Energy and thermal performance requirements are growing and playing an increasingly significant role in building codes throughout North America. However, understanding and meeting these requirements has also become complex for designers. At the same time, it is clear important decisions regarding basic enclosure assembly design and window area need to be made early in the project to achieve the most cost-effective, energy-efficient, and comfortable building.
Accurate assessment of the watertightness of new and existing roofs can potentially save building owners hundreds of millions of dollars annually. The challenge for roofing specifiers is choosing the most effective exterior-to-interior watertightness evaluation techniques because there is no single, straightforward method to accurately assess water ingress. It is, however, possible to obtain reliable information on the watertightness resistance and condition of an existing roof system by combining water-detection methods.
Even in winter, immediate replacement of roof systems could be an absolute necessity, depending on the severity of leaks and the interior environment the roof is supposed to protect. Contingent on the size of the roof, its complexity, and contractor availability, there may be time to squeeze in the replacement before snow falls. While roofing can be performed during the cold, winter months, there are many challenges that must be addressed by designers, contractors, and owners. These difficulties can be amplified when reroofing over an occupied facility.
Structural thermal breaks (STBs) address thermal weaknesses in the building envelope by ensuring continuous insulation (ci), thereby improving the overall thermal performance. They are also changing the design philosophy to an “envelope-first approach.”
Experiments conducted by RDH Building Science, National Research Council Canada (NRC), and a manufacturer of insulation materials have confirmed the presence of gaps between boards of insulation will cause a reduction in its R-value.
When selecting air barrier products to employ in building designs, architects have a broad range of choices. Spray foam insulation products are often selected because they can provide superior performance and also contribute to greater energy and operating cost savings in buildings.
The trend towards higher performing buildings and envelope systems requires a re-doubling of effort towards achieving durable, constructible, and maintainable transition details. There are many ways for these details to fail. Fortunately, there are also many opportunities throughout the design and construction process to focus on getting them right.
During the restoration of a clock tower in Huntsville, Ont., the contractor uncovered significant deterioration within the multi-wythe clay brick exterior walls. The project was expanded to include: demolition of the deteriorated brick walls, reconstruction of the tower walls one corner at a time, replacement of the steel roof, and recladding of the tower exterior walls.
The terms “air barrier” and “vapour retarder” (or “vapour barrier”) are perhaps some of the most poorly understood concepts in the construction industry. A general lack of understanding of the functions of these materials has resulted in simplistic rules-of- thumb. It is crucial the industry agrees on terminology that communicates the specific functions and purpose of these materials to avoid confusion and costly errors.
When waterproofing a walkable roof deck, there are a number of important principles to consider in determining the ultimate performance of not only the decking assembly, but also the waterproofing and the overall building envelope. These can be thought of as the Six Ds.
