Is cable railing safe?
When Built to code, cable railing is a very safe option for railing. However, Building code can be hard to navigate. Here you’ll find helpful information about horizontal railing codes, and how Viewrail cable railing products are designed to exceed those code requirements without sacrificing on design.
Codes Affecting Cable Railing
A number of code stipulations will apply to your project given its environment: residential or commercial. While there are some standards for railing in for both residential and commercial, local code can have important minor differences. We always recommend verifying your project details with a local code official before finalizing a project. Most-often, horizontal railing systems are subject to the Sphere Rules, Handrail & Guardrail Height Requirements, and Load Requirements.
During any cable railing project, you’ll hear reference to the 4” Sphere Rule, and, if stairs are involved, the 6” Sphere Rule.
4” Sphere Rule
The 4” Sphere Rule refers to gaps & spaces within a railing system. The rule states that a 4” sphere should be unable to pass through any gap in a railing system. This is why Viewrail posts are drilled with holes 3 ⅛” center-to-center, to avoid any deflection exceeding 4 inches.
6” Sphere Rules
The exception to the 4” sphere rule is the gap created between the bottom run of infill and the 90 degree angle created where the rear of a stair tread meets a stair riser. The rule states a 6” sphere should be unable to pass through this triangular gap.
Handrail & Guardrail Height
Handrail & guardrail are commonly confused as being the same component of a railing system.
Guardrail refers to the structural railing element that sits atop a railing system. A guardrail is typically required for stairs with 4-or-more risers, or for a deck or balcony with 30 inches above grade. Code requires guardrail in residential structures be a minimum of 36 inches. Some areas require taller guardrail. Be sure to check with your code official regarding your area’s guardrail height requirements.
Handrail refers to a graspable element of a railing system designed to assist you in ascending or descending a staircase. Code requires handrails be mounted between 34 and 38 inches. Code also requires handrails return into a wall or structural member of the railing system. This allows everyone from homeowners to first responders to safely traverse a staircase without snagging clothing or equipment on a handrail and falling down a staircase.
Force & Load Requirements
Another common code requirement you’ll hear about during a horizontal railing project covers load requirements, or a certain amount of pressure either applied to a specific point of a railing system or distributed throughout the system by linear foot.
Handrails and guardrails and structural members of a railing system are required to withstand 200lbs of concentrated force in any direction. Intermediate structures are only required to withstand 50lbs of concentrated force.
At Viewrail, we’ve tested each part of our system to a 4x safety factor to ensure our systems are as structurally sound as they are aesthetically pleasing.
To ensure your system performs as well as designed, be sure to space structural posts 4ft apart center-to-center. If you’re using a wood post system, you’ll need a structural post every 8ft with intermediate (non-load-bearing posts) spaced every 4ft between structural posts.
This measure also ensures your cables will remain properly tensioned and deflect as little as possible.
Following our cable railing installation guide is essential to a cable railing system that will perform optimally for years to come.
Pro Tips for Proper Tension:
- Measure twice, cut once is an old adage for a reason. The more precise your cuts, the less likely you are to bottom out the threads on your tension receivers.
- Always crimp your cable railing components twice.
- Follow the tensioning diagram, beginning with your center-most run of railing and alternating towards your outer-most runs at the top & bottom of your posts.
- Be careful not to tension your cable railing too much – in some instances, this can bow handrail.