Evolution Steel Framing Part 2: Why To Consider Steel Stair Framing

Todd Dermody smiling.

"Welcome to our two-part framing series. In this second installment, Toby Bostwick, Fortress Building Products’ Vice President of Product and Brand, discusses the most common defects seen in deck stair framing systems and how to avoid them by utilizing better building materials."

- Todd Dermody


In part one of this framing series, we explored how homebuilding novices and building industry professionals alike have begun to shift towards steel deck framing systems for increased durability and stability. However, up until recently, these same systems weren’t available for connecting stair systems, leading to many of the issues that make stairs one of the most dangerous parts of an outdoor space today. In this blog post, we will discuss defects commonly seen in deck stair framing systems, and why builders are looking to steel for a safer option.

Why building inspectors lose sleep over deck stair framing systems

Stairs rank third in terms of number of personal injuries suffered on a deck (behind ledger detachment and guard failures). This rightfully makes them an area of intense scrutiny to home inspectors. When auditing an outdoor deck staircase for potential liabilities, home inspectors often find the same recurring culprits for potential problems, a few of which are listed below:

  • Miscalculations. It’s all too easy for builders to make a mistake when calculating the total number of steps needed, tread depth, riser height, the angle of the staircase, and the length of stringers.
  • One of the most serious deck stair defects is a poor connection between the stringers and the deck. Failure at this important connection is common, particularly when the stringers have been nailed to the framing, because nails are subject to withdrawal.
  • Inconsistent rise and run. This point needs to be sung again and again because risers or treads that vary more than 3⁄8 inch between any two risers or treads creates a fall hazard. Humans in general become accustomed to a certain feel when using stairs, so any variation from the norm can cause someone to lose their balance and fall.
  • Damaged, decayed or broken wood framing will result in a weakened stair foundation. The stairs may also start to sink or settle, making the structure unstable and difficult to walk on.
Steel deck stair framing on an in-progress deck.

Why steel deck stair framing can alleviate these concerns

With innovative steel products on the market, deck builders now have the ability to extend the same benefits of steel deck framing to stair framing projects, subsequently addressing the problems listed above. Preassembled steel stair framing systems will:

  • Eliminate guesswork when measuring.
  • Minimize use of excessive stringers (Fortress Evolution step stringers offer a means to avoid miscalculations, and they can still be tailored to meet the builder’s needs).
  • Eliminate the need for nails.
  • The Evolution steel deck stair system can accommodate virtually any rise and run—eliminating variances in riser heights or tread depths.

Another advantage worth highlighting is that similar to steel deck framing, steel stair framing is not subject to wood’s “living” nature. Lumber’s varying moisture content means variation in board sizes where steel components are consistent in size. Additionally, steel stair framing doesn’t absorb moisture or warp with changes in temperature. Therefore, it’s able to remain much more dimensionally stable and equipped to handle years of heavy use when compared to wood.

Considering building with a steel stair frame? Fortress Building Products has engineered steel framing and stair components that come ready-to-assemble, saving DIYers and professional builders valuable time and material costs.