stratford1 wrote:
I'm building a set of stairs on my deck and CANNOT seem to find a
straight answer on this. I'm using closed outside stringers spaced 36"
and will use metal tread brackets to attach two 2x6 treads for each
stair. Some info I've found says I DO need a third stringer in the
middle for support...others have suggested I DO NOT need a third
stringer as long as my span isnt longer than 36". Any suggestions on
this? Will my 2x6s hold up ok or should I do the third stringer
regardless to make my stairs stronger?

My rule of thumb is that I don't leave a 2x6 unsupported less than
2' OC. If it were me, I would put in the middle stringer and be
happy with the stiffer stairs. If you want to eliminate the middle
stringer, then go with 2x12 treads.

Try this; take a couple of 2x4s and lay them down on some flat
concrete spaced 36" apart, outside to outside. Lay a 2x6 across
them cut at 36". Now step on the middle of the 2x6 and see if you
feel good about the flex. If you do, then go and get about 50 lbs
of groceries in your arms and step on it again. If you still like
it, ask your wife to step on it with you. If you still like it,
then go for the unsupported span. If you don't, add the middle
stringer.

--
Robert Allison
Rimshot, Inc.
Georgetown, TX