Stair Riser Tread Ratio

A riser higher than 7 inches is not recommended outside though interior stair dimensions can be higher than that.

Stair riser tread ratio.

7 riser height tread depth y 0 7535 37 slope. Handrail graspability to be either type i or ii with a minimum 1 1 2 inch clearance from a wall. Treads the tread depth b should not be less than 10 inches 254 mm. The ratio for exterior stairs is two risers the tread 26 inches.

At stair riser specifications and at stair dimensions width height you ll read that stair risers should be 7 inches 178 mm maximum and 4 inches 102 mm minimum. Maximum 7 3 4 inch stair riser height. You ll find the tread width in the column on the left and the rise height in the column on the right. Building stairs for your deck is often considered the most difficult part of the construction project.

Or use the handy chart below with the ratios already figured for you. The r r then was 16 too low and 2r r was 28 too high. Fortunately the stair is used primarily for storage. Typically a single 2x12 or two 2x6s are used for stair tread material.

Stairs with solid risers and 2x12 treads. Step tread 2 riser 26 or 27. Building codes generally suggest that the minimum length of a tread be 10 inches 25 4 cm. It is not the physical height of the riser because this excludes the thickness of the tread.

Handrail height to be placed a minimum 34 inches to 38 inches. Rise r 12 run r 4 r r 16 too low 2r r 28 too high won t be comfortable. We would need change the stair tread depth to make a 37 slope stair that has an acceptable 7 inch riser height. The rise or height of a step is measured from the top of one tread to the top of the next tread.

Aside from the treads being too small for safety the rise would have been about 12 and the run about 4. The optimum riser for exterior stairs is 6 1 2 inches making the tread 13 inches wide. Minimum 10 inch stair tread depth with nosing or minimum 11 inches with no nosing. Having the right calculations before getting started can make the task a lot easier.