Stl-Wood

Comparing Steel & Wood Framing

Issue of Concern Arguments for Steel Arguments for Wood Env.Bldg.News Analysis

Dimensional properties and stability Steel is far superior to wood--no shrinkage, exact dimensions. Builders are used to the movement of wood, can use manufactured wood products for greater stability. As framing lumber comes from younger and faster-growing trees, this is an important advantage of steel.

Pricing Volatile wood prices make steel more predictable, lower cost in some areas. Lumber prices dropping, even at their peak were no higher in real dollars than in 1970s. Thinner gauge steel for non-load-bearing walls is cheap, efficient, a good deal.

Thermal efficiency It's an issue but it can be resolved by adding exterior insulation or other modifications. Wood is naturally low in conductivity, insulates well. The number 1 problem with steel, this has to be addressed without adding too much cost or environmental impact.

Earthquake performance Steel is better: engineered performance, lighter weight of structure reduces damage. Wood is better because "structural redundancies" (overbuilding) add up to increased safety. No position. Leave it to the experts.

Fire performance Steel doesn't burn. Steel structures are safer. Steel loses its strength quickly at high temperatures. Wood protected by drywall is safer. No position. Leave it to the experts.

Insect resistance Steel is not attractive to insects; wood is. Preservative-treated wood is safe, effective. Borate preservatives are safe. It's probably better to use steel than frame with wood treated with arsenical preservatives.

Indoor air quality Steel is inert; wood releases terpenes and treated wood contains toxins. Untreated wood causes no problem for most people. Avoiding soil treatments with termiticides is the biggest IAQ benefit of steel. Otherwise both are relatively safe.

Timber resource availability and extraction Forest are being overlogged and destroyed. Builders need to stop using timber. Wood is renewable: nationwide new growth exceeds amounts harvested; forestry practices are improving. Widely variable by region, forest, and company/agency managing. We should strive for true multi-use ecosystem management in most areas.

Steel resource availability and extraction All raw materials used to make steel framing are in plentiful supply. Mining practices have improved dramatically. Much new steel is made from scrap. Mining causes total disruption of the affected area, and has caused severe water pollution from run-off. Recycled content of light-gauge steel is much less than most other steel. Mining impacts are significant, but raw materials are plentiful.

Lumber manufacturing Significant fuel use for kiln-drying. Preservative-treating industry deals with high-level toxins. Milling lumber is a very low-energy, simple process with minimal emissions or other pollution. Except for treated wood, concerns are minor. Big advantage for wood use.

Steel manufacturing Industry has invested $10 billion in environmental and efficiency improvements in last decade. Energy use and pollution are way down. High recycling rate means some environmental costs are spread out. Steel is one of the most energy-intensive industrial materials, generating pollution and waste from all stages of the process, including coking coal, purifying iron, and galvanizing. In spite of improvements, environmental impacts are still significant.

End-of-use recycling or disposal Steel is easily separated by magnet. There is always a market for scrap; contamination is not an issue. Wood is biodegradable, may be salvaged and reused. Markets for recycled waste wood from construction are growing. Big advantage for steel. Another reason not to use wood treated with toxins, as it won't biodegrade, may have to be handled as hazardous waste.

Issue of Concern	Arguments for Steel	Arguments for Wood	Env.Bldg.News Analysis
Dimensional properties and stability	Steel is far superior to wood--no shrinkage, exact dimensions.	Builders are used to the movement of wood, can use manufactured wood products for greater stability.	As framing lumber comes from younger and faster-growing trees, this is an important advantage of steel.
Pricing	Volatile wood prices make steel more predictable, lower cost in some areas.	Lumber prices dropping, even at their peak were no higher in real dollars than in 1970s.	Thinner gauge steel for non-load-bearing walls is cheap, efficient, a good deal.
Thermal efficiency	It's an issue but it can be resolved by adding exterior insulation or other modifications.	Wood is naturally low in conductivity, insulates well.	The number 1 problem with steel, this has to be addressed without adding too much cost or environmental impact.
Earthquake performance	Steel is better: engineered performance, lighter weight of structure reduces damage.	Wood is better because "structural redundancies" (overbuilding) add up to increased safety.	No position. Leave it to the experts.
Fire performance	Steel doesn't burn. Steel structures are safer.	Steel loses its strength quickly at high temperatures. Wood protected by drywall is safer.	No position. Leave it to the experts.
Insect resistance	Steel is not attractive to insects; wood is.	Preservative-treated wood is safe, effective.	Borate preservatives are safe. It's probably better to use steel than frame with wood treated with arsenical preservatives.
Indoor air quality	Steel is inert; wood releases terpenes and treated wood contains toxins.	Untreated wood causes no problem for most people.	Avoiding soil treatments with termiticides is the biggest IAQ benefit of steel. Otherwise both are relatively safe.
Timber resource availability and extraction	Forest are being overlogged and destroyed. Builders need to stop using timber.	Wood is renewable: nationwide new growth exceeds amounts harvested; forestry practices are improving.	Widely variable by region, forest, and company/agency managing. We should strive for true multi-use ecosystem management in most areas.
Steel resource availability and extraction	All raw materials used to make steel framing are in plentiful supply. Mining practices have improved dramatically. Much new steel is made from scrap.	Mining causes total disruption of the affected area, and has caused severe water pollution from run-off.	Recycled content of light-gauge steel is much less than most other steel. Mining impacts are significant, but raw materials are plentiful.
Lumber manufacturing	Significant fuel use for kiln-drying. Preservative-treating industry deals with high-level toxins.	Milling lumber is a very low-energy, simple process with minimal emissions or other pollution.	Except for treated wood, concerns are minor. Big advantage for wood use.

Steel manufacturing	Industry has invested $10 billion in environmental and efficiency improvements in last decade. Energy use and pollution are way down. High recycling rate means some environmental costs are spread out.	Steel is one of the most energy-intensive industrial materials, generating pollution and waste from all stages of the process, including coking coal, purifying iron, and galvanizing.	In spite of improvements, environmental impacts are still significant.
End-of-use recycling or disposal	Steel is easily separated by magnet. There is always a market for scrap; contamination is not an issue.	Wood is biodegradable, may be salvaged and reused. Markets for recycled waste wood from construction are growing.	Big advantage for steel. Another reason not to use wood treated with toxins, as it won't biodegrade, may have to be handled as hazardous waste.