Imagine the following scenario.

The drywall crew arrives at your construction site to begin work. The crew leader asks you how to screw their drywall through the two inches of foam insulation that someone has hung on the bottom chord of your trusses. Similarly, the siding crew is in panic over the fact that their screws are not long enough to go through a layer of foam insulation and structural sheathing before hitting a stud.

Sounds familiar? Such a scenario unfolds a chain of other events.

The structural engineer considered that the drywall was providing bracing to the bottom chords of trusses and wants the foam removed or other bracing installed. The code inspector says you need to prove that the whole assembly meets the newest energy code U-factor requirements. . Your superintendent is looking for window jamb extensions to fit with wider walls. As you navigate through such problems you are left wondering why these issues were not discussed during the early planning process.

This is just a sampling of issues that the steel framing industry will need to address as changes to energy codes begin to impact jobsites.

In September of this year, the International Code Council (ICC) - the group that oversees development and maintenance of the International Energy Conservation Code (IECC) and its counterpart for homes, the International Residential Code (IRC) – passed a series of code changes designed to make the energy requirements 30% more efficient than current requirements. For steel framing, this will typically mean more areas will require thicker amounts of foam insulation.

Future articles in Framework Online will address some of the structural and other changes that will be included in the 2009 codes. In this article, we provide you with some information on code changes that can help you mitigate the extra costs and issues often associated with foam insulation on your walls, roofs, and floors.

The Steel Framing Alliance in cooperation with the American Iron and Steel Institute was instrumental in gaining acceptance of two significant options for residential buildings that can reduce costs associated with foam insulation in wall assemblies in the 2009 IRC and IECC.

First, the ICC membership approved a code change that will allow less insulation than previously required for steel framed walls in Climate Zones 1 and 2. These zones are the southern-most US locations that include much of the current or potential market for steel-framed homes.

The ICC membership approved a reduction in the R-value of continuous (foam) insulation for walls in these zones – from R-5 to R-3. SFA and AISI provided the supporting data for the code change and testified for it at the hearings. This reduction will allow the use of half inch of XPS foam on walls as opposed to one inch, significantly reducing the cost and practical difficulties with a thicker wall assembly. This was one of the few proposals approved that reduced the insulation requirements.

Second, SFA was successful in gaining approval for an optional wall assembly. Instead of using both cavity and exterior foam insulation, the IRC and IECC will now allow just exterior insulation of R-10. No cavity insulation will be required if this option is selected for a steel framed wall.

These and other changes are the result of a codes and standards program SFA established in late 2007 to better influence the development of requirements that impact our industry. At the same time, we are working to develop resources that will further assist the industry in meeting and exceeding codes in a cost effective manner.

SFA recently published a new Thermal Design Guide that offers information useful across all climate zones on how to build energy-efficient buildings. The Guide includes a section that shows how to use the performance approach to comply with energy codes. The performance option is based on energy simulations. Before you cringe at the thought of buying another software package and consuming months of time training your staff, keep in mind that there are some very easy to use programs. Some like RESCheck, are available free from the U.S. Department of Energy at www.energycodes.gov/rescheck.

The benefit of the performance option is that it allows a designer to trade off insulation in one part of the home, or even take advantage of items like better windows to reduce insulation requirements elsewhere. So you may be able to reduce or eliminate costly exterior foam insulation by making it up elsewhere.

A downloadable copy of the Thermal Design Guide is available free of charge on the SFA website at www.steelframing.org. Look for Quick Links near the bottom third of our home page.

As we continue to make progress in the codes and standards arena, look for more information here in Framework Online in the months ahead.

Mark Nowak
President, Steel Framing Alliance