In today’s residential trends, homeowners want more accessible space in their homes and more connection to their natural surroundings. That’s why some DIY projects, like new deck builds, are so popular.

Using a cable railing system gives homeowners the safety they require without sacrificing their view. Although there are many options, some manufacturers provide entire assembly kits for installing cable railing, reducing effort and guesswork; saving both time and mistakes.

However, DIYers and professionals alike run into the problem of taking the cable railing around corners and on stairs. RailFX cable railing systems provide the components necessary to make these transitions easier to install, however questions might arise during your project.

What should I plan for during my cable railing installation? (or “Where should I start?”)

Start by plotting out the railing system, using a bird’s-eye view to draw out the project. You’ll want to plan out: 

  • All post locations
  • Railing lengths
  • Railing height
  • Post configuration (single or double) at corners
  • Locations of stairs and corners
  • Post height
  • Material (wood, steel, aluminum, composite sleeve)
  • Cable diameter (1/8” or 3/16”)
  • Composite sleeve diameter (if you’re using composite sleeve)
wood deck with cable railing

Are any special tools needed?

The RailFX system was designed to eliminate the need for any special tools for a smoother installation. That’s why you’ll notice features like the pre-drilled posts, making cable threading through posts a much easier step, especially since all cable railing fasteners are included in the kit.

You might also have the following basic tools at the ready:

  • Angle Finder
  • Cut Off Wheel
  • Cable Release Key
  • Cordless Impact Drill
  • 9/16 Socket with adapter
  • Ear Plugs
  • Fine File
  • Level
  • Masking Tape
  • Pen/Pencil
  • Power Miter Saw with 80 tooth carbide blade
  • Razor Knife
  • Roto Hammer with concrete drill bit
  • String / Laser
  • Tape Measurer
  • Vice Grips / Cable Gripping Pliers
  • #2 Phillips bit
  • #2 Square drive bit
cable railing on wood post

What’s the difference between installation on wood and metal posts?

For wood posts, you’ll need to keep the post from bending when the cables are tensioned, so a minimum 4×4 (3½”-square) post is required. The top rail should be reinforced with support, like a 2×4. Note the end posts should be checked and securely mounted to the deck before the cables are tensioned. A bottom rail can also help to distribute tensioning force away from the bottom of the post, but it isn’t required.

RailFX offers kits that are designed for aluminum posts with 1½ x 1½ inch square and 2 x 2 inch square tubing (note the posts are not included in the kit). End posts should be a minimum 1/4” thick wall to handle the load when the cables are tensioned; intermediates can be 1/8”. A top rail is essential for the system’s structural integrity. For aluminum, your end posts should be reinforced. And depending on your design aesthetic, you might want to consider a bottom rail for an added touch.

What should I know about the post configurations, especially at transitions like corners or stairs?

You’re provided with pre-drilled posts when you order the RailFX cable railing system. If you’re using existing posts, installers will need to drill holes as indicated by the installation instructions. The size of the holes will vary depending on the fitting or cable size. Another factor is if the fittings will terminate or if the cable will be threaded through the corner post for cable run continuation. For other posts in the system, the holes may only need to be one size. Unlike some competitors’ railing systems, which ask you to drill as many as 4 to 5 holes sizes in a particular post, RailFX drills the necessary hole in the post for you.  However, be sure to verify the number of different hole sizes needed for the kit you purchase.

When deciding the post configuration for corners, there are a couple options. Based on your design aesthetics and post material, you can choose to include either one or two posts in the corner. If you are using 4” x 4” wood posts, one post in the corner is sufficient. The RailFX aluminum system provides the option to utilize one or two posts in a corner.  

Cable transitions for stairs may seem complicated however RailFX  makes it easy by breaking it down step-by-step in their installation instructions. If the project calls for wood posts, it’s recommended to purchase the optional Post Protector Tubes. These will prevent the cable from slicing the wood when threading it through and exiting the post on an angle.

Railing inspiration

Is cable railing easy to maintain?

Your cable railing might accumulate pollen or some oxidation at the surface, and natural weathering is normal. The RailFX system is popular because it’s low maintenance, needing only an occasional cleaning with a simple soap and water solution.

Does the cable railing system come with a warranty?

The RailFX system, cable and fittings are all covered by a 10-year warranty.

How much can I expect to pay for the RailFX cable railing system?

Contractors, architects and DIYers alike appreciate the quick turn-around time on quotes the RailFX service team provides so you can plan your project’s budget easily. No one wants to wait weeks to hear back on a quote, RailFX customers can complete a quote for their project and expect to hear back within 48 hours.

Choosing the Best Cable Railing System for Your Design

By choosing a cable railing system from RailFX, installers are guaranteed a smoother project. And with a 2 week lead time from order to delivery, plus durable packaging for shipment, you can help to ensure your job gets done correctly and on schedule.

Have questions about your next installation? Contact us here.

Cable railing is a nice contemporary option for both indoor and outdoor spaces. They’re low maintenance, durable and offer limited visual distraction. They ensure that homeowners can enjoy a clear view from their outdoor living space or make a room feel larger.  Pickets or other visual hindrance options are used for staircases, instead of using rods. 

Like all railings, cable railing systems perform a critical safety function. They must meet rigorous international, national and state building codes. Homeowners can rest assured that they and their visitors are safe when cable railings are installed in accordance with these standards. 

One key factors in properly installing a new cable railing system is spacing. The cables are installed with high tension in order to avoid sagging and stretching. In a cable railing system, contractors are typically referring to:

  • Cable spacing
  • Post spacing

Proper Cable Spacing

cable railings by the ocean

Whether cables are installed vertically or horizontally, the spacing between them is defined by “sphere rules.” Fittings and cable in runs must be spaced and tightened so a four-inch sphere can’t pass between the open area between each cable.

Since properly installed railings may have some deflection, codes and best practices typically recommend runs be installed with 3 ⅛” spaces between them. To simplify, many contractors will estimate the number of cable runs using the following equation:

Number of runs = (Height in inches from floor to the bottom of the top rail ÷ 3) – 1

Subtracting one in this calculation means the railing system will not have a cable run along the floor or deck surface. Using this calculation, the runs will meet the maximum sphere rule requirements.


Cable Railing Diagram

The exception to the four-inch sphere rule is cable railings used for staircases. Here, the lowest cable railing can be six inches from the ninety-degree corner at the back of an individual step. However, the cable still needs to be four inches from the front edge of the step.

After all the cables have been installed, tension the cable to a minimum of 225 lbs with an open-end wrench. Hold the cable with cable grip locking pliers to prevent it from rotating. Make sure you tension all cables in sequence. Begin with the center cables, moving up and down toward the top and bottom.

Proper Post Spacing

Cable railing

The other important component of cable railing installation is the spacing between posts. Wood, steel, aluminum or composite posts can be used in a cable railing system. They must be securely mounted to ensure they won’t bend when the pressure of over 200 lbs is applied by the high-tension of cables.

Every type of post material (wood, aluminum, composite or steel) has its own suggested thickness. This is true for both intermediate and corner posts. The greatest tension will be on end and corner posts.

Unless you are using additional support, the spacing between most posts should not be more than four feet apart. This ensures the cables still meet the 4” sphere rules. However, RailFX’s posts and cables are rated to be five feet apart, letting you use less intermediate posts in your design.

If a design calls for wider post spacing, there are two ways to accommodate this. To account for deflection, for every foot over three to four feet (depending on the manufacturer) between posts, cables must be moved ¼” closer. Using this calculation, posts five feet apart need cable runs with no more than 2 ⅞” of spacing between them.

Alternatively, cable railing posts can be spaced farther apart if they are reinforced with post stiffeners. RailFX cable railings are approved in 35 states to be spaced five feet apart with these stiffeners.

Build the Perfecting Railing

Together, the right combination of cable runs, posts and top rails can create an attractive and safe railing system.  They are a perfect finishing touch on a deck or staircase. Properly installed cable railings keep homeowners safe while letting them enjoy their view to its fullest potential.

For more information on RailFX cable railing systems, visit the RailFX website.