For the average homeowner, airflow in the home comes down to the basics: heating, air conditioning, or opening the front door and some windows for a flow-through breeze. We take it for granted, without understanding the dynamics of our indoor environment, and without realizing the potential effects on our health and comfort. Truth is, there’s no reason to understand more than the basics - the essentials are best left to the experts.
Airflow actually affects everything inside the home. The moisture in the air, for instance, has an impact not only on our comfort, but also on the structure itself [like the wood, the drywall, even the exterior stucco]. And airflow can also affect oxygen levels in the surrounding air, not to mention the spread of various pollutants and mould-inspired concentrations, which we don’t always notice.
One of the most important considerations for the proper management of interior airflow is the application of air barriers. In general, air barriers are the materials used to manage and maintain airflow between the inside air (known as “conditioned space”) and the outside air (“unconditioned space”). In multiple unit complexes, like a townhouse or apartment, the air barrier system also separates the individual residences.
Most notable for the homeowner is probably the air barrier that separates the garage from the indoor space, specifically for preventing dangerous gas fumes and exhaust from entering the residence. Just imagine the consequences of a breached or ruptured air barrier, and the potential outcome. Needless to say, it’s just as important to consider the over-all integrity of air barriers throughout the entire home.
Air barrier systems are designed to ensure that outside air is kept out, and inside air is kept in, all the while maintaining a proper balance between airflow, circulation and ventilation. In every residential scenario - new home, renovation, or retrofitting – the air barrier system must be impervious to air flow. As well, there should be continuity throughout the structure - a “patchwork” approach will only create more problems.
As mentioned prior, the complexities of product options and mechanical installation are best left to the experts. These are professionals with industry knowledge; with experience and expertise to assess a homeowner’s specific needs; and with the know-how to recommend an appropriate action plan that suits the task at hand. However, an informed and educated homeowner is best positioned to work in tandem with the expert.
When it comes to air barrier products, it’s important to be familiar with the options, but to take advice from a professional at the same time. Every situation is unique, and every solution should be customized to suit. You may opt for a “house-wrap”, something made of polyethylene or polyolefin, which performs as a moisture barrier and an air barrier. Or you may decide on an adhesive membrane, which will act as a water barrier and a vapor barrier simultaneously. Or you may want some kind of fluid membrane, such as a poly-coating or asphalt-based material. Then there’s polyurethane spray foam, which does it all, and provides insulation as well. In the end, the best approach is one that combines a good level of consumer savvy with the expertise of a professional.