Mass Timber Construction

ABOUT

This site contains useful resources for researchers, engineers, architects, contractors, and developers on moisture management practices and structural fire engineering for mass timber by providing links to design guides, webinars, white papers, and more from numerous organizations. Additionally, this site is a repository for current moisture management research and structural fire engineering mass timber research internationally under “Research Projects” and the products of mass timber fire research, in the form of publications, academic papers, and reports. This site aims to share the latest moisture management and fire structural design and construction practices across the industry in order to facilitate the industry expertise and durability of new and existing timber structures. To ensure the site stays comprehensive and updated, submit your own projects and/or resources through the form under the respective tab.  

About Moisture

MOISTURE AND MASS TIMBER

Although wood has potential for structural longevity, moisture can threaten its durability if not carefully managed for. Mass timber panels have potential to run into moisture problems from the manufacturing, shipping and storage stages, all the way through to construction and service life.

During construction wood often gets wet until a building is weather protected. In the case of dimensional lumber, sufficient drying can occur through heat, fans, and dehumidification. Engineered lumber, however, cannot dry as easily as dimensional lumber. If exposed to high levels of moisture during construction, checking and cracking can occur on the panels’ surfaces. If the surfaces of the panels do dry to acceptable moisture contents, that does not mean the inside of the panels also dried to an acceptable moisture content. Therefore, it is essential to limit exposure of mass timber panels to moisture and wetting. And it is critical to carefully manage the drying process in the case that panels do get wet.

In order to best manage moisture in mass timber construction, researchers and people in the mass timber industry are always trying to understand wood water relations better. Researchers perform tests on individual panels, assemblies, or full scale buildings to assess the affect various forms and intensities of moisture exposure on strength and form of engineered wood. Architects and engineers must take special care in detailing to protect joins, and exterior panels from allowing moisture to enter, but also allowing for moisture to escape out. Contractors and builders look to ensure that the panels are weather protected throughout construction.

Fire Guides about image

FIRE AND MASS TIMBER

Mass timber and tall wood structures are becoming increasingly popular, and building codes are rapidly changing allowing for taller mass timber buildings. These structures are considered to be quite innovative due to various sustainability advantages and the inherent fire-resistance properties of timber framing elements and products. However, to allow for exposed mass timber in high-rise buildings, the fire behavior of mass timber must be investigated to understand how a fire will impact the structural framing through charring and smoldering, and how the mass timber will impact the fire behavior within the structure. All of these investigations aim to better understand the fire behavior of mass timber so that engineers can design mass timber buildings to meet and potentially exceed the fire resistance requirements in the current code (there are many design codes that exist internationally that provide guidance for structural fire design). Once researchers perform tests on individual timber elements and understand their properties, architects, engineers, and contractors can use these results to better design, construct, and protect structures through a wide variety of applications.

 

Instructions for how to use the Think Wood Research Library and University of Minnesota's CLT Knowledge Database can be found here.