A company specializing in materials for high-performance buildings has published the second in its series of ebooks on building techniques, this one focused on the use of I-joists.
High Performance I-Joist Assemblies discusses modified Larsen truss construction for Climate Zones 4 and greater. It offers a short history of the I-joist — invented in 1969 for use in floors and roofs — before going on to explain how they can be used as structural and non-structural elements in the walls of high-performance buildings.
Like its predecessor, this book also makes the argument for foam-free building assemblies. “Foam plastic insulation dominates high performance and green construction today,” the introduction says, “a clear victory of the power of chemical company marketing over common sense.”
The book says that plastic foam insulation contains toxic ingredients, is a fire hazard, and can lose its thermal insulating properties over time. Instead, the authors make the case for cellulose, fiberglass, and mineral wool insulation.
What’s in the book
The book covers four main topic areas, beginning with “ground,” the connection of I-joist construction to a number of foundation types. There also are chapters on exterior wall assemblies; penetrations through walls, including windows, doors, pipes and wires; and roofs. Finally, there’s a description of the various materials that 475 sells.
In each area, the book includes color-coded drawings with details on interior and exterior air sealing. Both the text and drawings emphasize the importance of controlling air leaks and moisture.
If you’d rather have the book in hardcover form, it can be ordered for $35 with delivery scheduled for August. Readers also can download CAD files of details explained in the book for free.
The book is a beta version, so readers may find a rough spot or two in the text. But 475 says it welcomes feedback and plans to offer additional books in the future.
Since 475 is a retailer of materials used in high-performance buildings, such as sealing tapes and building membranes, readers shouldn’t be surprised that the book, a marketing effort by 475, promotes several brand-name products.
475 co-founder Ken Levenson, an architect, is co-president of the North American Passive House Network and president of New York Passive House.
Get building science and energy efficiency advice, plus special offers, in your inbox.