When used along with joint sealing tapes, flashing materials, and sealants, nearly all foam sheathings meet code requirements for use as continuous air barriers. 

Top Resources for using Foam Sheathing as an Air Barrier Material in an Air Barrier Assembly:


Tools & Education

The Air Barrier Association of America (ABAA), in conjunction with Oak Ridge National Laboratories (ORNL) and the National Institute of Science and Technology (NIST)  have created a web based energy saving calculator for building airtightness. The purpose of this free calculator is to quantify energy savings based on the use of air barriers and increasing the airtightness of buildings.

Best Practices

This guide from Building America addresses various means of applying foam sheathing on 2x4 wood framed walls in climate zones 3-5, including integration with other components (e.g., windows and cladding) for foam thicknesses up to 1-1/2”. It also addresses air barriers,  water vapor retarders, and use of foam sheathing as a WRB or in combination with a separate membrane WRB.

Practical Research

This project was to determine the most appropriate way of retrofitting old CMU constructed buildings from the inside. A short list of potential walls were modeled to determine energy savings. Two of the most promising walls were then constructed on the Building research Platform at Oakridge National Laboratories. They were instrumented and monitored. 

The purpose of this project was to increase the knowledgebase on air barriers for residential buildings. To this end, nine air barrier assemblies were evaluated following a modified version of ASTM E2357. The assemblies included the eight air barrier types that are readily available in the US (including one assembly using foam sheathing ci). 

Additional Information

A brief history of air barriers in buildings, from the days of interior polyethylene air barriers, all the way to the foam sheathing ci 3-in-1 solution. 

This guide is a resource for understanding the air leakage requirements in the 2012 IECC and suggestions on how these measures can be met. It also provides information from Building America’s Air Sealing Guide, best Practices and case studies on homes that are currently meeting the provisions.