I'm wrapping up another project here at home, and inadvertently came across a very odd building code. It's listed as r311.2.2, and essentially states that the backs of exposed treads/risers must be covered (drywall for instance). What's the reasoning? I'm in this situation, and while it could be done, I'm nearing the end of the project, and would like to avoid it at all possible. I know it's not a structural consideration, so what's the purpose? Should I be concerned?
I'm not sure exactly what you're talking about the "backs". But, commercially, you have to make sure the area under the stairs isn't accessible. The fear is.....in a fire, a child might go to that area to "hide".
Could be for a couple of different reasons: 1) Keep people from sliding through them and bodily injury such as broken arm or leg. young child from hanging themselves, or chocking similar to railing lattice needs to be a certain distance from each other 2) Keep items from falling though if kicked/dropped/etc and landing on someone 3) If you have an old house like mine, keep dirt and debris from falling and contaminating the air. My guess is that it's #1. Similar to how many bleachers are now.
Fire code. It's a preventive measure as fires tends to climb. Eliminating air flow between any two spaces reduces fires ability to grow at a much faster rate. Kill the air... and starve the fire. This applies to almost anytime a horizontal plane meets a vertical one in residential construction when passing between rooms/floors etc. Same reasoning as fire-caulking/plating anytime plumbing/electrical etc passes in between floors. Starve the fire of air on one level/room and it will be slower to get out of hand so-to-speak.
Does it say you can't have an open riser? Or, does it say you can't have an opening over 4"? What's a fire rated assembly look like for a residential stair with no riser?
All makes sense in an open riser design, but mine are closed. I found a contractor on a forun referencing this code even with closed risers. Is this accurate?
Can you copy/paste the code? If open risers are compliant, it's not fire code. And, I can't imagine how a closed riser wouldn't comply. Like I asked earlier.....is there a rated assembly for a residential stringer?
Not sure the link will work (if not, it's on page 255). http://books.google.com/books?id=id...Q6AEwAA#v=onepage&q=IRC code r311.2.2&f=false
What part do you see that's tripping you up (figure of speech) on compliance? You're in a single family dwelling (I assume). Also....open risers are compliant.
Any enclosed usable space under stairways in a one or two family dwelling or townhouse must be protected on the inside walls, soffits, and ceiling with 1/2 inch gypsum board. That part:D
So, you're gonna enclose this area? What do you want to do (what's the space's intended use?). That'll help.
It's semi-enclosed:D The inside stringer runs down a fully enclosed wall, the outer stringer (that faces into the room) is framed in and drywalled, but there is a ~3.5' access on the back that gives access to the under stair area. I'm planning on putting a few shelves on wheels for storage under there.
Now tell me what you're worried about. Did you pull a permit? THis isn't a big deal.....even if you have to come back in and do it later (I can't imagine why you would, though.....unless a home inspector picked up on it, during a sale). With the space not being enclosed, I'm not even sure it's required. Let's say you're sitting back a ways from the opening......can you look up and see the bottom of the treads/risers? Not worried about that for code. Just wondering how it looks, aesthetically. Who's checking (code compliance)?....and why?
No, there aren't any permits involved, nor am I having it inspected. The only concern would be, eventually, if I decide to sell the place, but as you said, I could always go back and "fix" it. My original concern is really only my anal retentiveness to making sure I do things right, even if they seem a little absurd and necessary. The underside of the stairs is completely invisible when standing back from the stairs. I will be posting pictures in a few weeks when I'm all done (don't have time to go through and upload them all right now).
As a contractor, I firmly believe in the building code. You can't decide what parts of the code you will leave out because it's inconvenient. For us it's against the law not to build to code - and I firmly believe in that law. But as a homeowner it is a good possibility that you are not bound by the building code unless you are in a code enforced area. With that being said, the code says that if you enclose the underside of your stairs, then you need the fire rated material (drywall), if you aren't enclosing it you can leave open risers.
I see what you're saying about being anal about things (i am too). But, I think as a homeowner doing a project like that? I wouldn't worry about that particular code all too much. And I don't see how it could affect the future sale of the home.JMO
