There are various methods and products for constructing cable railing, from complete guard systems to simple cable and turnbuckle products. These manufactured products must be installed according to the manufacturer’s requirements. Adhering to the installation instructions will give you as close of an installation as possible to that which was originally tested. Guards at the edge of elevated decks have an important job in resisting the force of people leaning or falling into them. Manufacturers must either engineer or test their products to prove they will support building code design loads; typically they test them.
Cable railing is a hybrid of materials, as the cables are installed in frames of wood, aluminum or composite. Generally long cables can run straight through intermediate posts, allowing for faster installation. Care must be taken to properly align the holes as their location governs the spacing of the cables. Drilling in from both sides will ensure alignment. At corner posts, cables are usually terminated in a turnbuckle and a new cable is connected on the side to continue around the deck.
Stainless steel, the common material for cable railings, is relatively soft steel and will stretch over time. Expect to periodically tighten the turnbuckles as the cable stretches to its general limit. Be sure to leave threads available during installation in anticipation of this future maintenance. Building codes require guards to have spacing that does not allow a 4-inch sphere to pass through, so it’s recommended to space the cables no greater than 3.5 inches. This will provide a little safety factor in case loose cables in the future are not promptly corrected.