10" tread boards okay for staircase?

[Sasquatch]

What do you guys think about 10" tread boards and seven-and-three-eights-inches for the riser boards on our staircase? The rough opening for our staircase on the second floor is off by 3 feet. The mistake was made by the truss company that designed our floor truss systems, and nobody caught it until after our staircase was built. Among other necessary changes (see our blog for details), this caused our staircase tread boards to be only 10 inches. This is allowed by code, but it is not exactly a luxurious size for the steps. What do you guys think? Is 10 inches too wimpy and cramped? Here is a link to our blog article where you can find a drawing that shows the newly rearranged second floor. All feedback is greatly appreciated.

[Shannon Pate]

If you are adhering to the 2003 IRC, you may not be in compliance.

If, by 10" tread boards, you mean that the stair stringers will be cut with a 10" seat, then you'll be fine. But if you mean the actual place where you put your foot will only be 10", then you are in violation.

The language on this one is tricky. The codes say that a 10" minimum tread is required. However, it says two things that are going to hang you up. It says that treads less than 11" must have a nosing. It also says that the treads are to be measured from the foremost projection of adjacent treads. Therefore, your 10" step must have a nosing (I think the minimum nosing is

3/4") which will bring your measurement between the foremost projection of adjacent treads down to a maximum of 9 1/4" which is a violation.

I don't know why they wrote it this way, but the bottom line is the level cut of the stair stringer must measure at least 10" without adding any tread.

If no ones inspecting, I say go forward. Until the IRC was adopted around here we cut stairs on 9" with a 1" or 1 1/2" nosing all the time. In fact, thats what was in my last house and I never once fell and broke my neck...go figure...

Shannon Pate

[Pat]

Okay, I'll say it before Don does: The truss company read the plans wrong, missed the stair opening by 10 FEET, and you trust them to hold your house up???????

The good news is that you want your house to look "old" and a steep stairway is definately old. So that's good. The bad news is that they changed to a larger stairway for a reason.

[Shannon Pate]

I've looked at your plans and photos.

If I were building your house, I think I could find a way to fix it.

Post a picture of your engineered floor layout for both floors.

In the photos, it looks like the first floor stair opening is ok.

The problem is that the opening for the second floor stairwell should be 4' from the front of the house. One side of the stairwell is a bearing wall, so you could cut the I joists on that side with no problem. The other side should have a beam with joists connected to it with joist hangers like the downstairs stairwell.

So, you cut the joists on the bearing well and add a rim joist. Then, after supporting the I joists on the other side, you remove the beam with the joist hangers (I can think of several methods that would work). On the same side as the beam, cut the I Joists needed to install a longer beam. Then, install the longer beam, reattach the joists with joist hangers

Then, cut a new set of stringers with a minimum tread (cut) of 10" and a maximum riser of 7 3/4".

On those risers, don't forget to consider the thickness of the finish material at the top and bottom of the stairs, and the thickness of the finish tread.

Shannon Pate

[Sasquatch]

What is "2003 IRC?" Does that apply hear in Wisconsin?

When I measured the tread board, it was 10" from the face of the riser to the edge of the tread board. So the part I put my foot on is 10". There is a nosing, which hangs over somewhere between 1/2" and 1" but I didn't measure that so I'm not certain.

- John

Shann> If you are adhering to the 2003 IRC, you may not be in compliance. >

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[Ken S. Tucker]

"""The bad news is that they changed to a larger stairway for a reason."""

Yup, a couple years back I slipped going down stairs, stupidly I was wearing loose slippers on size 12 feet, but the stairs were dinky size. Ken

[Shannon Pate]

I did some searching online.

It appears to me that there is a statewide adoption of the UDC codes in Wisconsin. Once I learned that, I did some googling for stair codes in the UDC. I found a UDC commentary which had some interesting information. Here is the link to the commentary located on the Wisconsin Department of Commerce website followed by the exerpt:

(c) Tread depth. 1. 'Rectangular treads.' Rectangular treads shall have minimum tread depth of 9 inches measured horizontally from nosing to nosing.

There is a notice under the commentary that says that all changes from January 2005 were not included, but provides information on those changes. In that document, the only stair related entries regarded the spacing of spindles and such.

You can easily find all your answers tomorrow by calling the buliding department listed on the building permit.

Shannon Pate

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[Don]

If you said 3' and not 3", thats not acceptable. The truss companies require someone to sign the truss layout PRIOR to fabrication of the trusses. I'm one of those rare birds that does complete component design on all of my plans, leaving nothing to error by nitwits working for minimum wage. So, yes the truss company made an error but someone in the chain of command under your employ ACCEPTED that error. I say, rip it out and make it like its supposed to be. You see, a stairway starts as a big hole in the 2nd floor and the entire perimeter of that hole must be supported by the floor below. This is all calculated out on the plans to transfer the loads to the footing. If the hole moves, as you've indicated, then the loads are transferred accordingly and a structural failure may occur. At the very least, stop construction right now and consilt with the original design professional that prepared the plans. If you don't do this right now you may very well pay much more later to correct this thing.

[Sasquatch]

Yeah, it is unacceptable. Truss company produced an incorrect design, but that was because they were given incorrect information, and then on top of that our builder didn't notice the mistake until the floors were in place. Definitely a case of human error. But mistakes happen. As long as it's fixed, I'm happy. We came up with a work-around that allows the builder to use the existing floors. In some ways it's better, because now the staircases are properly stacked, whereas before our architect had cheated the stair cases, staggering them forward and back for less headroom. Now we have more headroom going upstairs and downstairs. And we have a safer landing upstairs. And they're redoing the staircase so that the tread length meets IRC code, including 11" tread boards, and 3/4" overhang, for a net tread length of 10-1/4" which is 1/4" better than code. The rise is still 7-3/16", which was already fine. We're just losing a little bit of our extra walk-in closet upstairs. I can live with that. Better than ripping out LVLs, sawing off the ends of engineered joists with a sawzall, etc.

Here's a link to our compromise design:

All the bedrooms have dimensions that are minimum 11+ feet, and most dimensions are 12 or 13 feet, except for the spare bedroom/nursery, which is 10' 6" by 12+ feet. Closets are generous with 72" bi-fold doors. All hallways/landings/staircases are sized comfortably, too.

What do ya'll think?

- John

D> > What do you guys think about 10" tread boards and

[jojo]

reverse the swing on the front left bedroom door and you've got it!

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[Ken S. Tucker]

Nice observation you all...:-) Ken

[Sasquatch]

Done! Here's the latest version.

Thanks. I missed that. But clearly we want it to swing the way you recommended. Good catch.

- John

jojo wrote:

[Don]

Say what?

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[Don]

That door currently swings up against a small wall that is useless for furniture as it is in the path of the walkway. If the door swing is reversed it will take up more space in an otherwise small room and cause issues with furniture placement. Unless Jojo is talking about swinging the door out into the hallway which is totally unacceptable. As it is is the most efficient way of doing it.

[Ken S. Tucker]

Guy's and Gal's, I dislike bi-fold doors. Sure they could save a bit swing space but at the expense of running over a toe, I've used them but only as a last resort, oh and the're finger pinchers too. I'd go sliders, either a pair of mirrors, or nice looking stuff, and if you need to completely open a closet, use accordions or an attractive curtain. I used a curtain with a soft red light in a wide closet, makes a nice warm glow and is ideal as a night light, so you can get up and pee. Ken

[Ken S. Tucker]

As I understand the thread, Jojo suggested a door opening revision that became this...

that Sasy subsequently posted, looks good to me too for the reasons you specified. Ken

[JD]

What?! The bedroom doors all have proper swings.

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[JD]

????

[JD]

I'm confused. Was the image updated after Jojo's post?

[Don]

Then I guess I missed the pic with the wrong swing. The pic above looks fine to me.