Spiral staircases are not only a means of saving space for getting from floor to floor. They are also a design element in your home. Typical spiral staircases can cost as much at $20,000 because of the time consuming work that is involved. Build on yourself for a fraction of the cost and create a space saving, cool stair case.
Figuring Out the Stairs
When building most staircases, you have to figure out the rise and the run of the stair treads (how much each step goes up and how wide each set needs to be). When figuring out spiral staircases, all you need to figure out is how many steps you need and the rise (height of each step. Building code requirements state that you need a minimum of a 3 foot wide stair case and the treads should be between 4 and 8 inches tall and 9 to 12 inches wide. So lets use an example. I would like to build a spiral staircase where all the steps are 7 inches tall. Lets say it is 9 feet 4 inches from the top of the bottom of the top floor to the bottom floor where your staircase starts. So you have 112 inch ((9×12)+4 = 112). 112/7 = 16 steps. Now one of these steps is the actual floor so you will need to subtract 1 step so you have 15 steps you will need to build.
You will need to buy 4 inch collars if you are mounting to a metal pipe, or 6 inch collars if you are mounting to a wood pole. Make sure that the diameter of the collar allows the pole to slide through the collar.
Cut a 14 inch piece of 1 inch angle iron and two pieces of the same angle iron that are 3 feet 6 inches long. Clamp the pieces together so that the ends of the long pieces are positioned on the metal collar. Then clamp the 14 inch piece to the opposite ends of the angle iron. The angles should all be clamped together so that the angle iron faces down. In other words, the top should be flat. This is the frame of your steps. Weld the pieces together with a wire welder and grind the corners to often them slightly. Repeat this process 14 more times to make all of the frames for your steps. Make sure that all of the step frames are the same.
Cut out heavy gage perforated metal with an angle grinder the shape of the steps. Weld the mesh into place on the angle iron. The mesh should not bend when stood on. Repeat for the rest of your steps. Grind of any sharp edges and paint wit ha metallic coating that is corrosion proof.
Installing The Spiral Staircase
Measure the distance from the ceiling of the second floor to the bottom floor. This is the distance the pole needs to be. Place a 16 x16 inch 1/8 inch steel plate on the bottom floor with holes in each corner for bolting the plate to the floor, and position the pole in the center of the plate. Weld the pole in the center of the plate and grind away the edges. Slide each step you made down the pole so they are stacked on top of each other on the pole.
Slide a 16×16 inch 1/8 inch steel plate with holes in the corners for mounting between to the ceiling joists and weld it in the center of the pole.
Slide the first step down from the second floor up. So that it is positioned perfectly 7 inches to step down from. Tack weld it into place between the collar and the pole, or bolt it to the pole if it is wood. Then make sure that you have the pole perfectly positioned and level. Once you are satisfied with the orientation of the pole, bolt it to the floor and ceiling, making sure that you hit the floor and ceiling joists. You may need to add framing in these areas to catch the self tapping bolts.
Now Measure all the way down the pole from the bottom of the sleeve and mark every 7 inch increment until you get to the floor. If you made you sleeves correctly, you should be able position the sleeves on the marks, get the tread positioned and weld the steps into place. You should double check each step either way.
You will need to have a guardrail installed. Because this is a complicated process, I will outline this in a separate article. Paint the treads if necessary and clean up any welds with the grinder.
Spiral staircases are an artful addition to just about any space that saves space while bringing it to life.