Cold Climates and Vapor Barriers
Calgary, being a colder environment, there’s a few options for the type of insulation to install in your home.
Perhaps more important than the type of insulation chosen, is the vapor barrier. The barrier and the insulation work together to create a warm, comfortable, and energy efficient home, but without a good vapor barrier, the home’s warm air will escape.
The barrier is just that, a barrier; it is what separates the warm air coming through the furnace and the cold exterior air.
In Canada, northern USA, or in any cold climate, the vapor barrier needs to be installed on the conditioned side of the insulation or the interior side.With the vapor barrier on the warm side of the home, the cold air is kept from creeping in.
#1 – Closed Cell Spray Foam
When it comes to the actual insulation product, two-pound closed cell spray foam is the best way to go in colder climates. Spray foam is an airtight, permanent product that lasts, well, permanently if installed correctly. One of the great things about spray foam is that it is both insulation AND a vapor barrier all in one.
#2 - RockWool
The second best is RockWool, or mineral wool. A perhaps lesser-known product, mineral wool is a great alternative to fiber glass, and it has a lot of the same benefits of spray foam. It can be used anywhere fiber glass is used.
RockWool is noncombustible and fire resistant; it works to keep the fire from spreading and will not emit toxic smoke even when exposed to flames. It is also water repellent, so it will not expand and contract with temperature changes.
#3 - Fiberglass
The third best is fiber glass. It is the most commonly used insulation as it’s also typically the least expensive and relatively quick and simple to install. Before the fiber glass can be put in, a vapor barrier will need to be properly installed to ensure the warm air stays where it should – inside.
Cellulose insulation also has a place, but it is used specifically for attics, not for exterior walls.
Hot and Dry Climates
In warmer climates, it’s not really about the type of insulation used, but how it is installed.
In Canada or other cold climates, the vapor barrier is installed on the interior side of the insulation. In warmer areas, like far south USA, the vapor barrier is installed the opposite way: on the exterior side. That is, if there’s a barrier installed at all as sometimes it’s not needed.
In southern areas, homes are being cooled to be more comfortable, so the vapor barrier installed on the outside helps move the air to keep the home cool. This is called a vapor drive because it helps the vapor drive differently: from hot to cold rather than from cold to warm.
#1 – Open Cell Spray Foam
Open cell spray foam is the preferred way to go in hot and dry climates.It’s less dense than closed cell foam and allows moisture to pass through it. As noted above, sometimes a vapor barrier is needed, but in warmer climates, sometimes it’s not required.
#2 – Fiberglass
Fiber glass is a good insulation product to use because it’s a well-rounded material that checks all the boxes for good insulation. The biggest selling feature on fiber glass is that it's cheap and widely available.
