry has launched an aggressive campaign that ambitiously seeks to claim 25 percent of the niche.