How to Install Cable Railing

First-time aluminum cable railing system installation and results.

Even though I’ve been a remodeler and deck builder for a few decades, I’m still frequently asked to build and install items I’ve never built or installed before. When building things for a particular client—a deck detail, a new opening for a kitchen remodel, site-made trim, or a privacy screen —I must suss out how the continuous load path combines with drywall and trim details that look like they grew there. 

For non-commodity items I’ve never installed before, the intellectual Jenga often depends on the manufacturer’s instructions but with nerve-wracking “what ifs.” I can’t just run out to the lumberyard and get more of these items, as I can with wood. 

I often feel this way after the casing is off the opening and I’m unboxing a $5,000 entry door that has to fit! RIGHT NOW!

That was how I felt about installing my first cable railing system on a deck remodel. On this install, it turns out my fears were unfounded, and the RailFX cable railing system I used went in with nary a hitch. (However, I still ordered an extra post, just to play it extra safe.) Here are four areas to pay close attention to when doing this yourself. 

Deck Framing and Layout

While there are joist- and bracket-mounted posts, we chose deck-mounted posts for a clean look. Step 1 involves preparing the deck frame for the railing posts with blocking between the framing at the band joists. Later, the posts will be secured to the deck through this wood blocking.

My layout principle is what I call “layout by centers.” I don’t know if everybody does it like this but laying out by centers ensures my posts are evenly spaced and the arithmetic is simple. 

The gist is to measure to the center of the front band joist. Then, measure to the center of those openings, left and right. Then, measure the centers of those openings until the openings are 60 inches or less, as that’s the RailFX specification.

In those marked locations, fasten two blocks on the flat between the joists. If the post layout lands on or near a joist, I put blocks in each bay so I’m sure the fasteners used later will bite. Repeat for left and right bands. Then, the decking can go on.

Step 1 of a cable railing install involves preparing the deck frame for the railing posts with blocking between the framing at the band joists. Later, the posts will be secured to the deck through this wood blocking. Credit: Mark and Theresa Clement, MyFixitUpLife

Post Layout

After the decking is installed, I do an accurate post layout on the decking, measuring to the center of the post locations and just making a tick mark on the deck. On this treated Southern Pine deck, a pencil worked. 

After the decking is installed, I do an accurate post layout on the decking, measuring to the center of the post locations and just making a tick mark on the deck. On this treated Southern Pine deck, a pencil worked. 

Were this a composite deck—especially a dark one where pencil lines are hard to see—I’d use Gorilla Clear Tape (Side note: This stuff is great. It sticks like crazy and peels off easily) on the decking, then tap the tape with a Sharpie. 

With the post locations marked, it’s time to install the railing posts. The corner posts are first. On this deck, I used two posts in each corner, but the RailFX cable railing system can be done with one. Transition posts kept our cable runs much shorter. 

RailFX sends ~⅜-inch x 6-inch lag screws. These accept Fedora washers (I made that name up based on their shape) that go in with the brim up. They accept decorative caps later that cover the hardware and create a streamlined appearance. The included lags set just fine, however, if you have a favorite structural screw, these work as well.

For shimming, RailFX calls for composite shims. We had to shim a few, but mainly we used the impact driver, lags, and the minor compression of the wood to plumb the posts up.  

Next, we ran mason’s line between the corner posts as a guide for the field posts, orienting it such that the line ran on the outside face of the posts. Many builders use lark’s head and fiddle string knots for this. I use a bowline knot, trucker’s hitch, and a half hitch to cinch it. Then we set the field posts.

Here, Theresa and I install the posts. They came pre-drilled and with all fasteners included. The posts are made from aluminum and the fittings and cable are made from 316 marine grade stainless steel that boasts a recycled content of 65%, including 25% post-consumer material. It offers a much longer service life than wood, making it an ultra-sustainable decking solution. Credit: Mark and Theresa Clement, MyFixitUpLife

Threading the Cable 

Threading the cable is simple. Take care not to walk on the cable as you lay it out on the decking. There’s a little Jenga to play, getting it to pass through the lower holes, because it’s hard to see. We found that threading loosely from the bottom up was easiest for seeing the holes. 

It’s important not to tighten them from the bottom up, so just loose fit them until all the cables are in. 

Cables are mounted with Invisiware Receiver Fittings on one end, prior to threading them through the post (holes). At the bitter end, a Push-Lock fitting is slid on and the cable is hand tensioned. 

The Push-Lock fitting works like a zip tie. Once the cable is inserted into the fitting, it locks into place. The Pull-Lock fittings on one end, prior to threading them through the pre-drilled post holes. At the bitter end, another Pull-Lock fitting is slid on and the cable is hand tensioned. 

The Pull-Lock fitting works like a zip tie. Once the cable is inserted into the fitting, it locks into place. A cable release key can be used to remove the cable from the Push- and Pull-Lock during installation and cable-trimming process. 

The cable ends are then cut with a Dremel rotary tool and then capped to protect the cut cable.

The posts came pre-drilled, which made the system easier and quicker to install. Theresa threads the cables from bottom to top, waiting to tighten them with an Allen wrench until after all the cables are in place, which a homeowner can use for future tensioning needs. Credit: Mark and Theresa Clement, MyFixitUpLife

Finishing Touches

The Pull-Lock is installed at one end of the run and an Invisiware receiver is installed through the other end of the cable run and acts as the tensioning fitting. The Invisiware receiver is concealed and hidden inside the post for a seamless appearance that the homeowner loves.

The RailFX system we installed was capped with the RFX400 top rail and we added a wood drink rail on top. The RailFX cap is a metal hat channel of sorts that mounts over the posts. 

Since nothing is perfectly flat as built, the post tops aren’t laser straight and it took a little tinkering to get it seated. Once it snaps into place it’s satisfying. Double check from below that it seats on all posts. 

The wood top is screwed from underneath the cap. Free advice: Pre-drill the pilot holes in the RailFX cap prior to installing it rather than upside down through the cable. The RailFX system offers a 20’ top rail length with very few rail splices, which adds to the seamless look of the railing. Credit: Mark and Theresa Clement, MyFixitUpLife

The wood top cap is screwed from underneath the RailFX400 top rail. Here, Future Mark would tell Past Mark to pre-drill the pilot holes in the RailFX400 top rail prior to installing it rather than upside down through the cable. 

The wood drink rail is pressure treated to match the decking. To keep miters from opening as the wood dries (they always open), I made a stepped joint that I froze in place with four 4-inch coated Spax trim drive screws. When the wood moves, it’ll move uniformly, and the joint will remain looking good.

The RailFX system includes low-profile, hidden fasteners, which create a sleek look to the finished rail system. Here, Theresa easily snaps the caps on the screw heads. Credit: Mark and Theresa Clement, MyFixitUpLife

The customer is thrilled with the deck and rails. The look matches the warm minimalist mojo of her home and gives her the clear lines of sight past the deck area she desired, allowing her to savor sunsets at the end of each day. And we won this game of cable railing system Jenga. 

The incredible transformation of an aged deck into a modern outdoor oasis is complete. The homeowner is thrilled with the look of the railing and deck design and is especially excited with the view-through aspect of the cable railings. Now she can enjoy sunsets and views of the woods much more easily than she was able to through her old clunky (and deteriorating) wood rails. Credit: Mark and Theresa Clement, MyFixitUpLife