You see them every time you go up or down a set of stairs, but probably never think about them and unless you are in the construction business may not even know what they are called. A stair stringer is the most important component of a set of stairs, with these you could not have stairs as there would be nowhere for the treads to sit on. The stringers are the zigzag frames that are usually found on the sides of the stairs, although in more modern building often close to the middle that the treads you place your feet on rest on.
It is the stair stringer that provides the framework for the stairs, depending on how they are cut the stringers set the height and width of each step. In medieval times the stringers were mostly created out of stone or brick and had wooden treads lay on them or the steps might also have been made from stone or mud. If you look at the stairs in your home you are most likely to find that the stringers are made from single lengths of board that have had L shaped notches cut out of them for the treads to sit on.
This has long been the easiest form of stair stringer as one can cut them with a circular saw and most homes use two identical stringers for each set of stairs. Tread are usually glued and then screwed in place to keep them secure and to stop them squeaking as people use the stairs. To help further reduce the possibility of squeaking better builders add in a third stringer that runs down the middle of the stairway reducing the amount of movement for each tread.
Spiral staircases have long been very popular in commercial applications, while stairs are a very practical way to move from one floor to another, this type of stairs are also considered very aesthetically pleasing and take up far less space.
How the stair stringer used to create this type of stairs is invariably made from metal. The reason for this is that the modern spiral staircase is in fact not so much a spiral as it is a helix and the metal stringers have to be carefully bent to very exacting specifications if the stairs are to be level and comfortable to use.
In the true mathematical sense these stairs are not a true spiral since a spiral is a one dimensional figure. Each stair stringer is actually a helix, which in mathematical terms is a three dimensional figure. A spiral staircase is a double helix to the extent that each stringer is a different helix to provide for a flat comfortable tread pattern making it possible to walk up and down without falling. It takes a dedicated team of specialists like those at Albina Pipe Bending to bend a piece of flat steel into the helixes you will need to build your spiral staircase. Let this team of professionals bend your next set of stringers for you.