how do you cut stairs the stringers whats the formula
Discussion Forum
Discussion Forum
Up Next
Video Shorts
Featured Story
Source control, ventilation, and filtration are the keys to healthy indoor air quality. Dehumidification is important too.
Featured Video
Builder’s Advocate: An Interview With ViewrailHighlights
"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.
Replies
According to code, the run (the tread) should be not less than 10"
the rise shouldn't be more than 7-7/4"
the generally acceptable rule is total rise plus run should be between 18" and 24".
When cutting your strings, don't forget to allow for the thickness of the flooring material at the top of the stairs, and cut that amount off the bottom end of the string.
According to code, the run (the tread) should be not less than 10"
the rise shouldn't be more than 7-7/4"
You mean 7-3/4"............;-)
IRC 2006 is Riser -7-3/4" and Tread - 10".
IRC 2006 New Jersey Edition is - Riser 8-1/4" and Tread - 9"
Joe Carola
Yup.
Guess I should read what I've typed before I post it.
rise/run
You want to aim for about a 7.25" rise and a 10" run. it will not bbe the same for every house.
start by finding out what is the rise from finished floor to finished floor in inches and divide that by 7.25
Suppose for example you are dropping into a basement with a slab floor that will not be covered with anything sso the distance in elevation from slab to finished floor on the main floor is 8'8" or 104"
When I divide that by 7.25", I get about 14.325 risers. I don't want an half riser. That will trip somebody up. So I round number of risers to 14, and divide that into 104" and find that I can build even set of steps with 7-7/16" risers. I know that will be safe and comfortable.
If these are in a tight location, and primarily a service stair instead of living space service, I consider using only 13 risers. That gives me an 8" riser size which is just a wee bit too steep for some localities and codes.
Do basically the same with the run. A section drawing to scale is a good idea, so you can make sure of your head clearance at the floor openning. You want 6/8" there from edge of tread. Some places might allow 6'6" or even 6'2", so you need to know your local application. If these are porch stairs outside, the headroom thing probably does not apply. It is better to use a run of about 14" for exterior though IMO.
When figuring the run, the cut in the stringer layout is not the same as the tread size. A 10" run will use a 11-1/4" tread just about right because of lip overhang when installing treads.
Finally, you will have to trim the bottom of this stringer depending on what you will use for treads. If using a 2x12, trim 1-1/2" off the bottom of the stringer. That drops top stringer enough that the finished tread surface is right in relation to the finished floors.
If you are using a 5/4 tread, drop the stringer by cutting one inch off. If you are using 3/4" plywood to be overlaid with 3/4" finished treads later, trim the stringer 1-1/4"
Welcome to the
Taunton University of Knowledge FHB Campus at Breaktime.
where ...
Excellence is its own reward!
thanks again for taking the time to write all that out I appreciate it
We always use the formula:
Twice the rise plus the run equals 25". i.e. (2 x 7.5) + 10 =25
I aim for 7.5" but the result is the same.
This means a shorter rise needs a longer tread to be comfortable.
Kurt
Now go cut some winders.
When you have an odd rise, like 12", that you will divide into two 6" risers, you don't want to stick with the 10" run. There are two simple formulas to use.
The first is that the rise plus the run should be between 17" and 18". So, with a 6" rise, your run should be between 11" and 12". 10" would feel like you were taking short steps and would tend to trip you up.
The other formula is that twice the rise plus the run should equal 25. Two times your 6" rise plus 13" gives you 25. Although that conflicts with the first formula, it tells you that a 12" run would be more comfortable than 11".
so how would you figure on cutting the stringer with those numbers
6" rise, 12" run.
Do you know how to use a framing square to lay that out?
no havent done it before but wanting to learn
The simplest way is to hold the framing square on the stringer so the "point" of the square is on the stringer, the ends of the square overhanging the edge. Assuming you're laying out a 6" rise, 12" run, line up the 6" mark on one leg and the 12" mark on the other leg with the edge of the stringer. Mark that triangle with a pencil, then slide the square down the stringer to lay out the next triangle. There are lots of tricks but that's the basic idea.
http://daveosborne.com/dave/articles/stringer.php
I just went out to estimate repair on a handrail. The stairs looked outa whack, and when I got the tape out, they were... tread depths: 8 1/8"; rise 7 7/8". Except the fist step with the rounded tread, (obviously bought and installed), it was 10 1/4" with 7 1/2" rise. !!! What a mess. There was NO room to install staircase with correct numbers, (total run) so they have to find another location to put in new stairs when they get ready to do so. Until then, I have to shore up handrail added as an after-thought. They toenailed newel post and balasters with finish nails all the way around. Wow.
In other words, free-market capitalism is the best path to prosperity.
Pictures please for the "How NOT to do it Thread'.
They can't get your Goat if you don't tell them where it is hidden.
If/when I get back there, I promise to do so.
“At its most basic level, capitalism offers people the freedom to choose where they work and what they do … the dignity that comes with profiting from their talent and hard work. … The free-market system also provides the incentives that lead to prosperity -- the incentive to work, to innovate, to save and invest wisely, and to create jobs for others.” -President George W. Bush
In other words, free-market capitalism is the best path to prosperity.
I hope you didn't attach the handrail to that post.
no, I had nothing to do with it! but if you pulled hard enough, it would certainly come off!! Nails all the way around...no bolts, screws or dowels.
“At its most basic level, capitalism offers people the freedom to choose where they work and what they do … the dignity that comes with profiting from their talent and hard work. … The free-market system also provides the incentives that lead to prosperity -- the incentive to work, to innovate, to save and invest wisely, and to create jobs for others.” -President George W. Bush
In other words, free-market capitalism is the best path to prosperity.
Too Funny!! I just read your Bush quote in the context of the situation you are talking about here with the stairs.
They can't get your Goat if you don't tell them where it is hidden.
no, I had nothing to do with it! but if you pulled hard enough, it would certainly come off!! Nails all the way around...no bolts, screws or dowels.
There is a VERY LARGE material supplier in Central New Jersey that supplies stairs and installs rails. They have maybe 20 installers working for them at any given time.
I installed for them for maybe three weeks. 7 of us were in the same development. AT lunchtime one of the guys came over and was laughing at me because I had dropped the post in the inside corner of a balcony run thru and used bolts.
He showed me his..................post cut and nailed on top of the landing tread.
His logic was that it would be held in place by the two rails attached to it at 90 degree angles.
Someday, when I retire from the Army? I'm gonna get rich putting new rails in 15 -20 year old houses all over New Jersey.
I'm thinking you'd have less liability if you just gave them a rope to hang themselves with on that one.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
actually, I was horrified to the point that I did NOT take pics, (I had my camera!!) and figured that if they want me to come back after they hear how much it's going to cost them, THEN I will get pics and measurements. I'm guessing they really don't want to address it correctly. In all fairness, it was that way when they bought it. I couldn't imagine that someone hadn't grabbed on to it while moving furniture upstairs!!! Amazing set up. If I go back, though, I will take pics.
“At its most basic level, capitalism offers people the freedom to choose where they work and what they do … the dignity that comes with profiting from their talent and hard work. … The free-market system also provides the incentives that lead to prosperity -- the incentive to work, to innovate, to save and invest wisely, and to create jobs for others.” -President George W. Bush
In other words, free-market capitalism is the best path to prosperity.
Ditto what our other learned voices have said.
Try to not go shorter than 6 3/4 rise, while you are at it (you really start needing 11" clear treads that short).
And the tread distance is "clear" in plan view, not from the face of the riser; and you really need some amount of nosing (where the tread above overhangs the riser below). Both of these address the placement of a person's foot on the steps, either ascending or descending.
BTW--most accidents on stairs are while descending per the insurance/actuarial types.
"BTW--most accidents on stairs are while descending per the insurance/actuarial types."
Damm Momentum and Gravity, time to get rid of BOTH!Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations
They kill Prophets, for Profits.
add wax to that list
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Momentum and Gravity, time to get rid of BOTH!
It's also Geometry and Anatomy, you want to get to cases.
Shape of the human foot and ankle geometry, it can be safer to back down stairs with awkward loads.Occupational hazard of my occupation not being around (sorry Bubba)
That too!
And while we're rebuilding the multiverse, bring back the prehensile tail!Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations
They kill Prophets, for Profits.
I refuse to live in a multiverse!
I had one of those. Couldn't lose her no matter what I did.
They can't get your Goat if you don't tell them where it is hidden.
Prehensile tail would certainly change handrail design (and fashions, male and female).Occupational hazard of my occupation not being around (sorry Bubba)
Forget that!
If I an gonna sport a tail, I want the whole thing!
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!