Interiors
How many spindles do I need for my staircase?
Expert Lucie Levesley, director at Jackson Woodturners reveals how to calculate the correct number of spindles needed for your staircase design.
Designing your own staircase can be daunting, especially when it comes to ordering the correct number of parts. Ordering too many can put an unnecessary hole in your pocket, whilst ordering too few can lead to annoying and often costly delays. That’s why stair parts expert, Lucie Levesley, director at Jackson Woodturners has shared her tips on calculating the correct number of spindles needed for your staircase project.
Lucie Levesley director at Jackson Woodturners said,
“Spindles (also known as balusters) are the vertical posts that connect the base rail and handrail on your staircase. They form part of the balustrade; which is the collective name for the base rail, handrail, newel post and spindles.
“Spindles come in a variety of materials, with the most popular being made out of wood such as oak and pine. Black metal spindles are also increasing in popularity in recent years.”
Lucie Levesley, Director
Lucie continues,
“A common mistake is buying too many or too few spindles, which can waste both time and money for home renovators. Whether that’s being left short midway through installation and having to wait for more to be delivered or because you ordered too many, spending money on items that you have no use for. Our spindle spacing calculator, helps renovators avoid both of these scenarios, enabling buyers to confidently order the correct number of spindles the first time around.”
How to calculate staircase spindles and spacing
Step 1: Pick your spindles
Spindles come in a variety of types and widths, with the most popular being wooden and metal spindles. Wooden spindles are usually 32mm or 41mm (in width).
It is important to note the sizing of your selected spindles, alongside whether they are straight or turned, as the spacing calculation you need to use will change based on these factors.
Step 2: Take your staircase measurements
Take separate measurements for each section of your current staircase, i.e. the main stair run, the landing and any additional sections. This will make it much easier to work out the exact amounts of materials that you need, and minimise waste.
Staircases generally come in two different types, closed-string and cut-string (also known as open tread). The number of spindles you need to order will differ depending on the stair type.
Closed-string stairs require a specific calculation whereas a cut-string, open-tread staircase simply requires two spindles per step.
Spindles used on a landing balustrade are calculated using the same formula as a closed-string staircase.
A = Length of staircase
B = Going of flight
C = Going of landing
Closed string staircases
For a closed-string staircase, you will need to measure:
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Measure the “length of the staircase” (mm)
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The angle or “pitch” of the stairs (degrees)
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Convert this to the “going of the flight” (mm)
Lucie comments,
“To find the going of the flight measurement, we recommend working from the length of the staircase and its pitch, using a tool such as Cleave Books. This will give you a more accurate figure, as measuring the going of the flightdirectly with a tape measure can be tricky.”
You will also need to,
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Measure the going of the landing (mm)
Cut string, open tread staircases
However, for a cut string, open tread staircase you will instead:
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Count the number of steps (stair treads)
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Measure the going of the landing
Lucie notes that,
“Staircase type also affects the spindle lengths required. For example, cut string staircases have a uniform length throughout, whereas an open tread staircase usually requires two different lengths of spindle for each step. The two different length of spindles needed for cut string, open tread stairs is because of the increased height of the handrail towards the back to the step. This accounts for the incline of the stairs.
Step 3: Calculate how many spindles are needed
Based on the spindle type chosen and the measurements taken, renovators can then use the below calculations.
Closed string staircases and landing balustrades calculation
For a closed-string staircase, you will need to work to calculate the number of spindles needed for the flight of stairs and calculate the number of spindles needed for the landing balustrade.
These two figures should then be added together.
For example, if you are using plain wooden spindles which are 1100mm tall and 32mm wide, on a staircase with a going of flight of 2,600mm and a going of landing of 1,000mm, then your calculation would be…
2,600 mm / 125 = 21 spindles
+
1,000mm / 125 = 8 spindles
Total number of spindles required = 29
Lucie’s top tip,
“Always work out the number needed for the stairs and the number of spindles needed for the landing separately, before adding the two figures together. I’ve seen people get caught out before by rounding errors, leaving them a spindle short.”
Cut string, open tread staircases calculation
However, If you have a cut string, open tread staircase, then the figures used for the calculation will be different to those mentioned above. You must have two spindles per stair tread - half of these should be 900mm in length and half should be longer, at 1100mm.
For example,
12 stair treads = 24 spindles in total = 12x 900mm & 12x 1100mm
If you have a landing which requires spindles too, this calculation should be made as shown in the landing balustrade section above.
Using our example of plain wooden spindles which are 32mm wide,
1,000 mm / 125 = 8 spindles
Total number of spindles required = 12x 900mm & 20x 1100mm
Alternatively, you can visit the Jackson Woodturners Spindle Calculator and input your staircase requirements. The calculator will do the hard work for you, generating exactly how many spindles you will need to order for your project.
