To Be or Not To Be - Light-Gauge Steel - That Is the Question
By Perry A. Tabor, P.E.
Our recent articles featured the integration of certain innovations, manufacturers' components and engineered panels. This month's article features another innovation: light-gauge steel (LGS), also known as cold-formed steel (CFS).
To best serve your industry, your clients and your community, it is incumbent upon you to familiarize yourself and your colleagues with various available building materials, construction methods and design approaches before you actually commence your design.
Being innovative, creative and efficient with your design can result in saving significant resources, as well as construction costs while still achieving a structurally sound project. Conversely, innovation under certain project conditions may not bring the results you expect to achieve.
One relatively recent innovation, over this past decade, has been the use of LGS in residential construction.
Often, we are asked, "Should I build in LGS or wood?" We believe that the answer lies in the project details. Here are just a few questions you may want to consider when evaluating whether to use LGS or wood for your residential project.
- Repetition: Are the floor plans being repeated over several floors (as with apartments and townhouses), or are there over 150 units comprised of five floor plans (as with production housing)?
- Project Scale: Is the project over 100,000 square feet total?
- Complexity: Are there any substantial plan articulations involved?
- Labor Force: Are there qualified trades to erect and to perform mechanical-electrical-plumbing trade services? Do the MPE trades recognize the economies available (e.g., pre-punched studs and floor joists)?
- Fire-Rating: Does code restrict the use of combustible assembly (e.g., wood framing with plywood assembly) in favor of non-combustible assembly (e.g., LGS assembly) with composite concrete deck?
- Economies: What is the current and forecasted price of lumber versus LGS materials? (Wood and LGS oscillate as competitive materials.)
- Site Constraints: Would prefabricated building assembly address site constraint conditions (e.g., lacking construction material staging area)?
- Maximized Floor Area: Is the wall assembly envelope required to remain consistent over several floors? (LGS can achieve substantial increased strength without increasing the material thickness before requiring increasing wall thickness.)
- Quality Control: Entire building assembly can be computer modeled prior to precision machine-cutting and labeling components within a production facility. Also, the material is resistant to shrinkage, twisting, cupping, splitting, warping, rotting and insect infiltration as is common with wood assembly.
Once you have addressed these preliminary questions, you should be able to make a more informed decision as to whether LGS or wood is the right choice for your project.
Our firm, TEAC Structural Engineering, has proactively supported and encouraged the advancement of LGS residential projects through industry education and advocacy, as well as by embracing its use in a large percentage of our production and attached housing, and with a small percentage of our custom homes. In so doing, we have become a respected leading authority in LGS projects.
Hopefully, you found our brief introduction to LGS to be informative. If you would like to see this topic covered in greater detail, please let us know. Otherwise, we look forward to covering other innovations and topics of interest in future articles.
September 2007 Builder Architect Edition Issue