We have been eaking out the last bit of headroom under our open riser stairs (still working on the sketchup). We are doing a 7.75 risers with a 9" tread (it's a modification in our code - IRC is 10" min tread). We'll do 2 treads - then a landing - then 10 more treads. So the long stringer will span 10 x 9" = 90".
THe question is can I use 2x10's instead of 2x12's for the stringers? Should I use more stringers? 3? 4?
Let me know if you need more detail.
Thanks!
Use 2 x12's , we space them no more than 12" apart and use 2 by tread material , YMMV.
QuoteUse 2 x12's , we space them no more than 12" apart and use 2 by tread material , YMMV.
In the loft we're spanning almost 4' with 2x6 t&g, but here we don't even go the 18" to the edge of a 36" stair? Is there something more than the deflection working in the center of the stair? (This is actually what I was thinking when I asked if I could go to 2x10 - add another stringer to take some of the load.)
So PEG. How about 4 2x10s ;)
Also, would it help to not notch them? Something more like this (https://i63.photobucket.com/albums/h132/dmlsr/100_1258.jpg)
One thing that is for sure there's ALWAYS another way . I'd call that a ladder not a stair system. ;D
Spanning 3' with a single 2x6 or even 2 x12 is two far IMO . Stairs can and do get big loads placed on then , furinture , appliances , groups of people passing , etc .
So IT DEPENDS on conditions not in evidence / presented / admitted to / revealed.
I answer questions based on what is "normally done " , there are exceptions and wide / strange / odd / and just wrong that people do every day . I can't cover all those variables in a short answer , given 1/2 or sometimes less , of all conditions .
That one is definitely a ladder.
I wasn't complaining PEG. You did a good job answering my question. I was just reaching/grasping ;) Trying to understand the forces at work.
2x10s would be fine as long as you don't notch them.. Perhaps you could beef up the treads to make the 3' span without a third stringer? Maybe you could go for more of a timber staircase.. 4x10 stringers and 3'' or 4'' treads or something like that.
Yes a timber stair could work , either with the bracket shown in your photo , or a trapped tread routed into the stringers . Heres a recent thread from Wooden Boat Forum on stairs like that.
http://www.woodenboatvb.com/vbulletin/upload/showthread.php?t=66459