Stair Generator
Lorri Dent
The Stair Calculator is an online tool for calculating various parameters involved in the construction of stairs. Refer to the figure adjacent to the calculator as a reference. A fraction to decimal conversion table for common fractions used in measurements is also provided at the bottom of the page.
Stairs come in many different forms, and while building a basic staircase may appear to be a simple task, there are actually a number of parameters, calculations, and building codes that must be considered. These range from the length, width, and height of specific parts of the stairs, to where doors are placed in relation to stairs; the arc of a door must be completely on the landing or floor and not be allowed to swing over steps. Below is a list of some of the most common terminology regarding stairs, as well as some commonly used building codes. Building codes or requirements can differ at a local level, and a person building a staircase should refer to the codes specific to their locations.
Run/Tread: The run or tread is the part of the stairway that a person steps on. Its length is measured from the outer edge of the step, which includes the nosing if it is present, to the vertical portion of the stair called the riser. Both nosing and riser are discussed below. When measuring the total run of a staircase, the length of the tread above the last riser is not included in the measurement. Also, when nosing is present, the total run is not simply the sum of tread length, since the overhang caused by the nosing must be subtracted from the total run.
Rise/Riser: The rise, or height of a step is measured from the top of one tread to the top of the next tread. It is not the physical height of the riser because this excludes the thickness of the tread. The number of risers, not the number of treads, is used to determine the number of steps that comprise a staircase.
Nosing: The nosing is the protrusion at the edge of a tread that hangs over the riser below. Not all steps have a nosing, but when present, the nosing is included in the length of the tread. The main purpose of nosing is to improve safety by providing extra space on which a person can place their feet.
Headroom: Headroom is the height measured from the top of a tread to the ceiling above it. While building codes for headroom are primarily intended to ensure enough room for people to comfortably use the stairs, the codes typically require far more room than the average height of a person to allow for moving larger objects such as furniture.
Stair Width: Stair width is measured from edge to edge of each side of the tread, perpendicular to tread length. While measurements of length are conventionally longer than those of width when considering rectangles, in the case of steps, the width is usually the longer side. Stair width does not include handrails.
Handrails & Guards/Guardrails: A handrail is a railing that runs up a stair incline for users to hold when ascending or descending a staircase. A guard is "a building component or a system of building components located near the open sides of elevated walking surfaces that minimizes the possibility of a fall from the walking surface to the lower level." Guards can include rails (guardrails), but can be any number of other constructions such as walls, half-walls, or even a bench.
Stringer: A stair stringer is a structural member that supports the treads and risers of a staircase. Typically, there are three in a staircase: one on each side, and one in the middle. Stringers are not always visible, but can be seen on stairs with open sides. The stringers can either be cut to the shape of each step, or in some cases, are uncut and conceal the edges of the treads.
Does anyone know if it is possible to change the default run (tread depth) to something other than 11? If I change it in the settings dbx, it goes back to 11 once I close the dialog box. Same thing for the default rise.
If you lock the tread depth, the program should maintain whatever tread depth you specified. If you set this in your stair defaults, any new stairs you draw should also be locked with the same tread depth.
As far as riser height is concerned, you can't specify a default riser height. The program will try to figure out the best riser height to use based on the total height and the number steps you have. You can always override this for any given stair by just turning off the automatic heights and specifying the riser height you want to use. Please be aware that doing this means that you are then responsible for making sure that your stair actually reaches the next level.
One thing I did notice is that when changing the tread depth value (with the bullet for Lock Tread Depth" still selected), if I also change the number of treads from 17 (seems to be a default setting - I am using a 109.125 ceiling height) to some other value, and then click in the plan to place a new stairs, the number of treads for the stairs changes to back to 17. I then have to manually change the number of treads to what I want.
I guess I've never noticed this before and it seems like it might be something that should be changed but I think I'd want to play with it a little more to see why Chief makes it work that way. When I change the number of treads before closing the dialog, I can see whether or not the number of treads I have inputted makes the stairs out of compliance with the code mandated 7.75" maximum riser height. Seems to me like changing the number of treads as well should work as long as it is within code requirements.
It is my experience that the 17 treads is hard coded too , I tried changing it to 16 ( to get 7 1/4" +/- Risers default ) but the Program always switches it back to 17, so I have to open and change it anyway.... not sure if this is related to no default Riser being able to be spec'd.....the Tread Depth seems to hold though.....
Your findings seem to mirror mine. Not a real big deal to change the number of treads once you place the stairs. Seems like they could fine tune the coding to allow you to spec the number of treads. I won't be losing any sleep over that aspect of the stairs tools though.
True, it just another of those Time wasting things, that I personally think we should have control of in the Premier product..... I understand it in the Consumer software which is used mostly by HomeOwners, but not in Professional Software, with Users world wide, with Different Codes being applicable everywhere.
For stairs that need to be code compliant, I am still wondering why the min/max values you are suggesting couldn't be hard coded in the software. But, if other countries have different standards, then maybe that is not a good idea. I am reasonably happy with the way the tread depths and riser heights work at this time. I've got a hunch that there won't be too many users that will want to change this functionality of the stair tool ... but it never hurts to try. Maybe your ideas will lead to even something better as I think the stairs tools are regularly being looked at for improvements.
Very good Idea. I believe this can solve a number of issues. It would be even better if set up in the program default settings initially. It works for every country code requirements. The currently existing controls are quite nice. These suggested controls would be a guide or "deam to satisfy control". Thank you
That would be amazing but I don't think Chief has any intention of getting into that. However I agree that users should be able to set local code requirements in defaults or personal preferences above or below code.
For stairs that need to be code compliant, I am still wondering why the min/max values you are suggesting couldn't be hard coded in the software. But, if other countries have different standards, then maybe that is not a good idea...
To measure the offset of a comparator, I need a staircase funnction as shown in the figure. How can I generate this function in Cadence. I thought maybe with Verilog A, but I am not used to work with Verilog. For example, I would like to have a staircase function from 1.1V to 1.4V with step size 100 uV.
Verilog-A is the simplest way. Potentially you could have used an existing Verilog-A model for a DAC, and then maybe an ideal ADC to drive that, but then you need the right resolution. It's easy enough with Verilog-A.
You'd need to set minin to 1.1, and maxin to 1.4 on the instance of the symbol (use the "Use tools filter" to see the available parameters on the edit properties for the instance of the ramp generator), set the rise times of the steps appropriately (don't make them too sharp if your ramp is rising slowly) and then use a pulse source to clock the input - that allows you to control the rate of the ramp. Here's a zoomed in picture of the graph it produces:
We've made it super simple to add balustrade to your design - the new interactive staircase image allows you to simply click on the areas of the staircase you'd like to add balustrade to, with options for all balustrade styles including oak and glass. Our staircase design tool also shows a live "3D" staircase visualizer as you create your design, which updates with each click - You can now become an expert staircase designer!
Our stair designer has lots of useful features, such as the option to create new combinations of feature treads and the capability to design Open Plan staircases online with ease. It will also automatically alert you if you a design falls outside of building regulations.
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