3 ms·

Can you explain the difference between a "regular spiral staircase" and a "geometric staircase"?

jimnotgym 9y ago
In a spiral staircase the stairs 'rotate' around a small diameter centre pole. They save a lot of space but seriously limit access for large items. They can be useful to access a loft space for example, where you want something better than a ladder but don't want to lose much floor space below. The small diameter centre pole seriously limits the way timber can be jointed. Long lasting timber joints need ways to deal with shrinkage, and therefore are better with a large contact area. Spirals are better made out of metal for this reason. Most of the images here are a much grander form of stair that 'rotate' around a large stair well leaving a large open space in the middle, which makes it easy to move furniture up by overhanging the handrail or even winching up the middle. The well can be circular or elliptical at the turns, and often have straight flights between. Since building a set of geometric stairs is complex and time consuming it is unlikely that you will see them outside of grand hotels and stately homes. It is likely that the simplest ones built in a traditional way would cost well over $100k. I struggled to find a reference that explained the true complexity outside of this classic book https://books.google.co.uk/books/about/Modern_Practical_Joinery.html?id=KzNSAAAAMAAJ https://books.google.co.uk/books/about/Modern_Practical_Join... Although here is a basic diagram here showing the curved strings and open well. http://year3shopfitting.wikispaces.com/Geometric+stairs http://year3shopfitting.wikispaces.com/Geometric+stairs Of course it is true to say that either type could have been made poorly and require maintenance, it is less likely that a common wood-butcher would attempt the second kind. Disclosure: I can use the term wood-butcher as in a former life I was qualified in that area!

In a spiral staircase the stairs 'rotate' around a small diameter centre pole. They save a lot of space but seriously limit access for large items. They can be useful to access a loft space for example, where you want something better than a ladder but don't want to lose much floor space below. The small diameter centre pole seriously limits the way timber can be jointed. Long lasting timber joints need ways to deal with shrinkage, and therefore are better with a large contact area. Spirals are better made out of metal for this reason. Most of the images here are a much grander form of stair that 'rotate' around a large stair well leaving a large open space in the middle, which makes it easy to move furniture up by overhanging the handrail or even winching up the middle. The well can be circular or elliptical at the turns, and often have straight flights between. Since building a set of geometric stairs is complex and time consuming it is unlikely that you will see them outside of grand hotels and stately homes. It is likely that the simplest ones built in a traditional way would cost well over $100k. I struggled to find a reference that explained the true complexity outside of this classic book https://books.google.co.uk/books/about/Modern_Practical_Joinery.html?id=KzNSAAAAMAAJ https://books.google.co.uk/books/about/Modern_Practical_Join... Although here is a basic diagram here showing the curved strings and open well. http://year3shopfitting.wikispaces.com/Geometric+stairs http://year3shopfitting.wikispaces.com/Geometric+stairs Of course it is true to say that either type could have been made poorly and require maintenance, it is less likely that a common wood-butcher would attempt the second kind. Disclosure: I can use the term wood-butcher as in a former life I was qualified in that area!