I am building a new set of stairs off my deck. The run is longer than on the old stairs so I can’t just trace the old stair stringer. The rise and run of the staircase is: 9′ rise and 11′ run. How do I calculate the angles for the plumb and heel cuts for the new stringers, and the number of treads and the tread rise and run?
“enjoy what you do, do what you enjoy”
Renovations by Roger
Vancouver, Canada.
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Replies
Well, last time I did it I used BASIC, but now I'd use Java.
??????"enjoy what you do, do what you enjoy"
Renovations by Roger
Vancouver, Canada.
Typically I layout stair stringers with a calculator and a framing square.
Never had much need to now what any angle was, aint got a tool that'll give it to me acurate enough, 1 degree off in 16' makes for big mistakes in stairs. And I've never found a 16' 2x12 that was absolutely perfect.
I'd be interested in this angle method and does it save time and what tools do you need?
"The Stairbuildes Handbook" has tables for almost all rise run combos and a few options of riser height, mine is buried some where or I'd look it up for ya.
Walk it off with stair gauges set at about 7.5 rise and about 11 run and see how it looks, if it works out too short or too long adjust as needed ,in a pinch.
Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations.
That's a big 10-4 on the handbook. It has saved me a bit of time over the years. Just measure the space and look it up.
the pint sized green paperback is GOLD...mine is so old and dog eard it is about time for a new one.
Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations.
Yea, it's the short. floppy book.
Kiwi
Disregard what you read here, a gremlin must be in my computer!
Dont you think 9" rise is a bit much, you usually only go 8" max.
Do you have the room to make the rise somewhere in the neighborhood of 7 to 8 inches?
Doug
Edited to clarify my oversite!
Edited 8/23/2004 7:57 pm ET by Doug@es
no Doug, he means IN FEET ..overall, not treads and risers
Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations.
Ooooooh! I see Kemosabe
I saw the 11 and must have though 9"rise and 11" run.
I was going to write the same thing about the rise being a bit high, then I read Sphere's reply about the measurement being in feet. Ooops. At least the proportions were right. ;-)
The rise of the entire staircase is 9' not the step!! :-)"enjoy what you do, do what you enjoy"
Renovations by Roger
Vancouver, Canada.
Yea, your the third person to point that out!
I just put the 9 and the 11 together thinking rise and run.
I dont have the handbook, so this is how it can be done...
Plumb Cut: Inverse Tangent (tan^-1) of 11/9 = 50.71 Degrees
Heel Cut: Inverse Tangent (tan^-1) of 9/11=39.29 degrees
As a check, both angles should add to ninety degrees.
To get rise and run of individual steps I usually pull out the framing square and play with the numbers.
They're blowing a lot of smoke here. I think it's because your question covers a lot of territiory to be covered in a posting on a message board. Stair lay-out and building is something carpenters tend to take pretty seriously.
Here's what I usually do (in a nutshell). Use 2x12 stringers. Determine total rise and total run from finish deck to finish landing. Find uniform unit rises and runs that are close to 7" rise and 10" run. Use a calculator. All rises must be exactly the same (within 3/16"). Same for runs. We don't want any trip hazards here.
Make a pitch block. Take a square piece of plywood. On one leg, mark your unit rise. On the other, mark your unit run. Connect the two points with a diagonal cleat. Use this to mark your stingers. (This is easier than using a framing square unless you have those little screw-on thingies.)
Are you following this? If so, we can talk about cutting the stringers and then treads and noses.
Al Mollitor, Sharon MA
divide the total rise by 7
round off the number (up or down,whatever works)you get to a whole #
this # is how many risers you have
take that # and divide it into your total rise
this # is your riser measurement
use 10-10 1/2" for your tread length
put your framing square on those #'s and you have the angles
don't forget to cut the tread thickness off the bottom of the first riser
regards
You have a 9' rise (108")
You have a 11' run (132")
108/14 = 7.714286" or 7-11/16" (Rise)
132/13 = 10.15385" or 10-1/8" (Tread)
You have 14 Risers at 7-11/16" and 13 Treads at 10-1/8"
Tan-¹(7.714286/10.15385) = 37.22539° (Plumbcut) or 37.23°
Tan-¹(10.15385/7.714286) = 52.77461° (Heelcut) or 52.77°
Or 90-37.23 = 52.77
It's just like cutting rafters you have a unit rise and a unit run. If you have a Construction Master Calculator you can do this;
7.714286 [Inch][Rise]
10.15385 [Inch] [Run]
Press [Pitch] = 37.23°
Joe Carola
Edited 8/24/2004 8:04 am ET by Framer
dang man I figured it up before i saw your reply not trying to step on toes,
my const master say da same thang i even got that little pouch fer mine best
$65 i ever spent........ well its a close 2nd
Mike,
Gotta love the CMP but I have this bad boy for mine and it flips open and the blue part is rubber in case you drop it which I have it just bounces.
http://www.calculated.com/products/5012.html
Joe Carola
Joe, I have the same Armadillo case on mine.
Use a framing square to lay out stairs. Attached is M/S Word document I wrote for the Habitat for Humanity people that takes you through the process in a relatively concise manner.
Just the other day I built a set of steps for someone (they are attached to my current deck job). The old steps were 7/10 (rise/run) and the customer did not like them - said they were too steep. Generally, outdoor steps are not as steep as indoor steps are sometimes. The steps I built for them are 6.25/11.5, and they said they like them much better. See attached pics. They wanted them wide like that... I tried to talk them into 6' wide - they are 10'.
Edited 8/23/2004 9:06 pm ET by DIRISHINME
Check everything twice!
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LOL! Your is a little nicer than mine!
Joe you keep amazing me with the CM! Time to pull the notes out and jot that down!___________________________________________
Common sense is a gift from God that cannot be taught.
Erik,
Since your in Maywood and I'm in Caldwell maybe we'll get together for coffee some day and compare notes. Better yet when I go to help rebuild Joe Fusco(s) house you can come down on Rafter day and we'll knock it out together..........;-)
Joe Carola
Joe,
Sorry for the late response. I'm doing a fire job right now. By time I get home I'm beat and have to take 2 showers.
Since your in Maywood and I'm in Caldwell maybe we'll get together for coffee some day and compare notes.
LOL! Most of my notes are from you!
You talked about annoying your peers about framing when you were younger (not sayin your old) but I'd like ta pick your brain over a pot of coffee. Bastard valleys and hips are my weak point and a few other things. :c)
Better yet when I go to help rebuild Joe Fusco(s) house you can come down on Rafter day and we'll knock it out together..........;-)
It would be an honor and I'd look forward to it! I work hard and learn fast.
Erik___________________________________________
Common sense is a gift from God that cannot be taught.
Hopefully this will sound as easy as it. You need to know only the rise to start with. The run will establish itself once you decide how long to make each individual run. If you are using 6" wide steps(actually 5 1/2") , I would make each run 10 1/2". This allows you to have a gap between the boards and gives you a little overhang. If your rise is 9'(108"), divide 108 by 7.5" and you will get 14.4 steps. Since you can't have a partial step, figure either 14 or 15 steps. I will use 14. Now divide 108" by 14 and you have 7.71" or just under 7 3/4".
Now you know the rise and run for your steps, just a hair under 7 3/4" x 10 1/2". Now take a square and wrap masking tape around each leg of the "L", with the edge of the tape on one leg at just under 7 3/4" and the edge of the piece on the other leg at 10 1/2". Now all you have to do is lay the square on your 2 x 12 with the tape edges on the edge of the 2 x 12, and start marking them with the pencil. You'll see as you are drawing them out how to finish the top and bottom steps. The bottom step should actually be a little shorter than the rest( the thickness of the boards you use for the steps) or the bottom step will end up being that much higher. You'll figure that out I'm sure.
With the measurements I used here your total run will be 147", or 12'3" long. 14 steps x 10.5" .Once you do a set you can perfect it as you wish. When I do a set I find the exact rise by holding a straight board perfectly level from the top of the deck out to where the steps will end and measure down to the ground. You have to do a rough guess to narrow it down to how many steps you will need so that you know where the end will come. I know I don't explain things the best but I hope this helps! Good luck!
Duey
Those little books are ok, but if you want it to be a little more than ok, invest in a
CONSTRUCTION MASTER mine say;
for a 9' floor ht (rise) & a 11'length (run) you'll cut them on a 7 11/16 &10 1/8
you'll have a total of 14 risers and 13 treads
the total stringer length will be 13'-9 13/16" at an incline degree of 37.23277
but thats only if you want to be precise
school is in session most nights around 9:00 PM Jawja time
The angle is about 39 degrees. This is about a 10/12 slope on your speed square or framing square - for making the plumb cut. Shoot for about a 7 11/16 riser and a 9.5" tread cut. You should have ten inches for the tread, which can be achieved with an overhang of 1/2" beyond the width of the riser.
Thanks guys for all your help. I have taken your advice and used it to lay out the stringers and everything looks great."enjoy what you do, do what you enjoy"
Renovations by Roger
Vancouver, Canada.