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:

Tools & Education

Continuous Insulation: Research, Applications, and Resources for Walls, Roofs, and Foundations

Continuous insulation is used on foundations, exterior walls, and roofs and provides maximum thermal performance by minimizing thermal bridging. Continuous insulation products also can provide multiple functions including thermal insulation, water-resistive barrier, and air barrier. This presentation addresses these topics and more based on a comprehensive body of building science knowledge resulting in recent building code and energy code advancements.

ABAA/ORNL/NIST Energy Savings Calculator

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.

Durability by Design: A Professional’s Guide to Durable Home Design

In this updated guide, HUD is offering new and refined guidance for designing durable homes for today’s housing industry—addressing critical topics, including water vapor management, envelope design, and natural hazards. Building more durable homes also means providing more comfortable, affordable, efficient, and sustainable homes for America’s families.

Best Practices

Construction Guide: Next Generation High Performance Walls

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

Air Barrier Association of America - Evaluation of Air Barriers for Residential Buildings

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). 

Air Barrier Association of America - Wall Retrofit Project

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. 

Additional Information

Building Energy Code Resource Guide: Air Leakage Guide

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.

Forty Years of Air Barriers—The Evolution of the Residential Air Barrier

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.