History of Glued Laminated Timber

Early Experiments (1800s)

The principle of laminating timber to produce larger structural members was explored throughout the 19th century. Builders and engineers recognised that bonding smaller boards together could overcome the natural size limitations of individual trees and produce members with more consistent properties.

One of the earliest surviving examples of laminated timber roofs was built for King Edward VI College in Southampton, England. These early members used natural glues (casein and animal-based adhesives) that were adequate for dry interior conditions but had limited durability and no resistance to moisture.

The first recorded building constructed with what we now recognise as glulam was an auditorium in Basel, Switzerland, completed in 1893. The laminated timber frame demonstrated that small boards could be bonded into strong structural members capable of supporting significant spans, but the adhesive technology of the period meant these early members were restricted to dry, protected environments.
 

The Hetzer System (1900-1920s)

Otto Karl Friedrich Hetzer, a German carpenter and inventor, transformed laminated timber from an experimental technique into a systematic construction method. In 1901, Hetzer obtained a patent for bonding straight timber beams from multiple laminations. He subsequently patented a method for manufacturing curved laminated arches, a development that opened glulam to the long-span and architecturally expressive applications that remain its primary territory today.

Structures built using the patented "Hetzer System" appeared across Europe in the early 1900s. The system was licensed to engineers and builders in other countries, and by 1922, glulam construction had been documented in at least 14 countries. The appeal was clear: laminated timber could produce long-span roofs and arches that solid timber could not achieve, while making efficient use of smaller-dimension boards.

Figure 1: Construction process of the girders in Niederurnen in 1912

The limitation remained adhesive durability. Early glulam used casein and other non-waterproof glues, restricting the product to dry interior applications. Structures exposed to moisture risked delamination, a problem that would not be resolved until the development of synthetic resin adhesives in the 1940s.

Glulam Enters the Mainstream (1930s-1950s)

In 1934, German-born engineer Max Hanisch designed a school gymnasium in Peshtigo, Wisconsin, the first building in the United States constructed with structural glued laminated timber. Local authorities were initially sceptical of the novel material and required additional bolts and metal straps as a precaution, but engineers from the United States Forest Products Laboratory tested and validated the design. Load tests demonstrated that the glulam arches were strong and, notably, more fire-resistant than steel beams under comparable test conditions.

Figure 2: Interior of the school gymnasium in Peshtigo, Wisconsin, built in 1934. This building remains in service today — over 90 years of continuous use.*

Figure 3: The Peshtigo design inspired many other school hall designs in the region, such as this gym at Tinley Park High School  (photographed 2018). Source: Illustrious Gyms.

The Second World War accelerated glulam's adoption. Steel scarcity drove engineers to use laminated timber for military hangars, warehouses, and long-span industrial structures. In 1942, the introduction of phenol-resorcinol adhesive, the first fully waterproof structural timber adhesive, removed the moisture limitation that had constrained glulam to interior applications since its inception. For the first time, glulam could be used reliably in exterior and high-moisture environments: bridges, canopies, outdoor structures, and exposed architectural elements.

By the early 1950s, glulam had entered the construction mainstream, with manufacturers established across North America, Europe, and Australasia. In 1952, North American manufacturers formed the American Institute of Timber Construction (AITC), establishing industry standards and quality assurance programs. The first national structural glulam standards followed in 1963.

Glulam arrived in Australia during this period, with local manufacturing commencing in the 1950s. Australian production has continued since, governed by AS/NZS 1328.1 and supported by the Glued Laminated Timber Association of Australia (GLTAA).

Ambitious Structures and Modern Development (1960s-Present)

From the mid-20th century onward, glulam was applied to increasingly ambitious structures. In 1966, the Keystone Wye interchange in South Dakota used glulam arches for two highway bridges, a bold demonstration of engineered timber in heavy-duty infrastructure that remains in service today.

Figure 4: Keystone Wye Interchange in South Dakota from above

Figure 5: Keystone Wye Interchange in South Dakota from below

Through the late 20th century, glulam established itself as a trusted material for schools, churches, sports facilities, exhibition halls, and cultural buildings — any application where long span, curved form, or expressed timber structure was valued.

The development of CNC machining technology from the 1990s onward transformed glulam fabrication. Computer-controlled cutting, drilling, and profiling enabled complex connection geometries, tight tolerances, and seamless integration with digital building design (BIM). Modern glulam members arrive on site with all connection details pre-machined — a level of prefabrication precision that earlier generations of glulam builders could not have achieved.

Today, glulam is experiencing renewed momentum as part of the broader mass timber movement. Modern engineers pair glulam beams and columns with CLT panels to create post-and-beam and post-and-plate structural systems for mid-rise commercial, institutional, and residential buildings. Advances in adhesive technology, automated manufacturing, and fire engineering have expanded the product's range and reliability.

In Australia, projects like Bunjil Place (Melbourne) and The Cutaway (barangaroo) demonstrate that the architectural ambition of the Hetzer era continues, now supported by 130 years of engineering development and a mature manufacturing industry.