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Not a tread or a landing

Big Mac said:
Could be a code compliant winding tread. Depends on the dimensions at the narrow end and at a point 12" in from the narrow end. If the dimension at the narrow end is at least 6" and the dimension at the walkline is consistent with the dimensions of the other treads and risers, it certainly could qualify.
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Hi Big Mac,

R311.7.4.2 ... the largest winder tread depth at the walkline shall not exceed the smallest winder tread by more than 3/8 inch (9.5 mm)... and do not have to be within 3/8"of the rectangular tread depth.

I don't see anything connecting the tread depth of the winders to the regular treads. The risers do have to be withing 3/8" over the whole stairway but not the treads.

Bill
 
Mark Handler's last picture does not appear to meet R311.7.4.2, requirement of 6 inches minimum width at any point within the clear width of the stair.

Compliant? NO.
 
Inspector Gift said:
Mark Handler's last picture does not appear to meet R311.7.4.2, requirement of 6 inches minimum width at any point within the clear width of the stair.Compliant? NO.
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You are correct
 
Maybe the picture is not doing it justice. What you see is a single tread with a depth at walkline of about 18", far greater than the 10" on all the other treads. This would not comply with the uniform tread depth requirement. To equate it with a winder would be to say that a single tread of 18" in a straight run of stairs with 10" treads would be compliant. IMO it half winder, half landing and wholly non-compliant. But, if I am wrong tell me. I don't want to fail anyone if I don't need to.

R311.5.3.2 Tread depth

Within any flight of stairs, the largest winder tread depth at the 12 inch (305

mm) walk line shall not exceed the smallest by more than 3/8

inch (9.5 mm).
 
Would it still be compliant if treads 2 & 3 were combined into one single tread, yet not be large enough to be a landing? That is similar but not as severe as the condition I have.
 
2009 IRC

R311.7.4.2 Tread depth. ... Winder treads shall have a minimum tread depth of 10 inches (254 mm) measured between the vertical planes of the foremost projection of adjacent treads at the intersections with the walk line. Winder treads shall have a minimum tread

depth of 6 inches (152 mm) at any point within the clear width of the stair. Within any flight of stairs, the largest winder tread depth at the walk line shall not exceed the smallest winder tread by more than 3/8 inch (9.5 mm).

Since there is only one winder there is no "smallest winder" to exceed.
 
Rogerpa, don't understand that. By that reasoning the winder riser could be 2 inches high and the rest 7 inches. A winder is part of the entire flight so all the adjacent treads and risers are the ones with which the winder would be compared.....no? A flight is only broken into two distinct and different flights by a landing.
 
2006 IRC commentary:

A stairway may consist of straight

treads, or it may be constructed using winders. If winders

are used, they can either be used for an entire flight of a

stairway, as a portion of a stairway such as at a change

of direction or to form a circular stairway. Winders consist

of tapered treads that are narrow on one end and widen

out, pie-shaped, toward the opposite side of the stairs.

Because they are primarily used to change the direction

of the stair, and they create a change in the rhythm for

the stair user, it is important that winders comply with the

specified dimensional criteria. See Commentary Figure

R311.5.3.2(1) for examples of winders used as a portion

of a stairway at a change of direction.
 
Sifu said:
Rogerpa, don't understand that. By that reasoning the winder riser could be 2 inches high and the rest 7 inches. A winder is part of the entire flight so all the adjacent treads and risers are the ones with which the winder would be compared.....no? A flight is only broken into two distinct and different flights by a landing.
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Sifu,

Tread depths and riser heights are different things.

Tread depths are not to be compared between winders and rectangular treads. Riser heights are a different matter they must all be within 3'8" of each other.

Bill
 
Inspector Gift said:
Mark Handler's last picture does not appear to meet R311.7.4.2, requirement of 6 inches minimum width at any point within the clear width of the stair.Compliant? NO.
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I thought the same thing. Seems like 6", concentric to the walk line needs to be 6" and I don't see it there.

Bill
 
Sifu said:
Maybe the picture is not doing it justice. What you see is a single tread with a depth at walkline of about 18", far greater than the 10" on all the other treads. This would not comply with the uniform tread depth requirement. To equate it with a winder would be to say that a single tread of 18" in a straight run of stairs with 10" treads would be compliant. IMO it half winder, half landing and wholly non-compliant. But, if I am wrong tell me. I don't want to fail anyone if I don't need to. R311.5.3.2 Tread depth

Within any flight of stairs, the largest winder tread depth at the 12 inch (305

mm) walk line shall not exceed the smallest by more than 3/8

inch (9.5 mm).
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Sifu,

Tread depth is measured only against the type of tread, thus winders against winders and standard rect. Treads against rect. Treads.

All the risers are measured against each othe within the flight.

As noted by KZ your case just happens to have only one winder, thus no other tread to compare the depth to.

But, the risers better be within range.

Tom
 
"Tread depths are not to be compared between winders and rectangular treads. Riser heights are a different matter they must all be within 3'8" of each other"

OK, I am seeing a consensus and am starting to be swayed but I would like to know how or where you come by that understanding? If the code requires the same 10" minimum at the walkline as the rectangular treads, and the commentary informs us that winder treads are a portion of a stairway I have trouble inferring that. If it is not a new stairway then the uniformity would need to hold. Like I said, happy to let it go if a valid argument is made but it does not appear to meet the intent as I see it. The tread as it is is too big to take a normal step down on and not big enough to take a normal horizontal stride. It requires shuffling your feet or one giant step for mankind. Would you think that is the intent of the code?
 
Big apology to ALL. Don't know why I didn't check this first. The 2009 interpretations book has this very issue word for word. You are all correct, I am not. "...not required to be the same depth as straight treads within the same flight...."

I will look at the other requirements as mentioned but those I think will be easy to rectify. Sometimes it feels OK to be wrong!
 
I Just like to See an Inspector try measuring those to see if they met code or not! If the rise is correct which we can't tell from the pictures measuring the run would present a major challenge.

I'm also not so sure they tried very hard!
 
I Just like to See an Inspector try measuring those to see if they met code or not! If the rise is correct which we can't tell from the pictures measuring the run would present a major challenge.I'm also not so sure they tried very hard!
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The rise is consistent all the way up, treads...not so much.

I was getting a headache trying to explain how that's not what was on the approved plan, and why no, I will not approve them as-is.
 
When we get weird ones like this, the framer will usually sketch them out on the floor before they build them. We come and check the the sketch and sign off before they start building them. Later we come back and check the rise.
 
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