The Wonderful World of Wood (Mass Timber)
- iyanadoyle
- Mar 23
- 5 min read
When someone mentions a wooden building we should not assume that they're talking about a small single family home. Engineered wood products have allowed timber construction to reach much greater heights, literally! Today, there is an increasing number of mid and high-rise buildings being constructed that use wood as a main structural component and the excitement for more wooden buildings is only increasing due to that vast range of benefits that they provide!
What is Mass Timber ?
Mass timber panels are large-format panelized wood products made from solid sawn or structural composite lumber laminations. Cross Laminated Timber (CLT) and Glue Laminated Timber or Glulam (GLT) are commonly used mass timber products.
Cross Laminated Timber (CLT)
CLT panels consist of layered lumber boards (usually three, five, or seven) stacked crosswise at 90-degree angles and glued into place. Finger joints and structural adhesive connect the boards. The alternating grain of the lumber boards increases its strength and dimensional stability making it suitable for load bearing building elements like floor slabs, walls and roofs.
Glue Laminated Timber or Glulam (GLT)
Glue Laminated Timber is a structural, engineered wood product that is made by bonding or gluing multiple dimensional lumber pieces together, with the wood grain running parallel to the length of the member. Gulam is used for columns and beams in residential and commercial construction. Gulam beams can perform better than steel both aesthetical and strength wise, surpassing 100 ft.
Wood you? or Wood you not? - The Concerns With Timber Construction
Fire Safety –
We've all heard accounts of whole towns being completely destroyed by fire and having to be reconstructed repeatedly. This was common in the days prior to the advent of electricity when fire lamps and candles were commonplace. Open flames posed a constant treat to timber homes and by extension towns. Today, governments have created national building codes that aim to lower the risk of fire, and mitigate it's impact. In the Canadian National building code (NBC) for example, combustible buildings, like timber framed construction, was limited to 4 stories high if sprinklered, prior to 2015.
This was to ensure that in the case of a fire, fire fighters could effectively combat the flames using the resources that they had at their disposal at the time. The 2015 NBC increased the allowable number of stories for combustible construction to 6 stories. This change was made due to the advancements in sprinkler technology, fire alarm systems and the growing capabilities of firefighters. Improved fire ratings for combustible building assemblies and the increased effectiveness of fire separations are also to thank.
Introduction to Encapsulated Mass Timber Construction (EMTC)
Today, further improvements in building fire safety has enabled the NBC to allow for up to 12 stories of mass timber construction. The nuance is that if the mass timber used is encapsulated by a fire resistant material, like gypsum board, the building can be up to 12 stories high. The fire resistant encapsulating material allows the timber to have a much greater fire rating. Now that residential buildings up to 12 stories high can be built using mass timber, the growing demand for homes in Canada can be better filled by this environmentally friendly and cost effective alternative to concrete and steel framed construction. This is amazing news considering the plethora of benefits that timber buildings offer!
These are building construction materials that are capable of burning. Examples include wood, paper, plastics and various fabrics.
These are building construction materials that are not capable of burning or igniting under normal fire conditions. Examples include brick, concrete, cement, steel, ceramics, stone, and certain types of glass.
This is a construction assembly or barrier designed to prevent or slow the spread of fire and smoke between different areas or buildings, typically achieved through fire-resistant walls, floors, and doors, and is a crucial aspect of fire safety and building codes.
The time in minutes or hours that a material or assembly of materials will withstand the passage of flame and the transmission of heat when exposed to fire. The higher the fire rating, the more time people have to exit a burning building before it is completely engulfed .
Benefits of Mass Timber Buildings On Its Users:
Mass Timber is a low carbon, renewable alternative to concrete as its load carrying capacity is comparable to that of concrete.
The spanning capacity of mass timber surpasses that of steel making it a more attractive alternative to steel.
Mass Timber performs well in seismic events because of wood's lightweighted nature and inherent flexibility.
Mass Timber sequesters carbon, meaning it holds CO2 within its fibers and thus keeps some carbon out of the atmosphere.
The exterior walls (the building envelope), the interior partitions, and the floor assemblies can be prefabricated offsite, then assembled onsite. Making the construction process take only a fraction of the time that it takes for concrete construction. Mass timber construction sites are also significantly quieter for this reason.
The Future of Mass Timber Architecture: Sustainable, Strong, and Here to Stay
As the demand for sustainable and efficient construction solutions grows, mass timber is proving to be a game-changer in the built environment. No longer limited to small-scale structures, engineered wood products like CLT and Glulam are reshaping how we think about mid- and high-rise buildings. With advancements in fire safety, seismic performance, and prefabrication, timber construction is becoming a compelling alternative to traditional concrete and steel. Beyond its structural benefits, mass timber’s ability to sequester carbon and reduce construction time makes it a forward-thinking choice for a more sustainable future. As cities continue to evolve, the rise of wooden architecture signals an exciting shift towards greener, more innovative building practices.
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