What went wrong with stair case construction ?

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Old 04-19-16, 01:03 PM
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What went wrong with stair case construction ?

Spent the last two weekends demolishing and building a nice 12x16 deck at full size vacation/weekend mobile home of ours. We opted to build a recessed staircase to give ourselves more room in the driveway. So I spent some solid research time on Saturday getting all my numbers right (supposedly) for my stringers.

I test fit them...had scab wood available for mocking etc. Somehow still completely messed them up.

My total rise needed to be 33.5 inches and we are using two 2x6 for the treads. Came up with 6 and 11/16ths rise on four steps with run of 11 inches each.

I wanted to use 2x6's as the treads and to cover the risers, so I mocked this all out on my stringer setup and thought I was good. I have attached an image that I think spells out where I went wrong. Ultimately the run of the stringer is way too longs, which makes me think I can take them off and adjust down.

Ultimately both my rise and run are off. The run was obviously a gross miscalculation on my part. The rise, well, not so sure what happened. I wanted to bolt the stringers into the joists, so I just made an extra step on each one. The problem I think is that I failed to realize that a 6 and 11/16ths rise wouldn't cover the 2x8 joist cap at the final step. So my last step is more like 7 and 1/4 inch. Frustrating. So maybe my total rise is infact 34 inches and not 33.5?

I am not there right now so I can't re-measure. I just get to keep racking my brain at home until I can get back up there, rip it apart and fix it!

Anyways, there are four stringers. Is this something you would try to modify the stringers and make right or should I just start over and cut four new stringers?

Also any tips here would help. I think I perpetually confuse run and what I want my physical tread length to be and it screws everything up. I have attached an image of the staircase as we left it for good measure. We screwed the boards into it with big gaps just so we could safely go up an down while we continued to remodel, but I am probably heading up tomorrow or Thursday to fix!

Actually as I post the deck picture, I can see the total run is three and a half to four inches too long, as the post I scabbed in there is outside the edge of the house. So writing this post has even helped me realize my errors.


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Old 04-19-16, 01:38 PM
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For a low deck like that, you could have bought prefab stringers. BTW, your text said 2x6 stringers & the diagram said 2x8.
 
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Old 04-19-16, 02:07 PM
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The joists on the deck are 2x8's. My wording on the diagram may be confusing...what I am trying to point out is that the stringers are mounted to the inside against the 2x8 joists.

The 2x6's being mentioned are the boards I am using for the tread on the stairs. The stringers were cut from 2x12's.

In theory I could still buy pre made stringers since I am most likely going to redo it. The problem I have with pre made ones is they never seem to have the numbers I need for my application. Like in this case...where can I find a premade stringer with 6 and 11/16ths rise?
 
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Old 04-19-16, 02:23 PM
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IMO, the top of the stringers should have been mounted against the rim joist. The risers & treads are calculated from there.
 
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Old 04-19-16, 02:42 PM
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Yes I think trying to mount it inside the joist certainly contributed to the demise. I think I would have needed to notch it or something.
 
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Old 04-19-16, 03:19 PM
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You didn't have to notch it either. The entire edge of the stringer should rest against the rim joist.
 
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Old 04-19-16, 03:40 PM
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I meant notching the stringer as it currently sits, mounted inside the joist. I think if I would have notched it in that situation, my final rise would have been adjusted properly.

I guess I am not seeing what you are saying. The rim joist basically represents the rise of my final step. So if I wanted to mount to the rim joist I think I would need to hang another 2x8 below that and I could attach it with hangers.
 
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Old 04-19-16, 03:49 PM
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The rim joist basically represents the rise of my final step.
It may only represent a portion of the rise not all of it. The tread doesn't have to be at the bottom of the rim joist. Does that make sense?
 
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Old 04-19-16, 04:02 PM
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You want to determine your rise from the top of the deck to the spot the stringer will meet the grade... the front edge of that first step. Lay a long board on your deck, letting it hang over a ways, then measure down to the ground way out where that spot is. You generally want a concrete pad or pier for the stringer to set on so that it does not sink into the ground. the pad / piers should all be level, so that your stringers sit level.

If your rise is correct, at 33.5", then use a framing square to mark the cutouts on your new stringer. Line up one side of the framing square at 6 11/16", and the other side of the framing square at 10". Then mark the outline of the framing square. The run that you mark is 10" because you will have 1 1/4" of nosing (per code) after you apply the treads. Mark out all your steps this way, making the rise and run exactly the same on each. When you get them all marked out, make one more mark... you need to cut a additional 1 1/2" off your first riser. Basically, your first step is cut 1 1/2" shorter than the others, because once you put the treads on, they will then all be equal. I know it's confusing, but believe me, this is what you need to do.

If you don't have them, buy some brass stair layout stops for your framing square. Makes it super fast and easy and once you get the stops set, all your stringer layouts will be identical.

http://www.amazon.com/Johnson-Level-.../dp/B00002NBKH
 
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Old 04-19-16, 04:29 PM
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It may only represent a portion of the rise not all of it. The tread doesn't have to be at the bottom of the rim joist. Does that make sense?
Sure does, I just worry that only about a half an inch to three quarters of an inch of the back edge of the stringer will make contact with the rim joist. Right now the run of the final step is flush with the bottom of the rim joist, and with the tread screwed in, the rise is about 7.25 inch, so it needs to come down a little over half an inch to be within spec for the other steps. That would then represent what would contact the rim joist if I start over.

Then mark the outline of the framing square. The run that you mark is 10" because you will have 1 1/4" of nosing (per code) after you apply the treads.
Okay but what if I want to cap the risers with my 2x6's? Trying to work that into my original math is what screwed everything up.

At ten inches if I put two 2x6's and then cap the riser with another 2x6 I end up with the riser cap sticking out a quarter of an inch...so it seems I would need to reduce the run to 8.5 inches to account for a 2x6 face on the riser?

I guess the riser cap just becomes part of my run and I keep overthinking that.
 
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Old 04-19-16, 04:31 PM
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Do you know what nosing means? I know you are using 2x6's. You will not have 1/4" nosing, you will have 1 1/4" per code.

Please just do what I am suggesting. 6 11/16 and 10". This is not as hard as you are making it. You do not include the nosing in with the run.
 
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Old 04-19-16, 05:29 PM
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Nothing you are telling me indicates what I should do to enclose the rise of my steps.

If I put two 2x6's on a ten inch run, that is going to leave me one inch of nosing. Put a quarter inch gap in between the treads and we end up at an inch and a quarter of nosing which is what you are indicating.

Now, if I then put another board across the riser, my nosing goes away. Nosing to me means the front of the tread hanging over the front edge of the run.

So, explain to me how your way accounts for me putting a 2x6 across the front of the riser?

Your method sounds perfect if we weren't going to enclose the staircase.
 
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Old 04-19-16, 05:42 PM
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XSleeper - Okay, just went to the garage and sketched a few things on a scrap 2x12.

Now I see the light, numbers are good, thanks again!
 
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Old 04-19-16, 05:43 PM
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Your drawing is pretty good, so I would think that if you added some measurements to it, it would become clear to you.

When you cut the tread on the stringer 10" wide... then put a riser on the riser above... and put a riser on the riser below, guess what? The distance from the front of one riser to the front of the next riser remains 10". When you apply your treads, your two 2x6's, which have 1/4" of space between them, you have 1 1/4" of nosing and an 11 1/4" tread.
 
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Old 04-19-16, 08:31 PM
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Yeah... just took drawing it out and actually seeing it.

Now, do I try and modify the stringers or just make new ones. Probably easiest just to make new ones. I have to double check and make sure my rise really is 33.5 and not 34...don't want to do this three times.
 
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Old 04-20-16, 09:20 AM
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Stringers

Use 2x12's for stringers. When using 2 2x6's for treads, cut the run at 10 inches, which gives a 1 inch overhang on the front, referred to above as nosing. The risers go behind the treads, not on top of them. I did not read all of the details from posts above. If all of this has already been covered, I apologize. Good luck with your project.
 
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Old 04-20-16, 11:27 AM
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Okay assuming my rise remains 33.5 inches, I am still unsure the best way to connect the new stringers.

In my head if I want to mount it flush inside the joist I'll need to make a little notch on the top run.

Or, as pulpo suggests I just go straight into the rim joist, but then I have only a small part of the stringer making contact.

Image attached. Suggestions?




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Old 04-20-16, 11:44 AM
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Put a 2x12 backer on the back of your rim joist, so that it hangs down farther. Then your bottom picture will be close... cut the stringer plumb, even with the back side of your rim joist. It will butt up against the 2x12.
 
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Old 04-20-16, 01:01 PM
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Okay perfect thanks again.
 
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Old 04-20-16, 02:56 PM
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Stringer

If you are cutting new stringers, make the very top, horizontal cut flush with the top edge of the rim joist. Fasten through the inside of the rim joist into the stringer. When you do this, you will need an additional pair of 2x6's for the top tread.
 
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Old 04-20-16, 04:09 PM
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Wirepuller, I don't think he wants a tread flush with the top of the deck. His deck has a picture frame perimeter that already has nosing. It would also affect the handrail.
 
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Old 04-20-16, 08:52 PM
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Yep, exactly right. Trying to avoid extra treads at the top. Thanks again everyone for the advice...I'll post a pic once I have redone it.
 
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