Spiral stair design, Part 3

Complete a spiral staircase design to a loft floor

Now let’s find the best spiral staircase design for the floor plan labeled Example 1 in Figure 1 (see Spiral stair design, Part 1).  This spiral has 10 treads and will turn 300 degrees.  The landing will attach to the loft floor on one side.

Figure 9 shows the only two layouts (from Figure 8) that might work.  The NW layout of the LH spiral, and the NE layout of the RH spiral.  These have landing edges that must attach to the top floor in the correct positions (refer to Figure 3).  We have sketched the directions to the bottom treads for 300-degree spirals.   

This is a spiral staircase design to reach an open loft floor
The NW Left Hand layout will not work well.  Because to miss the fireplace you would have to duck under the upper spiral to get to the bottom tread.

The NE Right hand layout will work best.  You travel in the desired direction of access and take a slight right turn to get to the bottom tread.

Spiral stair design for an open stairwell

Figure 10 represents the spiral staircase design using the floor plan shown in Example 2.  This spiral will have 12 treads and turn 360 degrees.

We have selected from Figure 8 the layouts NW and SW for both Right Hand and Left Hand layouts.  The other landing positions do not fit against the stairwell’s left edge.  Both Right Hand layouts will not work.  Because these put the lower access opposite the desired access.

The SW Left Hand layout could work by following the desired path and turning left to reach the bottom tread.  But the rotation of the NW layout 20 degrees counter clockwise provides both desired accesses perfectly.  We labeled this layout NW-2.

Spiral staircase design for an enclosed stairwell

Next we work with the layout of Example 3 (see Figure 11).  This is an 11-tread spiral that turns 330 degrees.

Only the SW and SE layouts of Figure 7 will place the landing in line with the desired top access.  (Because in Figure 7, the NE and NW landings are positioned against the back wall.)

Both Left Hand layouts do not have lower access as desired.  But both Right Hand layouts will work after some rotation.  We rotated the SE layout 50 degrees clockwise to get SE-2, and we rotated SW 35 degrees counter clockwise for SW-2.  We chose SE-2, because it provided a lower access in the exact direction as desired.

Before leaving you, we offer a hint that may help when you consider a new spiral staircase design.  You do not need to imagine the best layout in Figure 8.  Instead, sketch the layouts on small note pages and mark the lower accesses on these.  Now you can place them directly on your floor plan and move or rotate them to see the best fit.

The three examples we presented are fairly common spiral stair layouts.  Hopefully these articles will get you off to a good start.  But if you have any questions contact your spiral stair manufacturer for the solution they would propose.  At least you will already understand much of their work.

Click here for Spiral stair design, Part 1

Click here for Spiral stair design, Part 2