I am trying to figure out given a 9 foot ceiling height
on the first floor how long a staircase will be to the
second floor using a standard rise/run. Basically
I need to to see how long to make a hallway with
stairs in it to the second floor.
Thanks for your help.
You should go to the library and get a good carpenter book.
The basic answer is that a comfortable stair has about 7" risers
and 11" treads. There are other methods, such as 2 risers + 1
tread %". In your case divide 108" by 7" to find the number of
risers. Code restricts height of risers, I believe it is
currently 7 3/8" if your risers get larger than this, you need to
add another step. Find the total number of treads and multiply by
Keep the whole world singing. . . .
Shouldn't this be find the total number of *risers* (not treads) and
multiply by 11"? I'm no carpenter, but seems to me that you'd need to
know how many risers you'd need first to know how many treads you'd need
in order to multiply by 11 (and thusly be able to calculate how far the
staircase will extend), no?
Or maybe I shoulda just learned my lesson from the ice dam and furnace
working harder topics and shut up ...
No, that's not. Dan said (generally) risers are 7" and treads are 11".
He gave the math to calc the number of risers (108"/7"), but not how
many treads would be needed according to that calc that in the end gives
you the total length of the staircase. He simply said "find the number
of treads and multiply by 11." Under that instruction, he didn;t give
any calc on *how to find the number of treads*. Seeing that he said
multiply 11 (instead of 7), I naturally assumed he meant to write riser
instead of tread but got himself reversed while writing the post.
Maybe it didn't confuse me because I can build steps. Now, the 108/7 _will_
be the number of treads, depending if you want your first tread starting
even with floor . You find the number of treads exactly like he said,
depending how you want the first tread to fall. Then you multiply exactly
how he said. You multiply the run (tread width) by rise, exactly what he
said in answer to the OP's question of " I need to to see how long to make a
stairs in it to the second floor."
Make that you need yet another cup of java.
I wasn't confused the first time around, since I know that the number of
risers you have will give you how many treads you'll have. I'm not
*that* retarded. It was the wording of the very last sentence (Find the
total number of treads and multiply by 11") that I raised an issue
about. I thought the *way* he worded it *may* confuse people who don't
know how to build stairs because he didn't make clear that the number of
risers you get automatically provides you the number of treads with
which to multiply by 11" or whatever depth you want your tread to be. He
simply said "find the number of treads" without saying that you've
already found it with the number of risers provided by the "divide by 7"
You said it in your post here, but Dan didn't make this clear in his
original post, IMO.
I assumed . . . . . . .
A prudent person would make a sketch of the situation. I gave the
correct method of determining the number of risers required.
Make a line on a piece of paper to indicate the floor at the
bottom of the stair. Make another line to indicate the floor at
the top of the stair. Make the sketch with the number of risers
that were calculated. The number of treads does not necessarily
equal the number of risers. It will be totally dependent on how
you tie in the top and/or bottom.
From the sketch determine the number of treads that you will need
to complete the stair as sketched. Multiply by 11" or whatever
tread dimension you chose to use. If you are cutting the
stringers you will need to do a lot more figuring. You will need
to know tread depth, finish floor treatment at top and bottom. As
an example, if you are looking at subloor dimensions before
completing hard wood flooring, you will need to adequately
consider this information in your calculations. Code will also
require that you create an "even gaited stair" We have all
stumbled on stairs with an odd ball riser at top or bottom.
Hope this made it more clear. I repeat, pictures are worth 100
words. Go to the library.
On a wild googlechase I found this:
Keep the whole world singing. . . .
Another minor correction:
After you figure the number of treads and determine the tread width, say 11
1/4", than multiply the number of treads by 10, not 11 1/4. This would be
the run since there is a 1 1/4 overhang.
As state below, dived the height (rise) by 7 this will give you the number
of risers. (don't use 108, this is to the bottom of the ceiling you need to
the top of the 2nd floor).
Depending on how you build the stairs you will have either the same number
of treads (runs) or one less.
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