Measuring and installing a spiral staircase

The first thing that you will need to do after you have decided on the design is some calculations:

Find the right location for the staircase. The minimum width of the staircase is 5′, so have this in mind. At the top of the staircase you will need to have 6’6” space to allow people to stand up.
Next you will need to measure the height of the staircase, from the lower to the upper floor. But be careful to measure from floor to floor, and not from floor to ceiling. Consider the width of the ceiling.
Now you can calculate the number of steps. 8” high risers are much easier to walk than 9” risers, so divide the height by 8 and you will have the number of steps.

Now it’s time to install the staircase:

Determine the exact center of the staircase and mark it by drawing lines from one corner to another. This is where the center post will go. First of all secure the base plate to the floor using the hardware provided.
Now hold the center pole straight up while you install the stair treads. You can get someone to help you or you can tie it to something solid.
Start from the top and install the stair treads. Help keep the pole upright by alternating the treads from left to right.
Now screw the newel post support in position. This will hold the handrail.
Adjust the treads to the proper positioning. Fasten the handrails, set the newel post in its position and see if everything is nice and tight.