About glulam

Photo: Christian Ljung

Structure

Glulam (glued laminated timber) comprises a number of wood laminates glued together. The fibres in the laminates run parallel to the length of the piece. In straight glulam products, the laminates are 45 mm thick. For curved products, the thickness is less, generally 33 mm.

Glulam is a construction material that comes in a range of strength classes. The manufacturing standard for the Swedish market is strength class GL30. Some glulam beams are made by splitting glulam beams of class GL30 to create split timber beams, which then have a strength class of GL28.

Glulam sets no limits on the potential for wood construction techniques.

Glulam beams are made with laminates of a higher strength class on the bottom and top, where the maximum tensile and compressive stresses occur. The rest of the cross-section, where the stresses are lower, uses laminates of a lower strength class. The manufacturing method is called combined glulam and is usually indicated with the letter c after the strength class designation. This allows more efficient use of material compared with only using wood of the same strength class.

Alternatively, glulam may be made with laminates of the same high strength class throughout, and this is represented with an h for homogeneous after the strength class designation. Glulam is available in a large number of dimensions. Read more under Range.

Custom manufacture

Where large spans, loads or other circumstances define the design, glulam is made to the drawings and accompanying specifications as required, in consultation with the glulam manufacturer’s structural engineers. Custom-made glulam elements are available in practically any shape and dimension to meet the architect’s vision and other parameters.

Examples of common custom glulam products include curved beams, pitched beams, portals and arches. Contact one of the glulam manufacturers for more information.

Glulam has a good environmental profile in manufacture and use.
Photo: Johan Ardefors.

Why glulam?

  • Styrka – I förhållande till sin vikt är limträ ett av de starkaste konstruktionsmaterialen.
  • Miljö – Råvaran är förnybar. Limträet kan återanvändas eller återvinnas.
  • Skönhetsvärde – Limträ är en estetiskt tilltalande och en miljöskapande produkt.
  • Energi – Energianvändningen vid limträtillverkning är mycket liten jämfört med andra konstruktionsmaterial.
  • Beständighet – Limträ klarar aggressiva miljöer bättre än många andra konstruktionsmaterial.
  • Formbarhet – Limträ kan tillverkas i praktiskt taget vilken form som helst.
  • Formstabilitet – Limträ varken vrider eller kröker sig.
  • Brandmotstånd – Limträ motstår en brand bättre än många andra konstruktionsmaterial.
  • Bearbetbarhet – Limträ kan bearbetas med såväl enkla handverktyg som med maskinella verktyg. Hål och urtag kan göras i limträ efter samråd med en erfaren byggnadsingenjör/-konstruktör.

Copperhill Mountain Lodge , Åre.

Glulam is the future!

    • Glulam sets no limits on the potential for wood construction techniques.
    • The glued laminates make glulam both strong and stiff.
    • Glulam is one of the strongest construction materials in relation to its weight. This means that glulam beams can freely span large distances.
    • Architects, structural engineers and users have great freedom to create their own shapes using glulam, whether for the structure of a house, a roof for a public building or a wooden bridge.
    • Glulam is a construction material that optimises the technical properties of the renewable raw material – wood.
    • Glulam is made from individual laminates of construction timber and ensures efficient use of material.
    • The laminates are finger-jointed to produce long lengths and then bonded together to create the desired dimension.