Nail-Laminated Timber Design and Construction Guide

Canada


Specialized insight on acoustic comfort in innovative wood buildings 

Nail-Laminated Timber (NLT) is an old construction technique that’s enjoying new popularity. A common approach in the 19th century, NLT uses wood panels composed of ordinary lengths of lumber set on edge and nailed together. As with other forms of wood construction, a combination of fire risk and advances in other building materials – notably steel – caused NLT to fall out of favour in the early 20th century. Today, with fire risks dramatically reduced by modern sprinkler systems, builders are returning to this traditional technique for its simplicity, cost-efficiency and green credentials. 

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  • The Challenge

    Although NLT has long been accepted in official building codes as a form of Heavy Timber, until recently there has been no widely available design reference aimed at supporting the effective use of this construction technique. Seeking to advance high-quality timber construction “across industries, typologies, and geographies,” a group of skilled practitioners set out to develop a Canadian manual on NLT for the design and construction community. RWDI’s contribution to this important new resource focused on the unique acoustic challenges of NLT.

  • Our Approach

    Our contributions to theNail-Laminated Timber (NLT) Canadian Design and Construction Guide v1.0 were grounded in our team’s technical knowledge and extensive experience: we’ve promoted acoustic comfort and/or ensured code compliance in a range of innovative wood structures, including the University of British Columbia’s Brock Commons and the Wood Innovation and Design Centre in Prince George, British Columbia.

    The design guidance our acoustics, noise and vibration team contributed to the guide includes:

    • notes on how to reduce airborne sound (including sound that may travel through lamination gaps) through acoustics-aware design of NLT floor/ceiling assemblies, acoustic detailing, installation and finishing
    • guidance on floor/ceiling treatments that may help to reduce impact sound (from footfalls or other impacts) – the most common acoustic complaint in multi-residence buildings
    • insights on field testing NLT assemblies – especially as the existing database of assemblies remains relatively limited since the use of this technique is gaining momentum but is not yet widespread
  • The Outcome

    In November 2017, the Nail-Laminated Timber (NLT) Canadian Design and Construction Guide v1.0 was released for free download by anyone wishing to incorporate NLT into their design or construction work, enhance their NLT practices, or simply learn more about this inexpensive, sustainable and aesthetically pleasing material. The document represents an important milestone in the return to a 19th century building technique that’s proven itself to be remarkably well adapted to the challenges and sensibilities of the 21st.

    Ensuring that sustainable buildings are comfortable for occupants is important to the continued adoption of greener construction materials and techniques. Acoustic comfort is an area of concern for many professionals considering the use of Mass Timbre. We’re proud that our knowledge and expertise about acoustics in buildings that use NLT are part of this important reference document, which has the potential to guide and promote the adoption of innovative wood construction techniques across Canada and beyond.