These stairs make a 180-degree turn, usually via a landing. They are practical in commercial spaces due to their compact nature.
U-shaped stairs, also known as half-turn stairs or switchback stairs, are commonly used in both residential and commercial settings. These stairs make a 180-degree turn, creating a shape that resembles the letter “U”.
What are the primary uses?
- Space Management: U-shaped stairs are often used in buildings where space is limited. They can be more compact than straight staircases, as they fold back on themselves.
- Architectural Appeal: The U-shaped design can add an appealing architectural feature to a building’s design, creating a focal point in the home or building.
- Break in Elevation: The landing in U-shaped stairs, usually located in the middle of the staircase, provides a resting spot, making these stairs comfortable for climbing, especially in tall buildings.
- Safety: The landing can also break a fall, making these stairs a safer option compared to long, straight runs of stairs.
- Privacy: U-shaped stairs provide a visual barrier between floors, which can be desirable in certain architectural layouts to increase privacy.
- Interior Design Flexibility: The landing area of U-shaped stairs provides space for interior decoration, where artwork, photographs, or plants can be displayed.
In industrial or commercial settings, U-shaped stairs might be used for similar reasons, such as space efficiency and enhanced safety. They can provide access between floors in multilevel warehouses, factories, or office buildings. In these settings, they must meet the safety standards and guidelines set by regulatory bodies like OSHA or follow local building codes.
U-shaped stairs, also known as half-turn or switchback stairs, that comply with both OSHA (Occupational Safety and Health Administration) and IBC (International Building Code) standards incorporate specific features aimed at ensuring user safety and accessibility. Key features of OSHA and IBC compliant U-shaped stairs include:
- Stair Width: According to the IBC, stair width should be at least 44 inches if a building can accommodate over 50 people, and 36 inches for buildings that accommodate fewer than 50 people. OSHA requires a minimum stair width of 22 inches.
- Treads and Risers: Per IBC standards, the maximum riser height should not exceed 7 inches, and the minimum tread depth should be 11 inches. In the case of industrial stairs, OSHA standards require risers to be from 6.5 to 10 inches and tread depth to be a minimum of 9.5 inches.
- Landings: Both OSHA and IBC require landings at appropriate intervals. The IBC requires landings at the top and bottom of the stairs and every 12 feet of vertical rise. The width and length of landings should be at least as wide as the stairs.
- Handrails: For stairs with four or more risers, handrails are required. The IBC specifies that handrail height should be between 34 and 38 inches, while OSHA requires them to be between 30 and 37 inches, unless the stairs are being used by children.
- Guardrails: Both OSHA and IBC require guardrails on open sides of stairways to prevent falls. IBC mandates that guardrails be at least 42 inches high, while OSHA requires them to be between 42 inches and 45 inches.
- Non-slip Surfaces: Stair treads should be slip-resistant as per OSHA guidelines.
Remember, these are general requirements, and the exact standards can vary depending on the specific use of the stairs, the nature of the work being performed, and local building codes. Always consult OSHA and IBC standards or a safety professional to ensure full compliance.
The Americans with Disabilities Act (ADA) and the International Building Code (IBC) provide certain guidelines and standards to ensure that U-shaped stairs (also known as half turn stairs or switchback stairs) are safe, functional, and accessible. Here are some of the main features for ADA and IBC-compliant U-shaped stairs:
- Width: According to the IBC, stairways should have a minimum width of 44 inches, although in certain residential circumstances, this can be reduced to 36 inches. While the ADA doesn’t specify stair width, it should be wide enough to allow for easy passage of individuals, including those using assistive devices.
- Rise and Run: The IBC states that the maximum riser height should be 7.75 inches and the minimum tread depth should be 10 inches. The ADA doesn’t specify these dimensions, but stairs should be accessible and safe for all individuals.
- Handrails: Both the ADA and the IBC require handrails on both sides of the stairs. According to these guidelines, handrails should be between 34 and 38 inches high, and should extend beyond the top and bottom of the stair flight, with the ends returned smoothly to the floor, wall, or post.
- Stair Landings: Both the ADA and IBC require landings at the top and bottom of the stairs, and where the stairs change direction. ADA stipulates that the landing should be at least as wide as the stairway and at least 60 inches long, measured in the direction of travel. The IBC requires the landing length to be a minimum of 36 inches, measured in the direction of travel.
- Stair Nosing: The IBC recommends that the stair nosing should not be more than 1.25 inches and not less than 0.75 inches. The ADA recommends that stair nosings be visually contrasted from the rest of the tread to avoid tripping hazards and should be beveled or rounded.
- Guards and Balusters: The IBC requires that guards be at least 42 inches high and that openings in balusters should not allow the passage of a 4-inch diameter sphere.
- Accessible Routes: The ADA requires that an accessible route be provided where stairs are present. This might require the installation of ramps, lifts, or elevators alongside stairs.
These are general guidelines, and the specific rules and regulations can vary depending on local building codes and the specific requirements of the ADA and IBC. Always consult with a professional or local building authority when designing or evaluating U-shaped stairs for compliance.