Nail Laminated Timber – NLT
NLT (Nail Laminated Timber) is a mass timber panel system which can be used for floor, wall, and roof structures. Tall wood buildings like T3 Minneapolis are using NLT as floor and roof panels atop Glulam beams.
We will be phasing out most production of NLT over the next year as we commence our automated production of Dowel Laminated Timber (DLT) in Q4 2017, a similar mass timber product that utilizes 100% wood (no glue, no nails).
NLT will continue to be produced as required by specific projects, or to create freeform geometry / warped panels.
Nail-lam floor and wall assemblies have been used for more than a century, particularly in warehouses where solid, sturdy floors were required. It is now being recognized again as a valid substitute for concrete slabs and steel decking in commercial and institutional buildings, and residential buildings in which it is often exposed to create a unique aesthetic. In addition to being used in floors, decks and roofs, mass timber panels are now often used for the timber elevator and stair shafts in six-storey, light-wood frame residential mid-rise apartment buildings.
NLT is created from dimensional lumber stacked on edge - 2x4, 2x6, 2x8, 2x10, or 2x12 at 1-1/2" on center - and fastened together with nails. Plywood sheathing is often added to one top side to provide a structural diaphragm. Plywood sheathing also allows the product to be used as a wall panel element.
In much the same way as tongue-and-groove wood decking, NLT is sanctioned by building codes in both Canada and the USA (NBCC and the IBC). NLT qualifies as Heavy Timber as long as it is "well-spiked together" and the depth is at least 64mm for a roof and 89mm for a floor (see NBCC 22.214.171.124 4b/6b and IBC 602.4.6.1). As such, it does not require an "alternative solution" application.
The depth of an NLT panel depends on loads and spans - we have prepared an NLT Design Guide which includes span tables, typical connection details, and more.
Width and length of panel only limited by shipping and erection constraints
Our NLT Fabrication Process
Because clients appreciate the simplicity, aesthetics and economics of NLT, we have incorporated it into many of our recent projects, and have set up a production line to create a high-quality product inside our shop. After carefully grading the lumber, we pre-fabricate large panels of NLT, pre-install the plywood sheathing, finish the underside, ship the slabs to site, erect them onto the support structure and finish up the joints with simple plywood infill strips. The result is a structural floor or roof system with an appearance-grade soffit which can be exposed to view as the ceiling for the space below.