Spacing spindles on a staircase involves determining the correct number of spindles and their placement along the treads and rake (the angled part of the handrail).
A common method for determining the number of spindles needed, which guides spacing, is based on the number of steps on the staircase flight.
Calculating the Number of Spindles Per Flight
According to common practice, and as noted in the reference, you can calculate the approximate number of spindles required for a single flight of stairs (excluding landings) using a simple formula:
- Count the total number of steps (or treads) on the flight.
- Multiply this number by two (to account for two spindles per step, which is a typical arrangement).
- Subtract two from the total (as you usually need only one spindle at the bottom and one at the top step near the newel posts or walls).
The formula from the reference is:
(Number of steps * 2) - 2
This calculation provides a starting point for the quantity of spindles needed for a flight, based on the arrangement of approximately two spindles per step.
Example Calculation:
Let's say your staircase flight has 12 steps.
- Steps = 12
- Multiply by 2: 12 * 2 = 24
- Subtract 2: 24 - 2 = 22
You would typically need around 22 spindles for this flight using this method.
Placement and Actual Spacing
While the "two spindles per step" method helps calculate the number of spindles, the actual spacing between them is critical and must comply with building codes.
The most important rule for spindle spacing is the 4-inch rule. This means that the gap between any two spindles, and between a spindle and any other part of the stair railing system (like the newel post or wall), must be small enough that a 4-inch sphere cannot pass through it. This is a safety requirement, primarily to prevent small children from falling through or getting stuck.
Practical Steps for Spacing:
- Determine the Number: Use the method described above (or another calculation based on the total length of the rake) to find the approximate number of spindles needed.
- Calculate the Available Space: Measure the total horizontal distance along the rake where the spindles will be installed.
- Account for Spindle Width: You need to consider the width of each spindle and the gaps between them.
- Trial Layout: It's often best to perform a trial layout on a long piece of wood or the staircase itself. Mark the positions of newel posts or walls. Then, starting from one end, mark the positions for the calculated number of spindles, ensuring the gaps between them are consistent and do not exceed 4 inches.
- Adjust as Needed: You may need to add or subtract a spindle or slightly adjust the spacing to ensure all gaps meet the 4-inch code requirement and the spindles are evenly distributed for aesthetic appeal. Spacing is usually measured from the edge of one spindle to the edge of the next.
Key Considerations:
- Building Codes: Always check your local building codes, as the 4-inch rule is standard but specific regulations can vary.
- Aesthetics: Even spacing is crucial for a visually appealing staircase.
- Handrail and Baserail: Spindles are installed between the handrail and either the treads or a baserail on top of the treads. Proper measurements must be taken between these points.
By combining the spindle count calculation method (like two per step adjusted for ends) with careful measurement and adherence to the 4-inch spacing rule, you can effectively space spindles on your staircase.
