Over 53 Million Sq. Ft. of Waterproofing, Air and Vapor Barriers Installed
February 27, 2013
DOW STYROFOAM™ Brand Insulation Board (ESR-2142): NO THERMAL BARRIER OR IGNITION BARRIER REQUIRED UP TO MAXIMUM NOMINAL THICKNESS OF 2 INCHES
The purpose of this letter is to clarify that ASTM C578 Type IV and ASTM C578 Type X Dow STYROFOAM™ Brand Insulation boards with a maximum nominal thickness of 2 inches may be installed as an interior finish on the walls and/or ceiling without a thermal barrier or ignition barrier in any type of structure, including attics and crawl spaces (as recognized in Section 188.8.131.52 of ESR-2142) and residential basements (as recognized in Section 4.2.2 of ESR-2142).
ASTM C578 Type IV and ASTM C578 Type X Dow STYROFOAM™ Brand Insulation boards with a maximum nominal thickness of 2 inches have been tested in accordance with NFPA 286 and 2012 IBC Section 2603.10, 2009 IBC Section 2603.9 and IRC Section R316.6.
While these applications are identified and recognized under ESR-2142 (dated 10/1/12) Sections 2.0 and 4.2.2, it has been brought to The Dow Chemical Company’s attention that the placement of basements under Section 4.2.2 titled “Other Structures” has caused some confusion amongst Building Code Officials.
Dow is working with ICC-ES to revise the verbiage in ESR-2142 regarding the use of unprotected foam in residential basements to more clearly state that boards with a maximum nominal thickness of 2 inches may be installed as an interior finish on the walls and/or ceiling without a thermal barrier or ignition barrier.
In the interim, please feel free to directly contact Steve Thorsell, Manager of Environmental Programs, Ken Roberts, Senior Evaluation Specialist or Chris Allen, Senior Staff Engineer at ICC-ES with any inquires not sufficiently addressed in this letter.
Steve Thorsell can be contacted at 800-423-6587 ext. 4313 or firstname.lastname@example.org. Ken Roberts can be reached at 800-423-6587 ext. 5694 or email@example.com. Chris Allen can be contacted at 800-423-6587 ext. 3223 or firstname.lastname@example.org.
The Dow Chemical Company
Dow Building Solutions
Interior Foundation Insulation