attractive railing while maintaining this code requirement. Especially for decks and balconies which look out onto views, such design alternatives as glass, wire mesh and steel cable provide a measure of transparency while fulfilling the code requirement.
Note: In 2000, the International Residential Code contained a code (Section R316.2) which stated “Required guards shall not be constructed with horizontal rails or other ornamental patters that results in a ladder effect.”
In all subsequent issues of the code, Commercial and Residential, this dialogue no longer exists. The use of horizontal railing is allowed by code. It is always important to check with your local jurisdiction for code applications.
Although both cable as well as strand is often referred to as cable, there are differences between the two. It is important to know the difference when making the correct choice for your project.
A strand is form with two or more wires which are concentrically wound in a helix pattern. The wires are usually wound around a center wire. The following example is of a strand made up of 19 wires. Strands are referred to by a number code. The following example is a 1×19. 1 is for the single strand. 19 are for the configuration of 19 wires which form the strand. Strands tend to be more rigid and have less stretch to them. For this reason strand is favored for most railing conditions.
A cable is formed by combining a group of wire strands to create a wire rope.
Cable is referred to as the number of strands x the number of wires (ex. 7×7 would be 7 strands made up of 7 wires).
Because the way cable is constructed, it makes the cable more flexible and gives it more stretch. While cable is not favored for railing due to its properties, it can be used within shorter spans where bends might be required.
To simplify, I will refer to both strand and cable as just steel cable. Because of its strength and rigidity, steel cable can be used at 3/16” thickness in the 1×19 strand. This allows for more viewable area within the railing system.
To account for the 4” restriction it is best to design for a 3” vertical spacing between cables. This will account for a little give when vertical stress is applied so that the maximum separation will be 4” between cables.