Spiral stair landing designs are a vital part of any spiral staircase installation. Building codes require at least 78″ above all parts of a spiral stair. Landings, usually installed level with the top floor, provide this headroom as you go down the stairs. (See Spiral stair planning: why spiral stairs need a top landing).
Spirals with treads that turn 30 degrees each* often need a landing with an angled edge to allow 78″ under the landing.
* Treads that turn 30 degrees meet building code width requirements.
Three possible configurations cover most spiral stair landing designs. These configurations are:
One, angle the leading edge. This pulls a lower tread out from under the landing (Figure 1a).
Two, you could angle the adjacent edge to expose a lower tread (Figure 1b).
Three-sided spiral stair landing designsThree, you could design the landing to have only three sides (Figure 1c). This provides more headroom using either of the two methods mentioned above. The triangular design can improve access on the top or bottom floors.
Landings require handrails to protect open edges. Figure 2 shows where you might require these handrails for each landing configuration.
Only certain spiral stairs provide headroom with a square (90-degree) landing. These stairs are usually 6”-0″ diameter and larger. Their treads turn much less than 30 degrees (see Figure 3). You step down enough times for safe headroom under the landing. Sometimes these spirals can be designed with low rises that are easier to climb and still provide enough headroom.
Some manufacturers make narrow-angle treads with a pad that covers the narrowest end. The uncovered portion of the tread has enough width to meet code requirements.
Figure 4 shows extended spiral stair landing designs. These can reach the top floor when the spiral is located further away than usual.
Spiral stair landing designs can improve headroomYou can install the landing below the top floor. This provides headroom under a sloped upstairs ceiling (see Figure 5). The local building inspector may limit the maximum distance down from the floor.
Installing the landing below the floor reduces the spiral height and may provide better access on the first floor. Figure 6 shows the shorter spiral with one less tread, relocating the bottom tread on the first floor.
Spiral stair landing designs can be decorative with curved sides and matching curved handrails (Figure 7). These are supplied with spiral stairs with curved treads and fit nicely coming up through a circular stairwell on the second floor.