DIY Cable Railing – an easy deck upgrade!


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October 26, 2022
Zoe Hunt

As many DIY projects do, our DIY patio project quickly spiraled out of control. We decided to move the deck stairs and then realized while we were at it, we might as well replace the railing on the entire deck.

We opted for some clean, modern DIY cable railing to replace our existing vertical wood slats.

DIY cable railing on wood deck

And I’m so glad that we did. The cable deck railing opens up the space and doesn’t block the view. Because we opted for the thinnest cable, it looks almost invisible from certain angles! 

If you’re looking to update your deck railing and want something that is cost-effective and looks amazing, I can’t recommend DIY cable railing enough! 

We ended up making our own cable railing installation kit vs. buying one from a single company. It was significantly cheaper this way and lucky for you, we did the hard work of testing things out and seeing what worked and what didn’t.

Before we dive in, I just want to say that this DIY cable railing is significantly cheaper than installing glass, and depending on how large of an area you have, it can even be cheaper than installing wood! 

If you have a super small area to change the railings on, it might not be the most cost-effective solution because it does require an investment in some pretty uncommon tools. But if you’re working on a larger area, it can be a more budget-friendly deck rail option. 

Alright, let’s start DIYing! 

Recommended Tools: 

What You’ll Need: 

How to Install DIY Cable Railing


Everyone is going to have different starting points. Some people will be starting from scratch and need to install their own 4×4 posts to the deck. Some people will have existing railings that differ from ours. 

Some people will have the same railing style that we did. In that case, you can cut the caulk around the 2x2s and then pry them off. Fill any holes with Bondo, remove any excess caulk, and sand the posts down to prep them for paint or stain

Whatever spot you’re in, you want to end this step by having 4×4 posts secured to your deck and a handrail installed. Each of these items should be painted or stained. Yes, you’ll likely have a little touch-up paint at the end, but it’s nice to have the majority of it knocked out prior to installation. 

Free download wood sizing cheatsheet


Grab a scrap piece of wood and cut it down to be the same height as the distance between your deck and the handrail. 

Because of how our 4×4 posts were positioned on the deck, we marked 1.25” in from one edge of the board. We wanted our railings to be in line with the edge of the deck, which was 1.25” in from the side of the 4×4 post.

Next, decide how many cables you want. Double-check the code in your area, but we needed our railings to be close enough together that we could not push a 4” sphere through the cables. We decided to use 10 cables and place them each 3 1/16” apart. 

drilling through scrap wood to make a guide

We marked for each of the cables on our scrap wood guide and then drilled all the way through the guide using a drill bit that was large enough to fit a thin marker through.

We clamped the guide to each post and marked through each of the holes. 


Grab your drill guide and use the drill bit provided with the guide to drill into the posts at each of the points you marked. 

drilling into 4x4 deck posts using a drill guide

You’ll use the straight guides for around your deck and then you can use the 30-degree guide for stair posts. 

When drilling in center posts, you’ll connect the holes from either side so that there is a hole all the way through the center. 


Before adding the protective sleeves to the middle posts, poke something through the holes in the middle posts to remove any sawdust. The sawdust can get clogged in the hole and make it really difficult to get the wire through. 

Once cleared, place a protective sleeve into each side of the middle posts. 

For the two end posts, you have two different swage lag screws, one for the right side and one for the left side. The right side screws will screw in normally, but the left side screws will be screwed in by turning in the opposite direction, aka by flipping the drill into reverse. 

screwing swage lag screws into posts

You can tighten your drill around the end of the swage lag screws to quickly screw them in place. As you’re screwing them in, don’t tighten them all the way. Leave out a thread of two of the screw. We’ll finish screwing them in later to tighten the wire.


Measure the distance between your posts. If you have multiple posts, measure the distance all the way between the furthest posts and then cut your wire to be just slightly longer than that. 

Before installing the first cable, line the cable you just cut up with the edge of the remaining cable and mark where the cable ends with either a sharpie or some painter’s tape. 

This way you have a guide for your remaining cables if this one ends up being the right fit.

Fully install and test the first piece before cutting the rest. If you’re happy with the fit, cut all the remaining cables to the same length. If not, make adjustments to the next cable and try again until you’re happy with the length. 


Thread your cable through the protective sleeves and push it until the swage lag screw until it stops. Once it’s in as far as it can go, use the hydraulic hand crimper to crimp the lag screw in two different places. This will keep the cable in place. 

crimping cable into swage lag screw

Push the other end of the cable into the swage lag screw on the other side and crimp it in two places.


Note: there is a little wrench that comes with the lag screws, but it’s really cheaply made. Ours broke after installing about 4 of the railings. I’d highly recommend using locking pliers instead.

Grab your locking pliers and adjust them to fit tightly on the swage lag screws. 

twisting swage lag screw to tighten cable

Now if you have an extra set of hands and an extra set of pliers, that’ll speed along the process greatly. You need to turn the swage lag screws into the posts to tighten the wire. The right side will be turned clockwise and the left side will be turned counterclockwise. 

It’s really helpful to have two people turning at the same time to prevent the wire from twisting. If you only have one set of hands or one set of pliers, alternate between the two sides as you tighten it. 

The cable should feel tight, be there should still be some give to it. 

There you have it! Now you know how to install DIY cable railing. It’s going to give your deck a whole new look! 

before and after image of upgrading deck railing from vertical wood slats to modern cable railing

A few months later, we finally got around to replacing the railing on our screened porch as well! I love the look. The cables pop when looking back at the screened porch, but from the screened porch, they are almost invisible. Cable rails are definitely a great way to maximize your view!

cable railing on screened porch
cable railing from screened-in porch
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  1. Laura says:

    We want to do this for our deck, but we have some funky 30/60 degree angles and I’m not sure how to do the wire in the posts for those corners. Do you think this process will work or will I have to have separate posts and install the wire separately for each? I’d rather not do that but am unsure how to handle the angle otherwise.

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