Connection Types in Wood-Frame Buildings (2)

4. Proprietary Connections Proprietary connections combine the characteristics of dowel, metal connector plates and shear. They are part of the most innovative connection systems. Generally, proprietary connections are produced by a professional manufacturer or designed specifically for one building. These connection systems and similar products are more and more developed for use in larger and more complicated buildings, which are designed to take advantage of the economic, aesthetic and environmental benefits of wood. Customized structural framing connections, generally composed of bent or welded steel, can transfer load from the supported member (through direct bearing) to the supporting member by hanger flange bearing, fastener shear or both. They can provide a single-piece connection between two framing members. Another proprietary connection is pre-engineered metal connector, which is usually used in all kinds of wood building. Though Common type of pre-engineered metal connectors, like metal hangers, as well as traditional fasteners (nails, bolts and rivets) are widely used and more reliable, they have inherent weakness limiting the use in large and complex buildings. So it’s necessary to develop new proprietary systems. New systems, often concealed, can make them fire-resistant when they are sufficiently below the wood surface. They can be used without impacting the strength of the wood and be designed stiffer or more flexible. It depends on their application. In fact, proprietary products are becoming widely used now. We can see the self-tapping and self-drilling screws are more and more used in cross laminated timber and glulam structures. They are produced with different features and in many shapes and sizes, to enhance hardness for higher lateral load capacity and various other capacities for different applications. With a regular hand-held power drill, they can be driven into wood without pilot holes, which is their main advantage. In this way, the ris