The Lapeyre Alternating Tread Stair

The Lapeyre Alternating Tread Stair offers a cost­-effective, secure alternative to vertical ladders and steep stairs.

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Reach New Heights

From NASA to Miller Brewing, industry leaders choose the Lapeyre Alternating Tread Stair for its improved ergonomics and safety and its efficient design. This innovative alternative to steep stairways and ladders is ideal for factories and in­-plant offices as well as ships and offshore vessels.

Eliminate hazardous ladders and safely access tight spaces such as:

  • Mezzanines
  • Rooftops or Roof Hatches
  • Equipment access
  • Machinery Conveyors
  • Crossover Systems
  • Storage and Walk Platforms
  • Catwalks
  • Pits
  • Storage tanks
Wood Pizza and Taphouse

ATS Case Study: Wood Pizza and Taphouse


Employees needed safe access to a loft storage area, but space was a commodity in this icehouse turned taphouse in New Orleans' Central Business District.


Lapeyre's Alternating Tread Stairs were installed in order to provide the access needed without compromising the limited space with a large staircase footprint.


After a couple of weeks of practice, employees got the hang of the unique tread of the ATS system and were able to access storage quickly and easily.

How the Alternating Tread Stair Works

Benefits of ATS Diagram

Imagine walking down (or up) a conventional stair. Each foot normally uses only about half of each tread, stepping out and over the unused section (shaded red).


On a steeper stair or ladder, the unused half tread becomes an obstacle, significantly reducing the usable tread depth of the tread directly below. As the angle increases, the problem becomes worse.


In contrast, the Lapeyre stair removes the unused half of each tread, allowing the foot to reach the next tread in a straight, direct line, providing more usable tread depth.

Stair Design Details

The Alternating Tread Stair has a flexible design that can be customized to meet the unique needs of individual projects.

Steel Alternating Tread Stair Aluminum Alternating Tread Stair
The STEEL alternating tread stair The ALUMINUM alternating tread stair
Utilizes a three stringer design with alternating treads that weld to the stringers. Utilizes a central stringer with curved treads that weld directly to the handrail.
Includes handrails that are bolted in place during the installation process. Ideal for outdoor areas where corrosion and rust are a concern, as well as rooftop applications where weight is a major consideration.
Available in carbon steel with choice of finish or stainless steel with natural finish. Shipped as one complete welded unit, ready to bolt into place.
ANGLES 56° 68° 68°
HEIGHTS, Custom built to exact vertical height
Standard Handrail 36" to 240" 42" to 240" 24" to 216"
Optional Handrail 48" to 240" 48" to 240" 55" to 216"
Flush Handrail 48" to 240" 48" to 240"
Carbon Steel
  • Hot Dip Galvanized
  • Powder Coat
Natural Finish ONLY
  • Landings, Treadings and Foot Castings:
    • Aluminum Alloy F356F
  • Guards/Handrails:
    • Aluminum Alloy 6063-T4
  • Central Stringer:
    • Aluminum Alloy 6063-T52
Stainless Steel Natural Finish ONLY
Standard Handrail Extends 42" above the top landing of the stair and is used on most stair applications. Extends 42" above the top landing of the stair.
Optional Handrail This shortened rail extends 5­-3/4" above the top landing of the stair and is designed for use within a roof hatch or a hatch with a standard 12” curb. This is the most commonly used option for stairs going through an access hatch. Designed for roof hatch applications, this rail extends 3­-3/4" above the top landing.
Flush Handrail Rail terminates flush with the top landing of the stair. This rail is the least common and is used inside of access hatches with little to no curb.
All rails are close fitting with a 20” inside width and 23” outside width.
Flush Handrails Standard Handrail Optional Handrail
42" 5-3/4" Steel 0" - Terminates at
top Landing
42" 3-3/4" Steel
20" 20" 20" 20" 20"
23" 23" 23" 23" 23"
VIEW DRAWINGS 56° 68° 56° 68° 56° 68° 68° 68°

Benefits of alternating tread stairs:

  • A) Accommodate hard-to-reach spaces and steep descents.
  • B) Forward-facing design to increase comfort of steep incline descent.
  • C) Smaller footprint that a traditional stair.
  • D) Cushioned central stringer eliminates the possibility of hitting the nosing of a tread to reduce the risk of trips and falls.
Stair Features

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