Winder Stair Code Diagram
Chanelle Kirksey
I can see the BI point about the 6". If you are carrying something in your hands and cannot see your feet or the steps, and step into that small area it becomes a ski slope.Your foot will slide to the next step causing you to fall backwards in most cases.
I used to work for a shop where we also built the York spiral staircase, Although these are very attractive, you better have another means of moving furniture. Running up or down will get you some sore bones. Better than a fireman's pole and visually stunning but not what you want for a main stair.Beat it to fit / Paint it to match
IRC code calls for 6" min. at small end of tread and min. 10" at a point 12" in, which is the walk line. Now, my local code calls for the 6" min. at small end, and at the 12" in, walk line, depth of tread should be same as the straight treads. But if they are all winders as in a curved ( circular stairs ) then the 12" in measurement should fit into the rise/ run code here , which is 2 rise and 1 run = 24- 25". As far as the balusters, yea you may have to fudge a bit, but still stay within the 4" code.
My thought is that if the small side of a winder tread, was, say 2" wide, and someone was hurriedly ascending or descending the stairs and stepped on that 2" "ledge" their foot may likely slip off and they would fall down the stairs.
As far as BI's not measuring stuff, you are right, but although I hate to admit it, those guys are pretty sharp: I've had one say "hey, that baluster space is more than 4". So I produce a tape measure, and find that it is 4.25". In my area, they do maybe 10 or more inspections a day, so even after only a few months on the job they can almost spot things from the street... Not to say they don't miss things, but generally I find these guys extremely quick to pick up on the discrepancies. I always try to walk my jobs with BIs - especially for the framing and final inspections.
I work for an achy/builder who is always squeezing in winder stairs. His record is 7 winder treads in one flight! It's interesting that the rest of the country has a 6" minimum for the narrowest part, while NC has had 4" for as long as I can remember...at least since last week, ha.Up until we went to the IRC, we could put the handrail on the wide side, way easier and better looking, IMO...good thing the rail can run fron 30-38" in the same flight "But to be honest some folks here have been pushing the envelope quite a bit with their unnecessary use if swear words. They just put a character in to replace a letter. But everyone knows what they're saying." Sancho
BTW I called the NC Dept of Insurance/Firemarshal office in Garner to try to get a new code book so I could get a jump on the new code. The lady told me that the new code books are not yet available, but that the "new" 2006 code would definitely be adopted in July - same thing I was told a year ago... :-) I am very interested in finding out about the new code requirements because I have some house plans that may need to be redrawn because of the stairs.
OTOH, looking at this document form the NCDOI I think I might be OK and it might be safe to assume that if changes are not listed, then whatever the IRC 2003 specifies might well be what we have to build to. If you look at the afore mentioned document, the stair section starts on page 31, although only the modified paragraphs are shown. You probably know this, but the underlined sections are what NC added. Obviously the strike throughs is what NC is removing. So, it looks like, for the most part we will still have our somewhat liberal stair requirements.
BTW - regarding continuous stair handrails someone told me that they are going to start enforcing it so that we have to have continuous stair rails like what is shown in Photo 23 of this document that I referenced earlier in this thread. Does your building jurisdiction inspections dept enforce that? What are you? - Chapel Hill/Carboro/Orange Co/Durham? I build in Raleigh/Wake Co/Cary/Garner/etc and they don't make us do that. A carpenter told me a few weeks ago that he thinks it sux because it makes the rail assembly less strong. What do you think?
Name only changed to protect the innocentDoesn't look like anything relating to stairs changed at all in the new IRC.Add Chatham to my range of counties...as far as the continuous deal, there's an overlapping clause that I've asked a few inspectors about, haven't ever gotten more than a "what the hell does that mean?" shrug out of them. Nobody's ever seen an example.I haven't actually had to do that jog you pictured, might be a little less strong. It would still be fastend with wall brackets. Take a while longer, though. Our inspectors are usually pretty accomodating. When we have an issue with handrails, we'll discuss it with the clients, then call inspections for "advice." They usually give the "well, if that's what you really want to do" variance.Hey, I'll have to meet you over at Irregardless for lunch sometime. Or come over here, and we'll get Shelter Nerd to spring for some pizza "But to be honest some folks here have been pushing the envelope quite a bit with their unnecessary use if swear words. They just put a character in to replace a letter. But everyone knows what they're saying." Sancho
Irregardless for lunch sounds great - it's only about 3 or 4 miles from my building site. Or I could come over your way but it would have to be Saturday. I'm slammed Monday - Friday, and actually usually work 1/2 a day on Saturday, but that's flexible - I only do it because I like my (salaried) job and Saturday is a day when I can get some stuff done uninterrupted. I'm sending you an E-mail. All these years at BT and I've never actually met anyone - OK - maybe one, but he was a short-timer that isn't around anymore...
I'm going to sharpen my axe G> "But to be honest some folks here have been pushing the envelope quite a bit with their unnecessary use if swear words. They just put a character in to replace a letter. But everyone knows what they're saying." Sancho
Ours aren't 6" - of each pair, the upper is around 8-10", the lower goes almost to a point. If you hit that one close to the railing by mistake it is a hazard (from experience). (We have each square which would be a landing normally with one rise across it diagonally.)
I made some winders last year. With 6" at the point and the 10" minimum (I think) 12" from the point, they were very comfortable steps to walk up. I think the reason for the minimum depth is just so there is something to stand on anyplace of the step.
Stairways in dwellings must be a minimum of 36 inches wide. The rise of every residential step shall not exceed 7.75 inches and the tread depth shall not be less than 10 inches. The largest tread width or riser height within any flight of stairs shall not exceed the smallest by more than .375 inch measured at the walk line. Stairways shall have a headroom clearance of 80 inches measured vertically from a line connecting the nosings. Clearance shall extend one tread depth past the bottom riser.
Handrails shall be placed not less than 34 inches nor more than 38 inches above the nosing of the treads. The handgrip portion of handrails shall not be less than 1 1/4 inches nor more than 2 inches in cross- sectional dimension and the handgrip shall be smooth. Ends shall be returned or shall terminate in newel posts or safety terminals. Handrails shall not project more than 4.5 inches on either side of the stairway.
Stairways greater than 30 inches in height must have guards on any open side and all stairways with more than three risers shall have at least one handrail. Open stair railings shall have intermediate rails of an ornamental pattern such that a sphere 4 3/8 inches in diameter cannot pass through.
There shall be a floor or landing at the top and bottom of each stairway. The width and length of the landings shall be not less than the width of the stairway. Interior stairs from the house to the garage need not have a landing provided the door does not swing over the stairs. Doors opening onto a landing shall not reduce the landing to less than one-half the required width. Doors in the fully open position shall not reduce a required dimension by more than 7 inches. There shall not be more than 151 inches vertically between landings.
Oblique stairs - Oblique stairs are stairs where the angle between the line of the front of the tread and the edge of the stair is not 90 degrees. On a curved stair, this angle is measured from a line tangent to the curve at the point where the stair tread intersects the curved edge of the stair. In general, flights of oblique stairs are prohibited. However, widening the bottom of a stair so that the wall and handrail are not 90 degrees to the tread is acceptable provided that the treads vary from each other in a uniform ratio and are otherwise of uniform size and shape. A configuration where the treads meet at an angle in the approximate center of the stair is acceptable, provided the minimum tread width is provided at either side of the meeting point.
Landscape stairs - Landscape stairs are stairs which do not form part of the means of egress, which is the path of exit travel from any occupied point in a building or structure to a public way. Landscape stairs are not required to comply with the requirements of R311.7 the California Residential Code. All other stairs are required to comply with the code.
I found a good source for interpreting the IRC code for stairways at the Stairway Manufacturer's Association website. From here you can download pdf versions of their interpretations of 2000, 2003, and 2006 IRC. If you have ever tried to read the IRC codes you know it is like reading something written by a committee of the US Congress. You can get the pdf version of the 2006 interpretation from this link.
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