What are the minimum and maximum stair dimensions (rise & run) for the Ladder-Aide?

The Ladder-Aide Pro can be used on any stairs that meet the National Building code of Canada. 
The original Ladder-Aide requires a slightly taller minimum rise.

Minimum step dimensions

  • Minimum rise height 
    • LAPro: 4.921"
    • LA1: 5.125"
  • Minimum tread depth: 8.268"

Maximum step dimensions

  • Maximum rise height: 7.875"
  • Maximum tread depth: 13.975"

What do "riser height" / "rise height" and "tread depth" mean?

Stair " rise height" is the vertical height or distance between the surface of two stair treads (what you actually step on). You should measure riser heights vertically, between the leading edges of two consecutive steps.

Stair " tread depth" is measured from the front edge of the step to the back of the step being measured. 

The general rule in the United States is a 7" rise and 11" tread depth.