Having just attended the ICC 2018 Committee Action Hearings in Columbus, Ohio, last week, Vladimir Kochkin, Home Innovation’s director of building science, returned with great news – the code change he co-sponsored to improve coordination between energy code and building code requirements passed the first hurdle in the ICC code development process when it was approved by an ICC committee. The purpose of the change is to provide designers and builders with more options for buildings energy efficient and durable walls for compliance with existing energy codes and energy programs. The change was co-sponsored by Jay Crandell, representing the Foam Sheathing Committee of the American Chemistry Council.
"Because we are able to engage directly with builders constructing energy-efficient homes across the country with our Building America and other work,” Kochkin says, “we get first-hand knowledge of the types of solutions the industry is seeking as it transitions to the next generation of building codes and construction solutions. Then, we can apply our building science expertise to find the sweet spot – the most practical intersection of energy efficiency, durability, and ease of construction.”
The code change coordinates the requirements for continuous insulation with provision for Class II vapor retarder (e.g., Kraft paper). As a result, less foam sheathing can be required on the exterior surface of walls with continuous insulation while still ensuring good moisture performance of the wall assembly. This change will enable solutions that are more practical to build in the field – cladding and windows are easier to install with less foam sheathing required on the outside wall. The change will be most applicable to low-rise and mid-rise construction in Climate Zones 3 through 8, which comprise a large part of the country.
The change will allow builders to continue using Kraft paper – the tried-and-true longtime industry favorite – or take advantage of modern materials, such as responsive or “smart” vapor retarders. In this way, traditional 2x4 and 2x6 walls with Kraft paper vapor retarder and R-5 foam sheathing can deliver the required overall wall R-value required by the energy code with only minimal changes from conventional practices.
In addition to the Home Innovation team and the other co-sponsors, this code change was broadly supported at the hearings by a range of organizations and experts. But this is not the end of the road for the process. The change was approved by the ICC committee and now advances to the next step, wherein public comments will be solicited and accepted ahead of the second round of hearings later this year.
The code change proposal was informed by a multi-year research program Home Innovation conducted on energy-efficient wall systems. Learn more about the moisture research at Home Innovation by visiting www.homeinnovation.com/moisturestudies. You can also follow the next steps in the ICC Current Code Development Cycle online.
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