Spiral staircase
A spiral staircase, also known as a helical or circular staircase, is a type of staircase that curves around a central axis. While the term "spiral" is often used interchangeably with "curved staircase," there's a subtle distinction. A spiral staircase typically involves a rotation of more than 360 degrees, but in general, any staircase that follows a rotating path—whether it’s 30 degrees or a full 360-degree turn—is considered a spiral staircase. Some staircases have curved designs, but they may not follow a true spiral. For example, hyperbolic or parabolic curves don’t rotate around a fixed axis and are usually part of a larger design. These non-rotating curves often complement a spiral structure, forming what is called a compound curved staircase. As a result, many people refer to all curved staircases as spiral staircases, regardless of their exact geometry. The most elegant spiral staircases found in halls often span between 100 to 120 degrees. They gradually narrow from the base to the top, following a ratio of 4:3 at the wider parts and 3:2 at the narrower sections. In residential settings, marble spiral staircases typically have a step height between 150 and 170 mm. The narrowest part of the step should be at least 270 mm wide, while the widest part can go up to 480 mm. The total width of the staircase is usually between 900 mm and 1300 mm. In luxury settings, such as grand halls or high-end homes, the step height should be less than 150 mm for comfort. The narrowest point of the step must be at least 310 mm wide, and the overall width of the staircase should be at least 1300 mm, ideally over 2000 mm for a more spacious feel. The structural frame of a spiral staircase must be made of either concrete or steel to ensure stability and durability. The stone cladding on the staircase should follow a natural curve without abrupt changes. A well-crafted spiral staircase should give the impression of being carved from a single piece of stone, avoiding any disjointed or artificial look. It should feel seamless and elegant, enhancing the overall aesthetic of the space. Expansion Bolt,Stainless Steel Expansion Screw,Concrete expansion Screw Hebei Quanfang Fastener Co., Ltd , https://www.quanfangfastener.com