Why choose spray foam insulation as an effective air barrier component
Icynene's codes and standards specialist, Peter Birkbeck, was recently invited by trade publication - Construction Canada - to provide an insight into how spray foam insulation, can help architects and builders meet air barrier requirements set forth in the National Building Code of Canada and the National Energy Code of Canada. Throughout the article, Peter discusses the benefits of an air barrier system, how spray foam insulation can be considered as a major component of an air barrier system, air barrier system evaluations, durability, installation considerations and how spray foam insulation is applied.
An air barrier system consists of building assemblies composed of continuously joined components. The function of the system is to provide control of air leakage into and out of the building enclosure. The use of spray foam insulation as an air barrier system in low-rise exterior walls can result in durable, high-performance building enclosures. The spray foam component functions as the exterior thermal, vapor, and moisture control layer. The seamless, self-supporting, monolithic nature of spray foam insulation can contribute to achieving air barrier continuity, especially with building exteriors with complex shapes.
Below is an excerpt of the article:
With varying degrees of detail and prescription, Canadian building codes—regardless of the model code—require all buildings to be provided with an air barrier. Where the language is more performance-oriented, such as in Part 5 of the National Building Code of Canada (NBC) and Part 3 of the National Energy Code of Canada for Buildings (NECB), key concepts such as “system” and “continuity” are introduced as well as quantitative criteria.
In emerging residential codes, these are also now becoming more precise. For example, in the energy efficiency provisions contained in NBC Section 9.36, where both material and assembly criteria are presented. (Notably Clauses 9.36.9 and 9.36.10.) Clauses in this code require a conforming air barrier assembly be qualified to CAN/ULC S742, Standard for Air Barrier Assemblies−Specification, or alternatively, with certain special conditions, ASTM E2357, Standard Test Method for Determining Air Leakage of Air Barrier Assemblies.