Glue-laminated timber, better known as glulam, is a type of engineered wood used in both residential and commercial construction. There are many benefits to using glulam, especially in commercial designs, so if you're considering it as a building material for your next project, read on.
What is glulam?
Glulam is made from laminated layers of dimensional lumber -- usually spruce -- held together by strong, moisture-resistant adhesives. It comes in a variety of standard sizes and can be customized to precise specifications. The layers, which are called glulams, can be connected by bolts or steel dowels and plates to create columns, beams, and arches. Depending on the grade of the glulam, it may be used to build hidden supports in residential properties or in exposed structures like arches and vaulted ceilings in commercial properties. Exposed glulam can make for quite a beautiful aesthetic.
Why glulam is popular in commercial construction
Glulam is stronger than steel and dimensional lumber. It's a versatile building material that comes in both stock and custom sizes. Custom glulam is used more frequently in commercial real estate because of the larger spans and heavier loads involved. The glulams come in straight structures and custom shapes, like curved beams and radial arches.
The strength of the glulam is designated by four classifications per the American National Standards Institute (ANSI A190.1 Standard):
- Framing. Often used in home construction in concealed areas and in combination with dimension lumber.
- Industrial. Used in concealed areas, as it has surface imperfections.
- Architectural. Has an attractive enough finish -- or one with imperfections that can be covered up -- to be used as part of an exposed construction element, like the facade of a building.
- Premium. The highest grade of glulam; used for exposed elements in commercial construction that are highly visible to the public.
The advantages of glulam
If you're thinking steel beams are the only way to go in commercial construction or that wood beams are your only option for residential, then consider the many advantages of glulam:
- It's strong. Glulam can create 500+ feet of unsupported spans. Plank for plank, it's stronger than steel and dimensional lumber.
- It's cost effective. While glulam is more expensive than regular timber, it's similar in price to other types of engineered wood.
- It's environmentally friendly. While it is made of wood, it's produced in forests that are carefully managed according to the Programme for the Endorsement of Forest Certification (PEFC) standard. Glulam also has low levels of formaldehyde.
- It's easy to get. Standard sizes are readily available.
- It's also easy to customize. Glulam can be made with precision to fit a variety of custom designs.
- It's efficiently made. Glulam is made with small pieces of lumber as opposed to the long planks of traditional timber. This also cuts down on handling and shipping.
- It's fire resistant. Glulam might have gotten its start as wood, but the lamination process makes it stand up to fire even better than steel.
Glulam in all its glory
While glulam is often the go-to for many hidden applications, such as floor beams, rafters, trusses, and garage door headers, it also creates an attractive aesthetic when exposed, like in arches and ceilings. Examples of glulam in construction include Quebec's Mistissini Bridge and the Jackson Hole Airport in Jackson, Wyoming. Glulam's strength is on display in the 280-foot Placer River Pedestrian Bridge in Alaska's Kenai Peninsula, the longest timber truss bridge of its kind on the continent.
The bottom line
Steel and wood aren't the only construction material options around. Consider the benefits of glulam for your budget and your design for your next commercial project.