Footings with beam for wide deck stairs?


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Old 03-31-16, 02:21 PM
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Footings with beam for wide deck stairs?

Hey all,

I'm getting ready to build the stairs for my deck and I have a question I'm hoping to get some assistance with.

The stairs will be ~8 feet wide, but only 2' high.
The DCA6-9 mandates that where the stairway meets grade, the stringers must rest upon posts, which in turn rest upon footers. Although it doesn't state this, I'm assuming it's expected to use a beam to span the stairway footings and not dig a footer for every stringer, since that would be insane. In this case I'd use 2 2x8's ripped to appropriate height.

I don't want to use box steps, due to the grade between the deck and the landing.

Anyway, if you have any input I'd appreciate it.

Thanks in advance,

Rob
 
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Old 04-01-16, 05:48 AM
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Just to clarify my "footer for every stringer" comment, I forgot to add that I'll be using 5/4x6 IPE which allows a 24" span between joists/stringers, so I was only going to have 4 stringers, spaced every 2'. I was hoping to dig as few footers as possible since the ground is full of rocks. Looking at the code shows a max distance of 36" between footers. If I stick with that, it looks like I may be able to get away with using just 3 footers if I drop one in the center and 2 more 36" in each direction and have a 12" overhang on each end if that is allowed. This would work since I'm not installing guard rails for the stairs. If the ends need to land on a footer I'm back to using a footer for each stringer.
I haven't seen anyone use a beam to secure the bottom of the stringers, but don't see why that wouldn't work either.
 
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Old 04-01-16, 06:17 AM
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I'm a painter, not a carpenter but I'd think you'd want a footer/pad all the way across for the bottom of the stringers to rest on.
 
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Old 04-01-16, 08:58 AM
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Thanks for the response and suggestion, marksr. From what I've found, pouring a slab is what most people have been doing. However, according to the Deck Construction Guide, this is not supported unless the slab is poured below frost level. "Stringers shall not bear on new or existing concrete pads or patios that are not founded below this depth."

I know I don't have to follow the DCA, but I think they have a point regarding the need to attach bearing stringers to footers below the frost line, which is 30" where I live.

I still feel that a beam solves for all problems. If you can build stairs that work within the same building parameters as the deck itself (regarding spacing for footings, joists/stringers, and beam spans) I think they would work just fine.
Two footings and beam. Easiest and very sturdy.

Here is a link to the DCA62012: http://www.awc.org/pdf/codes-standar...Guide-1405.pdf

Comments/suggestions very welcome
 
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Old 04-01-16, 11:20 AM
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If you pulled a permit and are getting it inspected, then discuss with the AHJ. Certainly your suggested approach is structurally sound and probably will be stronger than 90% of the deck stairs out there....

As Marksr said, most of the time folks pour a small pad for the steps to land on.
 
 

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