Originally posted at metalconstructionnews.com / By Chuck Haba and Nikki Mezic
Cold-formed steel framing (CFS) is a highly sustainable, green building solution. Through technological advances and processing changes, steel has drastically reduced its carbon footprint. CFS boasts a high level of recyclability, energy savings and greenhouse gas reductions.
Steel is the most recycled material on earth and is reclaimed more than all other materials combined. Steel can be continually recycled with no degradation in strength or performance indefinitely making CFS framing a great sustainable choice for most building projects. CFS contains a minimum of 25% recycled steel and is 100% recyclable.
Recycled steel has an impact on both energy consumption and greenhouse gas emissions. Steel production produces nearly no waste. It is currently enjoying a material efficiency of 97%. Material efficiency is a metric that measures how much raw materials are lost or wasted in the production of a material. Only 3% of the raw materials are lost in the production of steel. Also, since the 1980s, there has been a 21% reduction in the need for raw materials to make steel. This comes from research, technology improvements, and good planning.
The primary raw materials that go into steel production are iron ore, coking coal and recycled steel (scrap). Recycling steel production’s by-products results in reduced greenhouse gas emissions. For example, slag is the impurity that comes from iron production. Taking this slag and reusing it in the cement industry has reduced CO2 emissions by up to 50%. Slag is also used as a primary raw material in mineral wool insulation and certain ceiling tiles. The steel industry impressively reuses all its gas emissions.
Metal framing is recognized by various green building organizations such as LEED. Metal framing can qualify for up to six LEED points including points for environmental product declarations, sourcing of raw materials, construction and demolition waste management, and innovation.
Metal Versus Wood Framing
A common misconception is that wood is the greener building material option. When it comes to being green, CFS framing has multiple advantages over wood framing. Metal framing often has superior recyclability, a reduced carbon footprint, lower total project cost, greater convenience, increased stability, superior fire and pest resistance, plus greater strength, and longevity.
Steel can be recycled infinitely while wood has recyclable limitations. Typically, most steel construction scrap is sold back to be reclaimed while wood scrap largely ends up in a landfill leaving a larger carbon footprint. Metal is lighter than wood and takes up half the space of lumber because its hollow shape allows two studs or track to be nested together. This makes for easier and cheaper transporting and storage. Lighter gauge metal studs can be easily cut with handheld snips, or with a metal-cutting saw blade and a miter saw.
Steel framing is easier to handle because the studs typically weigh a third less than wood and can be installed at 24 inches on center. Also, they are attached with screws, so moving studs is simple if you make a mistake and need to reposition or change them.
Wood is prone to twisting and warping while metal is not. Wood also wicks moisture, which can lead to mold growth and rot, while metal is immune. Metal is prone to rust; thus, metal framing has stringent code requirements for galvanization and protective coatings. Wood burns, metal does not. Also, carpenter ants and termites can severely damage wood construction, but not metal.
The strength and ductility of structural CFS framing, along with the holding power of CFS connections, make it ideal for construction in high-wind and seismic zones. Metal’s strength-to-weight ratio is often significantly greater than that of wood.
CFS is a great choice for sustainable building due to virtually zero waste and 100% recyclability. It has one of the lowest carbon footprints of any building material available and is a superior building material to wood in most cases. With ongoing technological advances in CFS manufacturing practices, steel is poised to be the no.1 framing material in the world.