I had a client a while back with a problem. He'd installed cable railing, and now every few months, the cables had to be tightened because they would start to sag. On top of that, his wooden end posts were getting pulled out of shape by the cable. Unfortunately, both of these problems are common issues I see when someone tries to DIY a cable railing system for their deck or porch. Cable railing is great to look at, but it's not easy to install. That's especially true if you want to install use cable along with wood posts.

The big issue with cable railings is their tension. Most safety standards state that the cables must be tense enough to prevent a 4-inch ball from passing through. That means the cables need to be extremely taught. It leaves little room for slack and a lot of room for error. The difficulty jumps up a level when you're trying to use cable in conjunction with wood, as wood is more likely to bend and crack than materials like metal. My suggestion if you're considering wood and cable, and are tempted to DIY, is to choose a good compromise. A cable railing kit for wood posts is easy enough to install that you don't absolutely need a pro, but is basically pre-assembled and designed to work with weaker materials like wood in a friendly way.

Cable Railing Kits for Wood Posts: Qualities to Look for

Cable railings have a lot of benefits, specifically in their durability and their low rail profile, making them a good choice when you want a railing that doesn't block the view. However, because of their strength, you must have a powerful framing system to support them. Otherwise, the tension of those cables will pull the frame out of place. Then the cables can droop and the whole railing will become unstable, which is not what you want from a structure that's supposed to protect people from falls. Using a cable railing system with wood posts increases the risk. A few ways to ensure your cable railing stays sturdy:

• Choose vertical over horizontal: While there aren’t a lot of vertical cable railing kits out there (cable railing systems usually have the cables running horizontally), they are possible to find, and because the cables run up and down rather than side to side, they take much of the stress off of the railing’s posts. These systems work a bit more like a picket-style railing system, with the tension being more evenly spaced out along the rails. Some vertical cable panels also come with top and bottom rails, which is the perfect way to take pressure off the wood parts of your railing.
• Use hardwood or pressure-treated wood for posts: Hardwood and pressure-treated wood posts will have the durability needed to prevent bending, breaking, and splintering over time, especially if you don’t go with a cable railing kit. Softwoods like untreated cedar or pine just aren’t appropriate for this type of system.
• Evenly space the cable runs: If you’re doing a horizontal installation, you need to ensure your cables are evenly spaced to prevent one area from having more tension on it than the other. Several cables clustered close together with others far apart will cause more tension in the clustered area, resulting in bowing of the post. Even being a few centimeters off can create this issue, so measure and measure again before installing the cables. Or choose a cable railing kit that comes in pre-assembled panels that don’t require drilling and removes any guesswork.
• Use powerful post bases: A strong post base can help take some of the tension off the post by anchoring it firmly to the surface of your deck or balcony. And make sure you choose post bases designed to work with pressure treated wood, so the chemicals in the wood don’t cause corrosion on your post bases and hardware.

You've probably figured out by now that cable railings can be a bit tricky, and that the materials you use and the design of the system you choose make a huge difference. In my opinion, the best option is to buy a kit designed to be compatible with different types of post materials, including wood. Cable railing systems for wood posts that come in panels take a lot of the worry out of installing your railing.

Not All Cable Railing Panels Are the Same

Cable railing panels are much easier to put in since they give you pre-drilled holes and have already been specifically engineered to resist the tension of the cables. You might assume that choosing a panel (rather than doing it yourself) would be the more expensive option. However, cable panel systems often prove to be the most cost-conscious method, since you're just making one purchase - instead of cables, post rails, and hardware separately. When it comes to choosing a panel system look for ones that:

• Are designed to work with wood: The panel railing system should state specifically what posts it’s designed to work with. Usually, these can be purchased as part of the overall set. Regardless, don’t mix and match unless the installation instructions indicate you can. In addition, when cables are installed horizontally, the end posts should be at least 4x6 to ensure they’re strong enough to hold the tension.
• Come with a tension gauge: While the panel system comes pre-assembled, you’ll need to tighten the cables yourself. This is a pretty easy process, but it’s also easy to overtighten them. A tension gauge will tell you how tight the cables are while your specific panel instructions will give you the right tension to aim for.
• Work with your climate: When looking for your cable panel system, choose a steel cable railing system that uses marine-grade stainless steel. This is the most durable, high-quality type of cable, and it can stand up to almost weather without corroding. If you’re looking for durability, you may also want to make sure your cable cables run vertically as opposed to horizontally, since vertical systems spread the tension is spread out, and for this reason often last longer.

Like I told that client long ago, if your cables are sagging, you've already done it wrong. Moreover, it's going to be very difficult to reuse your wood posts if they're already bent out of shape. With that client, we went back to the drawing board and reinstalled his cable railing using vertical cable railing panels and new wood posts.

In that case, and others, I generally choose vertical cable railing system from Fortress Building Products because they’re easy to install, super durable, and made with high-quality materials like the marine-grade stainless steel I mentioned. Fortress® systems also meet a wide range of building code standards, including the International Code Council, the National Building Code of Canada and the International Residential Code. They’re an ideal option if you’re looking for cable railing kits for wooden posts that are durable, stylish, and easy to put together.