Facts on Risers

Height

• The riser is installed to the vertical part of the stringer. The stringer is the large piece of wood with teeth cut into it onto which the steps and risers are installed. If the riser is too high, the stairs can be difficult to climb. The ideal height for a riser ranges between 8 inches and 8 1/4 inches, according to the U.S. Inspect website. The Best Deck Site offers a quick method for determining the right height for a riser: The sum of two risers and a stairway run should be approximately 24 inches. A run is the distance from riser to riser on a step. If a step has a run of 8 inches, then the two risers can be 8 inches each to make a total of 24 inches.

Design Considerations

• The design for the risers for a flight of stairs needs to have a ratio that allows for a comfortable stairway. If the riser is too high, people will trip as they attempt to use the stairs. This is especially dangerous for young children who may be running up and down the steps and elderly people who have difficulty using the stairs. If the riser is too low, your stairway will be extremely long and shallow.

Human Error

• Measuring and cutting stair risers is often not an exact science. Stringers can sometimes have riser mounts that are off slightly from one step to the next. According to the U.S. Inspect website, the height of all the risers in a stairway should be within 1/2 inch of each other to allow safe and comfortable use of the stairs.

Nosing

• The run of the step is the distance from the back riser of that step to the riser on the step below it. The remaining part of the step that hangs over the riser is referred to as the nosing of the step. Nosing is done primarily to enhance the design look of the stairs and is not a mandatory part of a stairway design.