When considering the numerous cladding materials on the market, it is important to keep in mind there are really only two types: those that absorb moisture and those that do not. Absorptive claddings include wood, fibre cement, adhered veneers, brick, and stucco; the non-absorptive category encompasses metal, glass, and vinyl.
Flashings are critical to ensuring moisture does not have an opportunity to enter wall assemblies. However, many designers cannot agree on flashings because what constitutes the products themselves is poorly defined. A flashing is a material put in place to prevent water penetration, or to direct the water flow away from the building.
The road to energy independence is paved with conservation. In spite of new methods of producing ‘clean’ energy, nothing beats conservation as the most cost-effective solution. This is why recent changes to building codes—such as the new National Energy Code of Canada for Buildings (NECB)—have emphasized the requirements for airtight building envelopes and continuous insulation (ci).
Air barriers have been a requirement of the National Building Code of Canada (NBC) for many years, but not all design professionals fully understand what is involved in specifying one. An air barrier may be a material of many functions and the choice of one over another should reflect the needs of the particular project. Historically, the requirements for airtightness have been found under NBC Part 5, “Environmental Separation.”