Build a Spiral Staircase in Your Home: Measuring and Installation Build a Spiral Staircase in Your Home: Measuring and Installation

Once you've decided on a design and understand the minimum code requirements, you still have some calculations to do.

  • Decide on the exact location of your staircase. By code the minimum width of the staircase is 5' so you need an  unobstructed space 5' square on both the lower level and upper levels. Plus, at the top of the stairs you need to have 6'6” of unobstructed space for people to stand up.
  • After deciding on the location, you need to carefully measure the overall height from lower level to upper level (floor to floor). This measurement needs to be exact since it will ensure the top landing is exactly the same level as the upper floor. Note: measuring from 'floor to floor' is not the same a measuring from 'floor to ceiling' - if you only measure from 'floor to ceiling' your measurements will be too short and your spiral staircase won't fit your space.
  • Next determine the number of steps you staircase needs by dividing the floor to floor height by 8 (9” is the maximum, but 8” risers are much easier to walk on . For example is the floor to floor height is 8 ½' (102”) divide 102 by 8 to give you 12.75. Since you can't have fractional steps, choose 13 steps (including the top deck) and your risers will be 102 divided by 13 or 8.3 inches.

Finally after doing all your measurements and calculations it's time to install your spiral staircase.

  • Draw lines from corner to corner of your staircase location to determine the exact center and mark it – this is  where you will install your center post. Secure the base plate to the floor with the included hardware, screw the center pole onto the plate and follow up by sliding the base plate cover onto the pole.
  • Now you will need to hold the center pole upright while installing the stair treads. Having a helper at the top is great, or you can hold the pole in position by tying it off to something solid upstairs.
  • Install the stair treads onto the pole starting from the top. Alternate the treads from left to right during installation to help keep the pole upright.
  • After installing the treads screw the newel post support (to hold the handrail) in position, then after ensuring the landing is level, install it.
  • Finish your spiral staircase installation by adjusting the treads to the proper positioning ( 8.3” apart in our example), install and securely fasten the handrail, set the newel post in its final position and double check everything has been tightened.

Now that your new staircase is installed, let's stay safe and remember - “No running on the stairs."

Part One | Part Two

Murray Anderson is an experienced freelance writer over 800 articles published on the web as well as in print magazines and newspapers in both the United States and Canada. He writes on a wide range of topics and is a regular contributor to He can be contacted at [email protected]

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