Manufacturing Process of CLT

Manufacturing Process of CLT

A Cross Laminated Timber panel consists of several layers of kiln-dried lumber boards stacked in alternating directions, bonded with structural adhesives, and pressed to form a solid, straight, rectangular panel. CLT panels typically consist of an odd number of layers (usually, three to seven or more). This cross lamination provides dimensional stability, strength and rigidity, which makes CLT a viable alternative to conventional framing, concrete, masonry and steel in many applications. It can be used for an entire building, as both the lateral and vertical load resisting system, or for select elements such as the roof, floors or walls. CLT as a structural panel element is also used as a superior industrial matting, bridging and retaining wall product that replaces heavy timbers, steel, and concrete.

Lumber Selection We use Douglas Fir, Western Larch & SPF Grade 2 and Better.

Lumber Drying The boards are kiln dried to a moisture content of 12% +/- 3%. Proper moisture content provides for proper adhesion and prevents dimensional variations and surface cracking.

Defects According to the strength and final visual quality, defects such as large knots and resin or bark pockets are removed.

Finger Jointing The boards are trimmed and finger jointed to obtain the desired lengths and quality of lumber. SmartLam can produce solid wood panels up to 41’ long. Our new plant will be capable of producing panels 12′ wide and 64′ long.

Panel Assembly Panels are assembled by placing the finger-jointed boards side-by-side (to achieve the desired length & width) to form solid wood layers. Each succeeding layer is laid perpendicular to the preceding layer.

Adhesive & Press Each layer is sprayed with adhesive and the entire “sandwich” of layers is then pressed vertically and horizontally in a large hydraulic press. Our adhesives are waterproof and fire-resistant polyurethane; solvent-free and formaldehyde-free.

Fabrication Assembled panels are cut to size, milled to spec, and finished as required by our Hundegger CNC Panel Fabricator. This 4 head/5 axis CNC Fabricator is capable of milling nearly any design specification.