Dowel Laminated Timber (DLT) Design + Construction
All wood. All good.
What is DLT?
Dowel-laminated timber (DLT) is common in Europe and is gaining traction in the U.S. for its ease of use with computer-controlled (CNC) machinery—such as lathes, routers and mills—and its all-wood composition. DLT is similar to nail-laminated timber (NLT). Instead of nails or screws, however, DLT uses wood dowels to join laminations.
How It Works
DLT is similar to nail-laminated timber (NLT), without the use of screws or nails. To form DLT members, softwood lumber panels are stacked like NLT and friction-fit together with hardwood dowels. The dowels hold the boards together, and the friction fit—achieved by the differing moisture content of the softwood panels and the hardwood dowels—affords additional dimensional stability. Dowels also can be inserted diagonally, offering additional resistance. Because DLT does not use nails or screws, it is easier and safer to mill and route. The lack of an adhesive is also attractive for projects looking to maximize the use of wood.
How It's Used
DLT is a next-generation mass timber product that allows for significant architectural flexibility and is well suited for horizontal spans. In application, DLT performs similarly to glulam and NLT. Because its grains run in one direction, DLT is best suited for flooring and roofing applications.
It also helps designers improve a project’s acoustics and visual appeal through the addition of curves and kerfs. Acoustical strips can be integrated into the bottom surface of a DLT panel, helping designers mitigate sound while keeping wood exposed and allowing for a variety of surface finishes.
Learn more about DLT in this podcast episode with Lucas Epp of StructureCraft Builders.
Case in Point
Pulpit Rock Mountain Lodge
DLT is still nascent in the U.S., but it features prominently in European projects, including the Pulpit Rock Mountain Lodge in Strand, Norway.
The 24-room hotel is shaped by prefabricated floor, wall, and roof panels made of DLT. It is designed to let visitors take in views of the breathtaking natural landscape that surrounds the site. Learn more about how DLT was used in this project by visiting the website of its architect, Norway-based Helen & Hard.
