Metal Stair Stringers Aren’t Worth the Time

Recently, I embarked on a project to replace the stair stringers on my deck. In California, treated wood isn’t what it used to be. As a result, it’s often rotted and failing after about 10 years. Nearly everything California does to “save the environment” seems to come with unintended consequences. Since modern treated lumber lacks durability, some insurance companies no longer cover homes with wood stair stringers due to their higher risk of failure and resulting claims.

After researching the issue and realizing my own stringers were deteriorating, I decided to invest in steel stringers instead. I assumed they would be a better, more permanent solution. Unfortunately, the experience left much to be desired.

At first glance, the steel stringers I purchased from a well-known manufacturer looked solid, with good welds and a sturdy design. Since I needed to build 12 steps, I ordered a kit that came with two 6-step sections, which are meant to be bolted together. That part seemed simple enough. After drilling five holes and attaching the joiner brackets, I had my metal stringers assembled and ready for installation.

That’s where the real work began.

Once bolted together, I noticed the two sections weren’t perfectly aligned. In fact, when placed side by side, the step heights were off by a quarter of an inch. With a 42-inch wide staircase requiring three stringers, this misalignment became a real problem. Each stringer had to be mounted differently to compensate for the height discrepancies. In my case, that meant using metal shims at the base of one stringer and adjusting the upper mounts for the other two. These modifications added several hours of extra work just to ensure the stair treads would be level across the width of the stairs.

Installing the stair treads was another ordeal. With traditional wood stringers, you simply screw the treads in place. With steel stringers, each tread must be marked from underneath to locate where to drill holes for the carriage bolts. Every step required 12 bolts—yes, 12 per stair. You might think you could create a template and drill all the treads at once, but think again. Due to sloppy manufacturing, the pre-drilled 5/16” holes were inconsistent, and the alignment varied from tread to tread. This meant every step had to be measured, marked, and drilled individually.

Now imagine doing all of that while lying upside down underneath the stairs to mark the bottom ones near the ground. It’s no wonder that contractors give metal stringers low ratings. Several professionals have noted it takes about two full days to install 12 stairs. I’m three days in, and I’m still not finished.

Sure, metal stringers are strong and long-lasting. If you’re planning to stay in your home for the rest of your life, they’re a smart investment—you won’t have to rebuild the stairs every 7–10 years. But if your foundation or base isn’t perfectly level (which is common if you have sloped concrete for water drainage), you’re going to face problems getting everything to line up correctly.

Another major consideration is the cost. I paid $500 for three steel stringers. Add another $150 for carriage bolts, nuts, and washers. Then include the cost of concrete anchors, additional support framing, railing, and stair treads, and you’re well over $1,200—and that’s using wood for the treads. If you opt for composite materials like Trex, tack on another $300. In total, that’s $1,500 for a 12-step staircase. Yes, it will last a lifetime, but if you’re like most Americans who move every 5–7 years, it may not be worth it. Wood stringers might make more sense.

Then there’s the issue of insurance. In my case, I’m paying $9,000 a year just to insure my home 30 miles west of South Lake Tahoe—and that’s with a high deductible. Insurance companies are doing everything they can to avoid writing policies in California. If they inspect your home, be prepared to spend thousands making repairs for anything they decide is uninsurable. Decks and roofs are major targets. Even a single crack in an asphalt shingle at the ridge peak can render your home uninsurable.

So, if you’re planning to replace or build new stairs, you’ll need to weigh cost, time, and durability. Contracting the job out with metal stringers might cost around $5,000, versus $3,000 for a wood version. If you’re doing it yourself, estimate $1,500 for metal vs. $700 for wood. Be prepared for unexpected challenges and a physically demanding installation.

Would I do it again? Yes, because I want the job done once and done right. But now I understand just how much work and frustration is involved. For many, it may not be worth it—so think carefully before diving into a project like this.