Calculating stairs

[BiGs]

Im having trouble calculating some stairs im fabricating, Im wondering if there is any calculater specifically for stairs. Ive layed it out in AutoCAD but when I built them they were wrong.... twice. Im getting really frustrated with stairs now and I have heaps more steal stair work coming up. I need a program that I can enter all variables like,stringer height and length, tread thickness, rises and goings etc and for it to work it all out for me, with tread templates etc. I found a program that does this exactly, but its $250. I want to see if there is another alternative before I buy. Can anyone help? (a calculator like the pipe mitre/notcher one would be ideal)

[lugweld]

Johnson Speed Square...You can do it all with your Johnson...That is their motto, not mine.

A speed square can do amazing things for you, laying out anything from rafters to stairs. Depending upon how you design and build them.

[tapwelder]

What issues are you having?

I use a framing square with the brass stops on them. Also, build stringers in pairs as mirrors of each other.

Really need more details.

[Knotbored]

http://www.blocklayer.com/Stairs/StairsEng.aspx
This page has an on-line calculator that would be useful to check your calculations-although its made mainly for wood or concrete it would work just as well for steel.-Free aint a bad price!
Also I googled "STAIR FREEWARE" and got lots of hits, although most are trial versions of costly software.

[framer]

Math is very important. It is simple as you know to divide height by number of rises.That
will give you treads also example 120"= 16 risers 71/2" equals 15 treads 10" to 12"
typically.I use feet and inch calculator by calculated industries a must for framers and stair builders. Where most problems happen is using framing square by the time you get
to last step you are probably long.If you take the diagonal of 71/2" rise 12"tread is 141/8".
Then calculate your steps 15x141/8"=2117/8" gives you a more accurate measurement.
So you can end where your supposed to.I will cut wood stringers first lay on plywood on
floor with rise and run.If treads or parallel with plywood your good.Use wood stringer on
both steel stringer. Works good for me. Framer

[farmersamm]

Gee, I haven't done it in years.

Used to figure the plumb cuts first to make the stringer. Rise and run.

Measure the height to the top of the landing, or where the stringer is to be attached to the second story. This gives you total rise. Next you do the math to figure out roughly how long to cut the stringer before marking the tread positions, and getting your plumb cuts.

10 feet from the ground to the top of the landing. Measure in inches and figure it out in inches.

Rise over run=7" over 11"

Start by using the square to mark the line where the bottom of the stringer will rest on the floor, measure from that level mark up the stringer 188.5"(this is the length of the top side of the stringer), then step up the stringer with the square to the 188.5" mark. One leg of square on 11" mark, other leg on 7" mark. Reverse the square (it'll be apparent how you have to hold it) using same 7 and 11 marks and mark the plumb cut. The step marks you made on the way up the stringer are the tops of the treads. Easier to show than to explain.

The algebra gives exact length of the TOP of the stringer. You can buy stock about 2 feet longer than that in order to allow for cutoff, maybe 3 feet longer. It's been a while since I did this. Practice in your driveway with layout lines, and you'll get a feel for it.

[farmersamm]

Oh BTW.. Brushing yer teeth regularly might help that problem

[William McCormick Jr]

Originally Posted by BiGs

Im having trouble calculating some stairs im fabricating, Im wondering if there is any calculater specifically for stairs. Ive layed it out in AutoCAD but when I built them they were wrong.... twice. Im getting really frustrated with stairs now and I have heaps more steal stair work coming up. I need a program that I can enter all variables like,stringer height and length, tread thickness, rises and goings etc and for it to work it all out for me, with tread templates etc. I found a program that does this exactly, but its $250. I want to see if there is another alternative before I buy. Can anyone help? (a calculator like the pipe mitre/notcher one would be ideal)

When I do stairs, I like to lay them out in Cadd. If you have no restraints in the run, and usually today you always do. It is easy, you just make up whatever rise and run you feel comfortable with.

But today usually the job is trying to get around the architects lack of forethought in laying out for the staircase. The run is usually illegal and anything short of tearing down the house will not help.

What I do is I draw a side shot of what I have to work in and with. If they are metal runners usually 10" "U" channel if they are steel, I draw them in with the clipped bottom and clipped top. I make sure I leave at least 36 inches to a wall at the bottom of a staircase. Usually 48 inches minimum in a fire escape staircase.

Then if they are getting poured pans, I draw in a single line level to the world, and a small upright the thickness of the pan. The top of this vertical line represents the front leading edge of the step. I then use a macro that places them evenly. I set the front edge in or back on the "U" channel the distance I want.

Usually what happens is that I draw the kicks and look in horror at the lack of tread or run. Ha-ha. And there is not a thing on earth you can do about it. It is just pure math. Ha-ha.

All the time architects will curse you if you just walk in and say no way. It has to be much more complicated then that or they are some real mean people.

Sometimes we take out a tread and to be honest the building inspector just does not care. He knows someone screwed up and its too late now. But that usually only adds a fraction of an inch to the rise and run anyway. So we end up with a 8-10 rise-run on a fire escape staircase.

They tend to frown on anything over 7 5/8" rise and anything under 10 5/8" run on a fire escape staircase. But over the years I have done some real off standard steps. No one cares or no one knows. Once we had to cut down a platform at the top of a staircase in a church. I really just wanted to walk off. Because if there was a fire and panic, that first step out of the chapel would be a doozy.




Sincerely,


William McCormick

[Gremlin]

I was taught that two risers and one tread should equal 25 inches , the tread meas.does not include the nosing.

[BiGs]

Thanks for all the info. That online calculator is designed for solid concrete stairs and is missing allot of variables i.e. goings, and would not meet Australian standards. but it looked promising.

Autocad can layout stairs but there is allot of room for error, also when I lay it out scale on concrete I have trouble. I ran into this http://cadtips.cadalyst.com/misc-use...stair-sections , but I cant get it to work with my autocad, somthing about adding lisp files or something. Its free and looks great, maybe someone could help me get this working?

I alsop found a 3rd party software program that only does stairs for $80, thats a bit better, but id rather get that autocad addy to work.

Thanks. -Ben

[BiGs]

Originally Posted by lugweld

Johnson Speed Square...You can do it all with your Johnson...That is their motto, not mine.

A speed square can do amazing things for you, laying out anything from rafters to stairs. Depending upon how you design and build them.

Originally Posted by tapwelder

What issues are you having?

I use a framing square with the brass stops on them. Also, build stringers in pairs as mirrors of each other.

Really need more details.

speed square and framing square is something ive never heard of, please explain!?

[BiGs]

http://www.shalla.net/ - a stair calculator in spreadsheet form. I will prolly try this next if I cant work out the autocad addy.

[gordfraser]

http://www.acehardwareoutlet.com/(rp...px?SKU=2189652

http://www.empirelevel.com/squares/f...FQsMGgodFHuJlQ

G

[lugweld]

I actually use a Swanson and a Johnson.

Here is the link to the Swanson. I think there is some usuable info there. Clcik on Swanson Tips and then on the right hand box it has a link for "stair layout".


http://www.swansontoolco.com/

[Ian-MetalSmith]

I use two excellent books on stairs that take most of the math out of the problem.

The first is Stair-Building by the American School of Correspondence in Chicago, don't try and find this book as it was printed in 1907. Yes, that is not a typo.

The second book is the Stair Builders Handbook from the Craftmans Book Company, printed in 1974. This is the stair bible for me. It has endless charts that gives recommended stair layouts for any given floor to floor height from three to twelve feet. It shows the ideal setup of number of treads, rise and run and a couple of options if you have a limited amount of space for the total run of the stairway. This is maybe cheating the traditional method but it works well.

Ian

[H2Os50]

If you are forced to have an "odd" step in the staircase due to having to only use a site specific rise and run or when installing pre-fabbed stairs, always, always, always put the odd step at the top of the staircase. If you put the "odd step at the bottom, people will always be falling down when they hit the bottom stair. Something to do with the way people expect to (unconsciously) go up or down stairs.

Just my 2 cents worth.

Butch W.

[tapwelder]

http://www.naamm.org/amp/pdf/18455_final.pdf

[BiGs]

Thats for the link tap, great info. I call the framing sqare a plate square, and ive never used a rafter square, ill look out for one.