When to Use Steel Instead of Wood Beams
We're a wood-first company. We default to wood because it works for 90% of residential applications. But we're not religious about it — there are clear situations where steel is the better call.
Steel Wins When...
- Spans exceed 36-40 feet: Engineered wood products have practical limits. A 24F-V4 glulam at 40' needs to be extremely deep. A W14×22 handles it comfortably.
- Depth is constrained: Steel has a much higher strength-to-depth ratio. When you can't afford a 16" beam but need 16" of capacity, a W10 or W12 steel section solves it.
- Point loads are extreme: Multi-story load stacking, transfer conditions, and heavy equipment loads can push wood beyond practical limits.
- Remodel constraints: Replacing a bearing wall in an existing structure often requires steel because the available depth and bearing conditions are fixed.
Wood Wins When...
- Spans are under 30 feet: Wood handles the vast majority of residential spans more economically than steel.
- The beam is exposed: Architectural glulam looks intentional. A painted steel beam in a living room looks like a compromise.
- Fire rating is a concern: Heavy timber has excellent fire performance — it chars predictably. Unprotected steel fails rapidly at high temperatures.
- The framing crew is wood-focused: Most residential framers are faster and more comfortable with wood connections than steel.
Cost Realities
Steel beam material cost is often comparable to engineered wood at equivalent spans. The cost difference shows up in connections, detailing, and labor. Steel requires welding or bolted connections, bearing plates, and sometimes fire protection — all of which add cost and coordination.
In a wood-framed building, a single steel beam also creates a thermal bridge that may require insulation detailing. This is often overlooked in the cost comparison.
The question isn't "wood or steel." It's "what does this specific condition require, and what's the simplest way to achieve it?"
See Where Wood Stops and Steel Starts
Our Beam Compare tool includes steel W-shapes alongside Glulam, LVL, PSL, and LSL. Enter your span and load — see exactly where the crossover happens.
Weighing steel vs wood for your project?
We can run the numbers and recommend the most cost-effective solution for your span and load.
Talk to Our Team