High Exposure Fenestration Installation

Originally published in Glass Canada Magazine, August 2020 Issue

To the casual observer, a window is just something you look through to see outside and there’s not a lot of thought given to it beyond that. For people involved in the application and installation of fenestration products however, there are a mind boggling number of intricate details that have to be considered and addressed. A slip up or oversight on any one of them can result in leaks, condensation, and mold, all of which are going to cost someone a lot of money to mitigate.

To provide a roadmap to follow from design concept through detailing, testing, installation, and final inspection, the Canadian Standards Association has recently released a new national standard entitled CSA A440.6:20 “High Exposure Fenestration Installation”. This Standard applies to the installation of fenestration products in buildings of four or more stories in height of all occupancies, including residential: punched and ribbon windows, window walls, curtain walls, and storefronts. According to the standard, “the users of this document include persons engaged in the design, selection, and detailing of fenestration products and their installation into wall or roof assemblies, installers of fenestration products, specifiers of fenestration systems, technical staff of fenestration manufacturers engaged in designing fenestration systems, and persons and organization that train fenestration installers.” I was very impressed by the amount of detail covered at every step of the process and with the illustrations provided to support the directions and recommendations.

“Improper installation of fenestration products can reduce their effectiveness, including causing excessive condensation, unacceptably high levels of air, water, and sound leakage, and deterioration of the wall and roof systems into which they are installed. This Standard was developed to address issues that can adversely affect the performance of fenestration products when installed in building walls and roofs, and into both new and existing buildings subject to high environmental exposures.”

Besides outlining all the steps from start to finish of a window project, the standard also contains a lot of very useful reference material that I could see myself looking for when working on a job. There is a section on caulking that includes joint design size as a factor of temperature range expectations as well as a table identifying the sealants that are compatible with surrounding building materials. There are also good details on anchorage and recommended anchor types that vary by the substrate they are attaching to. The sections on treatments to ensure the continuity of the critical barriers: air, vapour, and water, were most informative.

Something I saw being addressed for the first time in this new standard was a forward looking section on the effects of anticipated climate change and how it could impact fenestration product design and application. Changes in temperature, precipitation, and humidity affect the level of various elements in the air, such as salt and pollution that could lead to accelerated degradation of some fenestration and building materials. The standard reviews climate data and tries to predict future weather based on 4 different models. This is turn is intended to be used when considering the performance requirements of the window products taking into consideration that the lifetime of a building will be 50 to 100 years.

From what I see in this new standard, I believe it won’t be long before it is being referenced in project specifications and being used by every design office. It will be in the hands of every consultant and quality assurance person on your jobsites so it wouldn’t be a bad idea to get a copy of it now to get ahead of the curve. I’m pretty sure you’ll find a lot of information that will help you a lot and that you can put to immediate use on your projects.

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