Glulam, laminated beams and spectacular glulam structures

GLULAM is the international term used for lamellar beamsThe term comes from Glued Laminated Timber. The product is a wood composite made of layers of timber (planks) joined end-to-end to the desired size, which are glued together under pressure, across the width, with a very strong adhesive.

A durable material used successfully in construction

Laminated beams are used to make load-bearing structures, i.e. posts, beams, frames, etc. They can also be obtained in curved shapes, with a bending strength 50% higher than that of solid wood. Also, creating this sandwich reduces the stresses that occur in solid wood, resulting in a material that warps and cracks more slowly.

Another advantage of the material is that it allows the elimination of certain defects in the timber, knots, cracks, which would create problems in a strength structure. The pieces resulting from the removal of the defective parts are joined into teeth and then glued together. The adhesive layers formed make the material fire resistant. When fire reaches the adhesive, it extinguishes itself.

One of the earliest still standing buildings to use glulam beams for roof construction is the assembly hall of King Edward VI College in Southampton, England and dates from 1866. It now functions as the town hall marriage hall.

A history of almost 150 years

The first industrial patent, however, was registered in Weimar, Germany, in 1906 by Otto Hetzer, a very inventive German. As early as 1872, he had already put into operation a steam-powered gater and joinery machine. Here he developed many innovative ideas which he began to patent in 1892. The patent registered in 1906 is practically the birth certificate of the lamellar beam.
In 1909, Terence&Chopard, a Swiss construction consulting firm, bought the patent and used the beams in a number of projects.

One of the projects was the Zurich Institute of Hygiene of that time, built in 1911, later part of the University of Zurich. The bell-shaped dome, then built using lamellar beams, is still visible today.

In the US, laminated beams arrived in 1934, thanks to Max Hanisch Sr. who worked with Otto Hetzer around 1900. He sets up a company in Peshtigo, Wisconsin, which will begin industrial-scale production.

A very important moment in the history of glulam is 1942. In this year a totally waterproof adhesive (phenol-resorcinol adhesive) was introduced, which allowed the use of beams outdoors.

The strength of the lamellar beams makes it possible to build spaces with large openings

Now the beams are used to build sports arenas, industrial halls, bridges, museums, concert halls and many other impressive constructions.

Due to their very high load-bearing capacity, even at long lengths, they allow for constructions without resistance columns, with large spans. This allows architects to let their imagination run wild and create spectacular constructions.

There are also known factories of laminated beams in Romania at Ulmi, near Targoviste, at Joseni, Harghita or at Voiteg, Timis. There are many sites that have been developed using glulam, one of them being the Salina Turda.

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