Cees and Zees: Essential Red Iron Secondary Framing for Steel Buildings

Secondary framing, specifically Cees and Zees, provides the structural skeleton for commercial, industrial, and agricultural steel buildings. These red iron components bridge the gap between the primary mainframe and the exterior metal panels to ensure proper load distribution. Pioneer Metals manufactures high-strength secondary structurals factory-direct in Jackson, GA, to meet precise architectural specifications.

⚠️ Disclaimer: This guide provides general technical information regarding structural steel components. Framing requirements, including member size and spacing, must be determined by a licensed structural engineer based on local wind, snow, and seismic loads. Pioneer Metals is a manufacturer and does not provide engineering or design certification services.

What are Cees and Zees?

Cees and Zees are secondary structural members cold-formed from high-strength red iron steel to support roof and wall panels. Named for their specific profiles, these members act as purlins (roof support) or girts (wall support).

  • Cee Sections: Formed in the shape of the letter “C,” these are typically used for eave struts or headers where a flat mounting surface is required on one side.
  • Zee Sections: Formed in the shape of the letter “Z,” these profiles allow for lapping at the frames, which creates a continuous beam effect for higher load capacity.
  • Eave Struts: These specialized profiles serve as a transition point where the sidewall girt and roof purlin intersect to support both the roof and wall systems.

For available sizes and gauge options, visit our Red Iron Product page.

The Structural Role of Secondary Framing

Secondary framing creates a “structure within a structure.” Much like the floor joists or rafters in a wooden building, red iron purlins and girts perform three critical functions:

  • Load Distribution: They transfer weight from the roof and wall surfaces directly to the primary steel frames and the foundation.
  • Lateral Bracing: These members provide lateral support to the primary frame’s compression flanges, increasing the total load capacity of the building.
  • Diaphragm Strength: When fastened to metal panels, the framing creates a rigid horizontal diaphragm that resists longitudinal forces like high winds and seismic activity.

Material Science: Cold-Formed vs. Hot-Rolled Steel

Understanding the manufacturing process is vital for precision applications. Most Cees and Zees are cold-formed, which differs significantly from heavy hot-rolled structural steel.

  • Cold-Formed Steel: This process involves bending steel at room temperature to achieve exact dimensions and high strength-to-weight ratios. It is the industry standard for secondary framing due to its precision.
  • Hot-Rolled Steel: Pressed at temperatures exceeding 1,700°F, this steel is more pliable during manufacturing but less dimensionally precise after cooling. It is typically reserved for primary heavy-gauge columns and beams.

What Happens If Secondary Framing is Mismanaged?

Improper selection or installation of purlins and girts leads to localized structural instability. Engineers must account for several risk factors:

  • Distortional Buckling: This occurs when a portion of the compression flange or web shifts from its initial position under a heavy load.
  • Lateral Displacement: Insufficient bracing can cause the members to twist or shift, compromising the seal of the metal panels.
  • Environmental Degradation: While red iron is naturally resistant to fire and termites, unsealed or scratched members in high-moisture environments can develop surface rust if the primer is compromised.

Check our Resources for technical specs on metal building maintenance and protection.

The Pioneer Metals Advantage

Pioneer Metals eliminates the long lead times and high markups associated with retail steel distributors. We prioritize precision and speed for the Southeast Georgia construction market.

  • Custom Lengths: We manufacture Cees and Zees to your specific project dimensions, including lengths exceeding 30 feet.
  • Factory-Direct Pricing: Sourcing directly from our Jackson, GA facility reduces material costs by removing the middleman.
  • High-Strength Red Iron: Our secondary structurals are engineered for longevity, offering superior resistance to pests, fire, and structural rot.

Secure Your Primary Frame

The integrity of your steel building depends on the quality of its secondary support. Contact Pioneer Metals to receive a quote on precision-manufactured Cees and Zees for your next project. Request a Red Iron quote.