Second Deck Question

[Jim Robinson]

I thought I had this information, but I can't find it. There are limitations to how far you can span with three 2x12 stringers, but I can't seem to find it. Anyone remember how far you can go until you need some mid span support for the stringers?

[Mark Reinmiller]

To answer the question we need to know what the beam is supporting. Floor joists framed in from one side or two? length of joists?

[Jim Robinson]

Rushed through that post. These are stair stringers. 36" wide steps, 3 stringers. Rise is about 8 feet. I didn't pull the horizontal span, which I probably will need. Probably about 12 feet with an 11" run. I'm thinking 11 feet is the longest, but I don't know where I had that number. Or maybe I just imagined the whole thing.

[Gunnar Alquist]

I don't remember a specific maximum span. The only thing I can think of is the total maximum rise of 12'. How did it feel when you walked on it?

[Jim Robinson]

I don't remember a specific maximum span. The only thing I can think of is the total maximum rise of 12'. How did it feel when you walked on it?

Mid range bounciness. Very tenuous fastening at the top, some toe screws - no blocking or brackets. Whole thing screamed homeowner built after getting the CO on the house.

[Mike Kleisch]

I thought I had this information, but I can't find it. There are limitations to how far you can span with three 2x12 stringers, but I can't seem to find it. Anyone remember how far you can go until you need some mid span support for the stringers?


Not sure if this is what you had, but the AWC has a 6 foot max span (cut stringers), based on the 2009 IRC.

See page 3:

http://www.awc.org/Publications/DCA/DCA6/DCA6-09.pdf

WI is looking at adopting this guide for their code.

[Jim Robinson]

That was pretty close to what I was remembering, except it's only about half as long as I thought. Not much southern pine here, so even six foot is more than it should have without a center support.