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Module 4 of 10 240m 9 exam Qs

Curtain Wall & Storefront Systems

Curtain wall vs storefront, mullions, transoms, pressure plates, snap-on trim, weep holes, and thermal breaks.

  • Distinguish between curtain wall and storefront systems
  • Identify mullions, transoms, and pressure plate components
  • Explain the function of weep holes and drainage in glazing systems
  • Describe thermal break design and its importance for energy performance
  • Explain the pressure equalization principle for water management

Lesson 1

Curtain Wall Fundamentals

What Is a Curtain Wall?

A curtain wall is a non-structural exterior wall system that hangs from the building structure like a curtain. It carries only its own dead load and transfers wind loads back to the structural frame. The curtain wall does not support floor or roof loads.

Non-Structural
Carries Only Its Own Weight
Multi-Story
Spans Floor to Floor or Beyond
Stick or Unitized
Two Primary Construction Methods

Stick-Built vs Unitized

Stick-Built Curtain Wall

Assembly: Assembled piece by piece on-site

Components: Individual mullions, transoms, glass

Best for: Low to mid-rise, complex shapes

Speed: Slower installation

Unitized Curtain Wall

Assembly: Factory-assembled panels

Components: Complete framed units with glass

Best for: High-rise, repetitive facades

Speed: Faster installation

Anchoring Systems

Curtain walls are anchored to the building structure at each floor slab using anchor brackets. These brackets must accommodate:

  • Dead load - weight of the curtain wall
  • Wind load - positive and negative pressure
  • Building movement - sway, deflection, settlement
  • Thermal expansion - frame movement with temperature changes
Key Takeaway

A curtain wall is non-structural - it hangs from the building and transfers wind loads to the structure. Stick-built is assembled on-site; unitized uses factory-assembled panels. Anchors must accommodate dead load, wind, building movement, and thermal expansion.