What are the characteristics, uses and advantages of glulam?
Glulam, short for glued laminated timber, is a type of engineered wood often confused with cross laminated timber that is becoming increasingly popular for use in various types of building construction and renovation projects.
At Usihome, we sometimes incorporate glulam into our prefabricated structural wood products due to its unique characteristics and advantages, which differ from traditional lumber.
In this article, you can learn all about glulam and get a feel for why this material is becoming so popular!
What is glulam?
Glulam is a type of engineered wood used as construction material. It is made by gluing together small wood slats (generally between 6 and 45 mm thick) that likely would not be used otherwise.
Once glued together with weatherproof structural adhesive, glulam can be used to build large pieces and unique shapes (straight or curved) that are valued for their mechanical strength, dimensional stability and aesthetic qualities.
Properties of glulam
Because the slats used to make glulam come from smaller trees, the adverse effects of knots and other defects on the mechanical properties of wood are lessened. As a result, glulam is generally sturdier and more homogenous than large, solid softwood lumber.
Moreover, since the slats are dried individually at the plant before being glued together, glulam is also more dimensionally stable than solid lumber.
Glulam manufacturing procedure
Manufacturing glulam combines two very old woodworking techniques: gluing and laminating.
To create solid laminate, multiple pieces of wood are dried and then stacked together with the wood grain parallel. (For cross laminated timber, the wood grain is placed perpendicularly.) Pine, larch, spruce, hemlock and even fir slats can be used, depending on the region.
To create effective structural elements, the slats must be joined together with waterproof adhesives so strong that they can replace the joins usually made by steel and screws.
According to the CCQ, glulam is considered “large lumber” once it reaches the minimum dimensions. It must therefore be manufactured in conformity with CSA O122 – Structural glued-laminated timber, and the manufacturer must be in conformity with CSA O177 – Qualification Code for Manufacturers of Structural Glued-Laminated Timber.
Based on evaluation criteria such as the allowable bending stress of the piece (x10² psi) and the homogeneity of the laminations used, glulam manufactured in Canada is graded as “generic” or “proprietary.”
Main uses of glulam
Glulam is recommended for all types of construction, from residential projects to industrial buildings.
This type of structural composite lumber can be used to manufacture various structural elements of a building:
- Floor joists
- Pillars and columns
Glulam can also be used to build a great variety of supporting arches and roof truss configurations.
Advantages of glulam
Glulam is becoming increasingly popular with contractors, who are using it in their residential, commercial and institutional construction projects.
It is prized for its many advantages.
It has a unique aesthetic
Various types of wood beams can be used to build the framework of a building, but few are as aesthetically pleasing as glulam. Its unique aesthetic comes from the variety of wood slats that make it up and their positioning, which can create interesting contrasts.
It can be used to create open spaces
Due to its high load-bearing capacity and low weight, glulam can be used to create large open spaces without the need for support beams. It can span up to 100 metres without intermediate support.
It is resistant to chemicals and humidity
Glulam has excellent resistance to various chemicals. It is also resistant to moisture-related damage such as warping.
It can be used to create curved beams and arches
Curved, bowed and bent shapes are very difficult to create with solid lumber. However, since glulam is made from small slats, the pieces don’t necessarily need to follow the structure of a tree.
It has excellent fire resistance
Glulam structures are less vulnerable to fire damage than non-fire-protected steel. In the event of fire, a charred layer forms around the core of the glulam, reducing oxygen consumption and delaying combustion.
Its dimensional stability is better than solid lumber
Glulam’s moisture content is around 12%, which corresponds to an equilibrium moisture content of 20 °C and a relative humidity of 65%, very similar to the conditions in most interior environments. This minimizes thermal expansion and contraction.
It reduces the need for joints and fittings
Glulam structures and frames may need fewer joints and fittings to span large open spaces without intermediate supports.
It is very light
The lightness of glulam makes it easy to install, maintain, and dismantle. Studies show that a glulam beam has the same strength as a concrete beam of the same volume, but weighs around five times less.
It is eco-friendly
Glulam promotes better use of forest resources, because it is manufactured with small pieces of wood that likely would not be used otherwise.
Furthermore, most glulam manufacturers use wood from reforested forests.
At UsiHome, we use structural composite lumber without hesitation
At UsiHome, we use glulam without hesitation to make prefabricated structures that are 100% adapted to our clients’ construction projects. That way, we can personalize the characteristics and appearance of our products.
Contact our team to find out how our products and expertise can contribute to the success of your next project!