Stairs, Handrails & Guardrails
The following are requirements for stairs, handrails, and guardrails in the City of Hopkins. Because circular and spiral stairs are rarely used in residential construction, those types of stairs are not covered. If you are contemplating the use of one of those stair designs, please contact the Inspections Department.
The following spatial requirements apply to stairs:
- Minimum width above the handrail height is 36 inches.
- Handrails may project not more than 4 ½ inches from the side of the stair.
- The minimum clear width from the handrail height to the treads is 31 ½ inches for stairs with rails on one side and 27 inches for stairs with rails on both sides.
How to measure stair headroom
Riser height and tread depth
- A minimum of 6 feet, 8 inches of headroom is required measured vertically from the nosing of the treads. 6 feet, 8 inches of headroom is required at all landings.
- The maximum riser height in any stair may not exceed 7 3/4 inches measured from the top of one tread to the top of any adjacent tread.
- The minimum tread depth shall be 10 inches measured from the nosing of one tread to the nosing of any adjacent tread.
- The greatest tread or riser dimension shall not exceed the smallest tread or riser dimension by more than 3/8 inch.
- Open risers are not permitted when the total rise of the stair exceeds 30 inches unless the open space is such that a 4-inch diameter sphere will not pass through.
- For winder stairs, the width of the tread must be at least 9 inches at a point 12 inches from the side where the treads are narrowest. The minimum width of any tread may not be less than 6 inches. A continuous handrail is required on the side of the stair where the treads are narrowest.
- When the underside of stairs is enclosed with walls and a door, the walls, ceilings, and under side of the stair must be covered with ½ inch gypsum board.
Stairs must be designed for a 40 pound per square foot uniformly distributed live load. Treads must be designed for the uniformly distributed live load or a 300-pound concentrated load acting over an area of 4 square inches, whichever produces the greatest stresses.
Handrails are required on at least one side of all stairs with four or more risers.
- Handrails must be mounted between 34 and 38 inches above the nosing of the stair treads.
- Handrails must extend from a point directly above the bottom riser to a point directly above the top riser.
- Handrails must be continuous for the entire length of a flight of stairs.
- The ends of handrails must be returned to the wall or terminate in a newel post.
- Handrails adjacent to a wall must have a space of not less than 1 ½ inches between the handrail and the wall.
- Handrails must be designed to support a 200 lb load applied in any direction at any point along the top of the rail.
- Handrails must meet the following grip size requirements:
- The handrail must have a circular cross section of 1¼ inches to 25/8 inches.
- Other handrail shapes that provide an equivalent grasping surface are permissible.
- Edges of handrails shall have a minimum radius of 1/8 inch.
- The use of a 2X4 or other dimension lumber placed either on edge or flat is not an acceptable handrail.
Acceptable handrail details (Note: Other shapes may be acceptable if they provide an equivalent gripping surface)
Guards are required for any porch, balcony, deck, or other raised floor surface that is located more than 30 inches above the floor or grade below. Guards at these locations must be not less than 36 inches in height.
Guards are required on the open side(s) of stairs with a total rise of more than 30 inches above the floor or grade below. Guards on stairs must be not less than 34 inches high measured from the nosing of the treads.
All guards must:
- have intermediate rails or a decorative pattern such that a 4-inch diameter sphere will not pass though. The triangular space formed by the bottom or a guard, a stair riser, and stair tread may be such that a 6-inch diameter sphere will not pass through.
- be designed to support a 200 lb load applied in any direction at any point along the top of the guard.