Understanding Truss Spacing and Why It Matters

Truss spacing — also called on-center (OC) spacing — determines how far apart the trusses or bows are along the length of your building. It sounds like a simple number, but it has a ripple effect across your entire material order.

Common Spacing Options

The most common spacing for metal carports and buildings is 5 feet on center. Other options include 4 feet for higher wind or snow loads, and sometimes 3 feet for extreme weather conditions. The tighter the spacing, the more steel goes into the building.

What Truss Spacing Affects

Trusses and Legs

Tighter spacing means more trusses and more legs on the truck. That's more steel, more connection points, and more installation time.

Anchors

Every leg needs an anchor — concrete, mobile home anchor, or rebar stake. More legs means more anchors to order and install.

Braces

Corner braces and top braces are installed at truss locations along open sidewalls. More trusses means more braces.

Screws and Hardware

Every truss requires fasteners for its connections. Adding even one extra truss means a noticeable increase in total hardware — and that number compounds across every connection point.

Horizontal Framing

The spaces between trusses (bays) get filled with horizontal framing. More trusses means more bays to frame, more material to cut, and more fasteners to install.

End Wall Uprights

End wall uprights follow the same spacing pattern. Changing the truss spacing changes how many uprights you need on the front and back walls.

The Trade-Off

Tighter spacing means a stronger building but more material and labor. For most standard installations, 5-foot OC meets typical wind and snow load requirements without over-engineering. High-wind zones or heavy snow areas may require tighter spacing as specified by an engineer.

Why This Matters for Your Cut List

Changing the truss spacing cascades through every section of the cut list — trusses, legs, anchors, braces, screws, framing, and end wall components all change at once. It's one of the hardest variables to adjust manually because it touches so many line items.