How do you frame a mass timber building? Is the best way to do it 100% as timber, or should you utilize a hybrid approach incorporating other structural materials? Bearing walls vs. post and beam vs. post and plate? How does project use and size affect these decisions?
So what happened in 2021 in the world of mass timber? Here are my top takeaways from a very full year of mass timber design and construction in the US.
One of the biggest misconceptions about timber buildings is that they do not perform well in fire. Although mass timber elements can be encapsulated in gypsum wallboard or a similar material to achieve the required fire-resistance rating, most designers and owners prefer to leave the timber elements exposed.
Mass timber is a unique building material and, to set a project up for success, there are some critical decisions that should be made as early as possible. These decisions can have a big impact on cost and can either increase or limit opportunities later in design.
While there is no single answer as to what makes a mass timber project successful vs. not moving forward with it, there are some common themes that are evident in many mass timber projects which do realize completion. In this video, I break down a list of 10 items that can help lead a mass timber project to success.
Mass timber panels including cross laminated timber (CLT) have the ability to span in 2-directions, using structural properties obtained in both the major and minor panel axes. Doing so can result in a beamless system often referred to as Post and Plate (a framing configuration also used in flat plate concrete construction).
Is there a building size, height, number of stories, or occupancy in which mass timber works the best? In this video, I take a look at optimizing mass timber for a variety of projects, but rather than looking at this from a size and scale perspective, the focus is on structural material replacements for other systems in which mass timber works well - particularly post and beam framing.
A benefit associated with the use of mass timber construction that is commonly cited is the reduction in foundations - specifically the ability to make foundations smaller than what they would be if the building were framed with other, heavier materials. However, the required size of the foundations in a building is based on more than just the weight of the structure.