DLT – Dowel Laminated Timber
StructureCraft is excited to announce that in fall of 2017, we will start manufacturing Dowel Laminated Timber (DLT), the only All Wood mass timber product in North America in our new 50,000sqft facility in Abbotsford, BC.
Dowel Laminated Timber (DLT) is a mass timber product that can be used for floor, wall, and roof structures. Historically, it is known as dübelholzin Europe. These solid wood panels use hardwood dowels to friction fit pre- milled boards together on edge, creating a panel which is particularly efficient for horizontal spans and allows for much architectural flexibility.
DLT panels are the only all wood mass timber product – in concept, they involve no glue or nails. With no metal fasteners, DLT panels can be easily processed using CNC machinery, creating a high tolerance panel which can also contain pre-integrated acoustic materials, electrical conduit, and other service runs.
Unique to DLT as a mass timber product, a wide variety of profiles can be integrated inexpensively into the bottom surface of the panel. Each finger-jointed board goes through a molder, allowing a limitless range of different profiles to be explored and exposed in the bottom of a panel.
Advantages of DLT
DLT panels are the only all wood mass timber product – they typically involve no glue or nails. As they contain no nails, DLT panels can be easily processed using CNC machinery, creating a high tolerance panel which can also contain pre-integrated acoustic materials, electrical conduit, and other service runs.
DLT is less expensive to fabricate than other glued products like CLT, and will come in at a lower price point. Some of the contributing factors to this cost advantage include:
- Greater structural efficiency than CLT (10-20%) – as all wood fiber goes in the direction of the primary span
- Lower manufacturing cost – due to high speed production and removal of need for gluing
- Ability to shape and surface – CNC machining creates accurately milled panels in efficient panel spans ready for rapid site installation
As an all-wood mass timber product, DLT aside from a minute amount of glue used for finger jointing, it does not contain any glue, chemicals, VOCs, or metal nails. The exclusion of glue and nails (which are seen in other mass timber systems) allows a healthier indoor air quality as there is no off-gassing. The timber we use is from sustainably managed North American forests and locks in carbon dioxide, acting as a carbon sink.
1655kg CO2 sequestered per tonne.
History of DLT
The concept of using hardwood dowels to connect softwood boards together was conceived in Switzerland in the 1990s. Julius Natterer spearheaded the development of brettstapel, as he believed that this efficient method of construction could be used to make beautiful, low carbon, healthy buildings that are quick and easy to build.
Several companies in Germany, Austria, and Switzerland adopted this idea and started manufacturing DLT commercially, using automated systems for drilling and inserting the dowels.