Aluminum Alternating Tread Stair

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The aluminum alternating tread stair:

  • Utilizes a central stringer with curved treads that weld directly to the handrail
  • Ideal for outdoor areas where corrosion and rust are a concern, as well as rooftop applications where weight is a major consideration.
  • Shipped as one complete welded unit, ready to bolt into place.

Stair Design Details

Table 1: Aluminum Alternating Tread Stair Design Details
Material Aluminum
Stair Finishes Natural finish only
Landings, Treads and Foot Castings: Aluminum alloy F356F
Guards/Handrails: Aluminum Alloy 6063-T4
Central Stringer: Aluminum Alloy 6063-T52
Angles 68°
Heights Custom height built to exact vertical height
Standard Rails:
 24" to 216"

Optional Rails:
 55" to 216"

Handrail Options

  • Standard handrail: extends 42” above the top landing of the stair
  • Optional handrail: designed for roof hatch applications, extends 3-3/4” above the top landing.


Table 2: Handrail tech specs
Configurations Rail Height --From Top Landing Inside Handrail Dimensions Outside Handrail Dimensions View Drawings
Standard Handrail(original rail) 42" 20" 23" View
Optional Handrail 3-3/4" Steel 20" 23" View