There is much confusion over the proper length and depth of the stair tread and riser overhangs.
While the International Residential Code provides guidelines on the minimum height and width of these features, a little overhang on a one-inch thick step will provide enough space for the heel to tuck under the overhang on the descent.
Whether an overhang is necessary depends on the construction details of your stairs and can vary from one style to another.
What is the size of an overhang?
Generally, overhangs should be 3/4 to 1 inch. This can be dangerous if the overhang is too high, but too small can create more risk. Overhangs on stair treads are not required if the treads are 11 inches or less.
However, the International Residential Code does specify a minimum stair rise of 7-3/4 ” and a maximum stair rise of 7-3/4″. In most areas, no overhangs are required, but the height is a factor for determining the number of treads.
Stair Riser height (an overview)
Treads are also required to have a minimal overhang and a maximum of 1-1/4″. The height of the stair riser must be at least 10″ above the railing height to be compliant with the building code.
The treads should be at least 11 inches in width and must not extend beyond the top surface of the stringer.
A side overhang must be at least 3/4″ deep, and the depth of the tread should be uniform throughout the flight of steps. The treads’ noses must have a minimum overhang of 0.375″ and a radius of less than 0.5-inch.
The riser of stairs must be between three-eighths of an inch and one-half inches. The riser can be up to 30mm in diameter.
In outdoor settings, no riser is required. This overhang will improve safety and prevent slips.
It is recommended to install an overhang on the stair tread if you want to reduce the risk of falling. It will also improve the airflow on the stairs.
Overhang for indoor/outdoor stairs
The minimum overhang for indoor stairs is between 3/4 and 1-1/4″ while the overhang of an outdoor stair is between one-half and one-inch. In addition, the riser’s overhang must be at least eighteen inches. An open riser will improve safety and airflow.
The minimum run and rise of a stair is 10 inches. If you have an outdoor staircase, it must overhang between seven and eleven inches.
Why use stair nosing in the first place?
The use of a stair nosing is a good idea for many reasons. It improves visibility and can help those with poor eyesight. It can also be helpful for older people or those with poor vision.
Overhanging on a staircase can help prevent tripping, as it protects the stair treads from slipping. Furthermore, it can help people who have trouble seeing can benefit from an overhang.
Overhanging is not required for a single stair. Depending on the height of the stairs, overhangs can be left open or enclosed.
Overhanging the riser is essential for safety, as it is not only a tripping hazard but also for aesthetics. For safety reasons, it is important to choose a stair nosing with a minimal overhang.
Then, you can consider the use of carpet on the landing.
Conclusion
In general, a stair tread needs an overhang of at least 3/4 inches on the face of the riser. If it is 11 inches or deeper, there is no need for overhanging.
The edge of the stair tread should be rounded or beveled. The edge of a stair tread needs an overhang when it is curved. It’s not always necessary for an overhang, but it is recommended.
The riser and the treads are not parallel to each other. The risers must extend at least half the length of the stairs. The difference between the two surfaces is the distance between the riser and the tread.
Overhanging is necessary for safety purposes. The height of the riser should not exceed the height of the stairs.
The overhang should be no greater than 7 3/4 inches. The height of the riser and the tread must be the same.
