The terminology and regulations of spiral staircases can be difficult to remember. We break it down for you in an easy guide. Mylen’s Code Stair Packages are compliant with the following requirements. We recommend that you speak in detail with our Stair Designers to learn more about meeting code for your spiral staircase project.
Clear Walking Path
You will need a minimum of a 26” clear walking path. In order to achieve this, you will need a spiral stair that is at least 5’ in diameter.
All of your treads need to be identical to meet code. Treads need to have a 7 ½” depth at 12” from the narrow edge. The spiral staircase’s tread rises must not exceed 9 ½”. The rises are essentially the open space between the treads.
Spirals need a minimum headroom of 6’ 6”. In order to measure headroom, start at the edge of the top platform and measure down to the bottom tread. That distance has to be at least 6’ 6”.
Width of the Landing
The width of the stair’s landing should not be less than its clear walking path.
The space between the balusters should be spaced in such a way that a 4” object cannot pass through them.
The space between the balusters on the balcony guardrail must also be spaced so a 4” object cannot pass through them. The height of your balcony guardrail must also be at least 36”.
The spiral needs a handrail on the wide edge of the treads and it must be at least 34” and no more than 38” in height. Ask our designers about spiral stair handrail grip size to meet code.
300 lb concentrated load is required
Souce: Salter Spiral Stair