How far should the ladder rung extend beyond the riser? (2023)

Stairs are common in many building and landscaping designs. We've all climbed or scrambled down them, sat on them, and occasionally cursed when we stumbled up or down. The culprit of our embarrassment and comfort is often the overhang of the stairs. Too large or too small an overhang can affect the safe use of the ladders.

A stair step is at least 10 inches deep, measured horizontally from its front edge to the top of the step above. The stair tread overhang should extend past the riser edge or bottom tread by 3/4″ to 1-1/4″. No overhang is required for steps 11 inches or deeper.

In this article, we'll look at interior and deck stairs, identify their components, and explain profile overhang. We discuss where and if it is necessary and how much the tread should protrude if necessary. By the end of your reading you should have a better understanding of what a stair overhang is and should be.

What is a stair overhang?

When talking about anything, it helps to know what the different terms mean. Stairs consist of stringers, risers, steps, ledges or rounded and a landing. Climbing and running or walking are also common terms when it comes to stairs.

• Stringerare the two parallel diagonal elements that support the steps and risers. They can have a solid face or an open sawtooth design.
• elevatorsThey are the vertical or back section of any staircase. The riser is commonly closed with a board called a riser at the main internal staircase and opens onto the basement or deck staircase.
• stepsare the flat or horizontal part of the ladder where the feet make contact and must be at least 10 inches long, measured from their front edge to the front edge of the step above or below.
• NoseThey are the portion of the tread that protrudes and overhangs the riser (if present) and the step below 3/4" to 1-1/4". The leading edge can have a camber of 9/16 inch or less or a bevel of 1/2 inch or less. The nose hides the seam between the riser and tread and is for both aesthetics and safety.
• Bullnoseis a milled edge or bar that is attached to the front or side edges of the tread and gently rounds 180°.
• landingsThey are the flat horizontal space before the lowest step and after the highest stair. It is also a horizontal platform between sets of stair stringers.
• Liftis the total vertical distance between one floor and the next that a stair must traverse. It is also the distance from the top of one step to the top of the next, not to exceed 7-3/4".
• Runis the horizontal distance traveled by each step from riser to riser, or the depth of the step, which must be at least 10 inches. Total run is the horizontal distance or run between landings. It is the horizontal distance from the bottom edge of the stringer to the top back edge of the stringer.
• Isgois the horizontal distance from the front edge of the overhang of the tread to the front edge of the overhang of the following steps. It is the clear area to enter the tread and must be at least 10 inches. Overall length is the horizontal distance from the front edge of the bottom tread to the back edge of the top tread on a rail.

The overhang of the step is that portion of the tread that extends beyond the riser or riser line of the step directly below. It can be square, slightly rounded or beveled at the edges, or fully rounded or rounded. The overhang is also called the nose.

Does the staircase need an overhang?

Overhang has been used in many countries for centuries to widen a narrow tread or for aesthetic reasons. Provides more room for the toe box on the way up and for the heel on the way down. Modern studies have shown that when descending, the heel actually digs into the space under the overhang.

Similar studies have also shown that the overhang visually enhances the edge of the step and makes it safer. Based on such practices and studies, the building code identifies what is necessary.

The International Residential Code (IRC or ICC) sets minimum and/or maximum guidelines based on common building practices and research for safety purposes. It is reviewed and updated every 3 years.

The current release is version 2018 and Section R311.7 deals with stairs. Many countries and states adopt some or all of the IRC for their building codes, so a good starting point for any construction project is a review of your local building codes.

Per IRC 2018: Sections R311.7.5.2 and R311.7.5.3, the minimum tread depth is 10 inches, with no overhang. Stairs must have oneOverhang between 3/4″ to 1-1/4″to increase the depth of the step, making it better for descending while maintaining a 10" spacing for ascent. Steps 11 inches deep or more do not require an overhang.

How far should a stair protrude from the riser?

Determining how far a stair should protrude is part of the stair construction. Total Rise vs. Acceptable Rise of Individual Steps identifies the number of steps. The total traversal divided by the number of steps gives the depth of each step.

The building code specifies the minimum step of 10 inches and the maximum height of 7-3/4 inches; In addition, it identifies acceptable nasal protrusions. To increase the steepness of the stair and meet code requirements, the front edge of the step may protrude beyond the step below. However, it should be noted that excessive overhang is just as dangerous as undershoot.

Code Requirements for Ladder Rung Outriggers

Rungs and stair nosing are addressed in 2018 IRC Sections R311.7.5.2 and R311.7.5.3 respectively. The code identifies minimum and maximum requirements for both and is commonly adopted by many countries and states. It is recommended to check local regulations for requirements.

Tread depth must be at least 10 inches horizontally measured from the leading edge to the leading edge of the step above or below. Moldings should be a minimum of 3/4″ to a maximum of 1-1/4″. There is a maximum allowable deviation of 3/8 inch between the largest and smallest pitch dimension.

Standard rung outriggers

Every carpenter or stair builder has a preference when it comes to overhang depth, making the standard more of a range. Style and aesthetics also compete with safety, cost and comfort. 3/4 inch nose protrusions offer more safety than other dimensions according to some studies, but local building codes may dictate otherwise.

Acceptable IRC profile overhang requirements extend 3/4" to 1-1/4" beyond the face of the riser or riser line to ensure the spacing is 10 inches. The overhang increases foot placement space on the tread but does not change the tread depth or tread depth as defined by the IRC.

Manufactured stair treads are typically 11-1/4" or 11-1/2" deep to overhang the riser 1-1/4" or 1-1/2". The leading edge is often given a 1/2 inch radius to allow a 3/4 inch or 1 inch shallow extension beyond the face of the riser. Instead of tearing up the tread to conform to regulations, many joiners add a 5/8 inch bay or scroll down to the bottom of the nose and front of the riser.

Minimum overhang of the stair step

Stairs across the country and around the world vary in rise, tread depth, and rise. What was acceptable in the past may no longer be acceptable, and the reason is usually security. Steep steps with narrow steps have given way to wider steps and gentler slopes. In some cases, adding a nose was enough.

Stairs with a tread depth of 11 inches or more do not need to overhang the riser. Treads shorter than 11 inches must have a nose that protrudes at least 3/4 inch past the riser line, according to IRC 2018. Studies have shown that 3/4 inch overhangs are also among the safest overhang depths.

Maximum overhang for stair treads

The International Residential Code identifies the maximum projection of the nose at 1-1/4”. Steps that extend too far beyond the riser present a trip hazard when going up and a slip hazard when going down. The overhang increases the available footroom, but you must maintain a 10-inch clearance.

Stair nosing for carpet

Stair carpets muffle the sound of footsteps and are aesthetically pleasing to some. The thickness of the stake must not add more than 1-1/4 inch to the overhang of the ladder or be less than 3/4 inch when installed.

Lateral overhang of the stair step

The side stair overhang is generally aesthetic and covers exposed side seams. Staircases closed on one or both sides do not need any lateral overhangs. Side rails are not required, but when used they often match the overhang at the front edge of the step and should not extend more than 1-1/4 inches above the rail.

Tread overhang on deck stairs

Building regulations often treat indoor and outdoor stairs as a single entity. The tread is at least 10 inches, the maximum height is 7-3/4 inches, and the width is at least 36 inches above the height of the railing. Treads shorter than 11" must also have a 3/4" to 1-1/4" overhang that extends beyond the riser or riser line.

Deck stair treads are often made from two 2×6 or 5/4×6 decking boards for an actual combined depth of 11 inches. Sometimes 2×12 boards are used, but are 11-1/2 inches deep, so they must be ribbed or notched to meet regulations. The profile barrel unit with no overhang is a factor of the stringer design and the overall rise. The depth of the nose depends on the individual stroke of the stringer unit. A 10" run would result in a 1" overhang two 2x6 or 5/4x6.

External stairs do not require a closed riser. Heopen elevatorallows for better airflow and makes it easier to remove dirt and snow. However, it should be noted that the space between steps that are 30 inches above ground or level cannot accommodate a 4-inch diameter ball.

Diploma

The tread bar should stick out between 3/4" and 1-1/4" unless the tread is 11" or deeper. The stair nosing increases safety by expanding the horizontal space to ascend and descend and visually defines the nosing of the step. The overhang also hides the connection between the tread and the riser for a more aesthetically pleasing finish.

I hope you have a better understanding of stair parts and how far the riser step should protrude and why. If you found the article useful, please share it with others. As always, your comments and suggestions are welcome.