"donald girod" wrote in message
...
A house we are building (Habitat project) has the following basement stair
situation:

The total run of the stairs cannot exceed 115" because of headroom
issues--the state code requires minimum headroom of 6'8"=80 inches, and
there is a steel beam flange at 115" which is 85" above the floor. The
total height of the stairs is 103.5". With 13 steps, the rise per step is
7.96". There are 12 treads, and 115/12 = 9.58" run per step. The
building
code requires at least a 10" tread, so stairs with 12 treads, a 7.96 rise
and a 10" tread with about 1/2" nose would work (the nose of the bottom
step would project slightly under the beam but nobody is going to care
about
this).

However, these dimensions violate the "two risers + 1 tread = 24 to 25"
rule; you get 26, which is too large. My question: is a set of stairs
with
these dimensions going to be uncomfortable or unsafe to use? I know that
8"
rise and 9" tread works just fine (that's what my stairs are), but I don't
know how it would feel if the treads suddenly grew an inch.


I have a stairs to reach a storage area that are 9" run, 9" rise. I don't
mind them at all. I did not sweat code because they are not a stairs the
gets regular use.
In your case I would cheat a bit on the over hang of the tread like you
sugest. Your run is not 10" if you overhang the tread a 1/2", it is 9-1/2".
9-1/2" + 9-1/2" + 8" = 25-1/2". Close enough in my book when options are
limited.
The final answer will be your building inspector, if you have one. What does
he say?
Greg