Stair Master Needed...

[westpoint]

Hey guys....we have a job at work on a set of stairs. We have prints but cant really use all the info on them. So, Im going to give you some info and if you need more just ask. The stairs are steel, they go up to a steel platform, and then 180 degrees go up again. Both sets are supposed to be the same....

Total rise: 80.25"

Total run: 101.75"

There are 10 steps that are 2"x10". The stringer is 12"x3". From the floor to the first step needs to be 8". The next 8 steps need to 7.25". Then from the last step to the top needs to be 6.5". Dont ask why, its just what it shows. It shows 10" from toe to toe of the steps. The steel will all be wrapped in wood at a later time.

I dont have prints for you to look at, sorry. We wound up using 36 degrees for laying out steps. The front of the step needs to be 2" in from the stringer and 1.25" down....im pretty sure. We came up with 129.5" for the diagnal, and 124.5" on the stringer cut length. Were using a square with degree holders attached during layout. Sorry if my terminology is bad, or spelling, lol. I only made a few set of stairs before and they were all constant so I could use my calculator. So if you need more info let me know, Thank you.

[Meltedmetal]

Haven't had my coffee yet this a.m. but what was your question? Does the designer of these stairs like to see people fall down? Cause the variable steps will trip people up. I'm not a stairmaster but I've never measured degrees on any stairs I ever built. Just layed them out with a square. Maybe a stairmaster will chime in. Good luck.
Meltedmetal

[Portable Welder]

I build alot of stairs and I never worry about what degrees the stairs are going to be.
You only need to know rise and run for the stringer layout.

I highly recommend you try to talk whoever it is out of making the steps with varying rises. People will be tripping and falling on the stairs.

I'm in Michigan, Residential steps are allowed to have a 8.25" rise, I dont know what the run is because I'm a commercial guy.

Commercial and multi family dwelling requires a rise of not more than 7", The tread is suppose to be 11" nose to nose with a 1" overhang so you need a 12" tread.
There is a variance for existing conditions.

What they very seldom allow is you to vary the height.

As far as stair layout, That is not something I can explain in writing.
You need to get a pencil and paper and draw them out.

I've seen brand new stairs tore because they were built wrong so you might want to check all your codes.

[Sberry]

I am not a stair master either but can agree this is a good place to make a screw up if there ever was one. I know a builder bud was mentioning to me in passing,, also in Michigan that rise was a matter of fussy concern and they were not very forgiving concerning codes.

[Bistineau]

I'm not a stairmaster either but have built some stairs. I would figure the total rise from bottom to top and divide it to come up with an even number for the rise on all the steps. It sounds like who ever designed it with a variation in the rise didn't bother to do this and tried to make up the difference on the last one. As has been pointed out, people will be tripping and falling with uneven risers, they all need to be the same. I say, ask if there can be a variance on the design to get all the risers the same height.

[concreteguy]

On these stairs, the angle to the rise /run given would be 38.26 deg. The rise would have to be 7 19/64" and the run would be 10 11/64". There is adjustments made at the top and bottom for tread thickness and also for floor finish adjustment. The code will only allow for a 1/4" in variance for the flight of stairs. If the stairs are off by a 1/4", but every stair is not consistent, expect to fail. More people fall on that slight variance than you might think. If they are calling for that and you didn't just mis-understand, walk away

[MMW]

First step 8" is most likely from the sub floor. Lay down 3/4" hardwood over the sub floor & it will give you the 7.25" rise. Same on the top step. Top step to sub floor is 6.5" then lay down 3/4" hardwood on sub floor & you get the 7.25" rise there also.

Just my guess.

[concreteguy]

Exactly

[Meltedmetal]

First step 8" is most likely from the sub floor. Lay down 3/4" hardwood over the sub floor & it will give you the 7.25" rise. Same on the top step. Top step to sub floor is 6.5" then lay down 3/4" hardwood on sub floor & you get the 7.25" rise there also.

Just my guess.

Had some coffee, That makes sense.--Meltedmetal

[Portable Welder]

The only time that my rise and run are not consistant is when I'm doing multi level stairways and there is a difference from floor to floor, In that situation there is nothing that you can do.