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Stairway was this code?

Stairway was this code?

New postby David on Thu May 07, 2009 12:53 pm

Hi Jerry,
In this Atlanta home built in 1986, the stairway has tread depths of 11 1/2" & risers of 7 3/4" and the nose on each tread is 3 1/2" - 3 3/4". Was this code at the time? What do I advise my client and the agent? They are concerned about resale.
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Joined: Thu May 07, 2009 12:32 pm

Re: Stairway was this code?

New postby Jerry Peck - Codeman on Thu May 07, 2009 2:31 pm

Hi David,

David wrote:In this Atlanta home built in 1986, the stairway has tread depths of 11 1/2" & risers of 7 3/4" and the nose on each tread is 3 1/2" - 3 3/4". Was this code at the time?

What you are describing where one tread (imagine an open riser stair for right now) overhangs the tread below by 3-5/8 inches (using the average of your 3-1/2 inches to 3-3/4 inches). That means that standing on a tread now puts your foot under the tread above by that far. Now, because you were able to measure that overhanging tread depth, that means there was a riser set back that 3-5/8 inches from the front of the nosing on the tread above, making the nosing, not the thread, 3-5/8 inches deep.

If you measured 11-1/2 inches for the tread depth, physical measurement, that means the actual "tread depth" is the physical measurement less the nosing, in this case that would be 11-1/2 inches less 3-5/8 inches of nosing for a "tread depth" of 7-7/8 inches.

No, the tread depth has never been allowed to only be 7-7/8 inches. The minimum nosing, exclusive of nosing has been 9 inches going back a long way back in time, long before that house was built.

Additionally, even back then, every tread depth which was less than 10 inches was required to have a 1 inch nosing, thus the minimum "foot print area" for your foot would have been 9 inches plus a 1 inch nosing, or 10 inches less the profile radius, bevel, along the front of the nosing - but consider the minimum "foot print area" to be 10 inches in depth.

Also, the maximum nosing allowed has been "approximately 1 inch" and 3-5/8 inches IS NOT "approximately 1 inch". The "1 inch" was the design measurement, the "approximately" as to allow for construction tolerances, say maximum of 3/16 inch construction tolerance on something like that, leaving "approximately 1 inch" as meaning 13/16 inch to 1-3/16 inch, which would allow for the same 3/8 inch variance allowed for treads and risers.

The following is from the 1994 Standard Building Code, which was not much, if any different going back long before then - stair construction has been fairly consistent in their requirements over the decades, with the exception of the openings allowed in guard rails, which have been made smaller over the decades.

You will see the 3/16 inch limitation and the approximately 1 inch nosing limitation in the code below. (underlining and bold are mine)
- - B1007.3.1 Treads and risers of stairs shall be so proportioned that the sum of two risers and a tread, exclusive of projection of nosing, is not less than 24 inches (610 mm) nor more than 25 inches (635 mm). The height of the riser shall not exceed 7 3/4 inches (197 mm), and treads, exclusive of nosing, shall be not less than 9 inches (229 mm) wide.
- - - EXCEPTION: Special stairs in B1007.8.
- - B1007.3.2 Every tread less than 10 inches (254 mm) wide shall have a nosing, or effective projection, of approximately 1 inch (25.4 mm) over the level immediately below that tread.
- - B1007.3.3 Tread depth shall be measured horizontally between the vertical planes of the foremost projection of adjacent treads and at a right angle to the tread's leading edge.
- - - EXCEPTION: Tread depth of special stairs in B1007.8 shall be measured on a line perpendicular to the centerline of tread.
- - B1007.3.4 Treads shall be of uniform depth and risers of uniform height in any stairway between two floors. There shall be no variation exceeding 3/16 inch (4.8 mm) in the depth of adjacent treads or in the height of adjacent risers and the tolerance between the largest and smallest riser or between the largest and smallest tread shall not exceed 3/8 inch (9.5 mm) in any flight. The uniformity of winders and other tapered treads, complying with B1007.8.1, B1007.8.2, and B1007.8.3 shall be measured at consistent distances from the narrower end of the treads.
- - - EXCEPTION: Where the bottom or top riser adjoins a sloping public way, walk or driveway having an established grade and serving as a landing, a variation in height of the riser of not more than 3 inches (76 mm) for every 3 ft (914 mm) of stairway width is permitted.

The following is from the 2006 IRC. (underlining and bold are mine)
- R311.5.3 Stair treads and risers.
- - R311.5.3.1 Riser height. The maximum riser height shall be 7 3/4 inches (196 mm). The riser shall be measured vertically between leading edges of the adjacent treads. The greatest riser height within any flight of stairs shall not exceed the smallest by more than 3/8 inch (9.5 mm).
- - R311.5.3.2 Tread depth. The minimum tread depth shall be 10 inches (254 mm). The tread depth shall be measured horizontally between the vertical planes of the foremost projection of adjacent treads and at a right angle to the tread’s leading edge. The greatest tread depth within any flight of stairs shall not exceed the smallest by more than 3/8 inch (9.5 mm). Winder treads shall have a minimum tread depth of 10 inches (254 mm) measured as above at a point 12 inches (305 mm) from the side where the treads are narrower. Winder treads shall have a minimum tread depth of 6 inches (152 mm) at any point. 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).
- - R311.5.3.3 Profile. The radius of curvature at the leading edge of the tread shall be no greater than 9/16 inch (14 mm). A nosing not less than 3/4 inch (19 mm) but not more than 11/4 inch (32 mm) shall be provided on stairways with solid risers. The greatest nosing projection shall not exceed the smallest nosing projection by more than 3/8 inch (9.5 mm) between two stories, including the nosing at the level of floors and landings. Beveling of nosing shall not exceed 1/2 inch (12.7 mm). Risers shall be vertical or sloped from the underside of the leading edge of the tread above at an angle not more than 30 degrees (0.51 rad) from the vertical. Open risers are permitted, provided that the opening between treads does not permit the passage of a 4-inch diameter (102 mm) sphere.
- - - Exceptions:
- - - - 1. A nosing is not required where the tread depth is a minimum of 11 inches (279 mm).
- - - - 2. The opening between adjacent treads is not limited on stairs with a total rise of 30 inches (762 mm) or less.

What do I advise my client and the agent? They are concerned about resale.

How to address this?

There are always 3 options:

1) The worst option: Ignore it. Like it or not that is an option, albeit one I never recommend my clients take. "ignoring it" can have dire financial consequences at some future date, not to mention some trip and fall injuries or death. While "ignoring it" *IS* an option, it really is not an option one wants to accept lightly.

2) The best option: Fix it. This is the best option as the problem is now corrected and no longer exists. However, as with many construction issues, there are other parts of the structure which need to be considered when fixing/correcting something, one is "is it even feasible or practical" to "fix it"? In some cases, the answer is " *Yes, it can be fixed*, but *no, it is not practical or feasible to fix it*. In the case of this stairway, as we discussed on the phone, there is no "practical and feasible" way to correct it/ fix it - not without major work on redesigning the structure and moving walls around.

3) The most common option: Take money for it. This is the most common option as the buyer "accepts the condition for $xxxx" and then becomes liable for the correction of that item themselves, should they so chose to do so - which they should, but no one can make them correct it. Taking money for it really has to secondary aspects to it, which can be taken singly or added together and taken together:
- 3) a) Take money to correct it. This involves, at times, major amounts of money, or at some agreed upon portion of sharing between the seller and the buyer. Either way, the money taken is for "corrective action".
- 3) b) Take money to protect against liability associated with the problem. This involves, in the example of the stairway in question, taking an amount equal to what the buyers homeowners insurance will charge, may charge, to specifically address the issue with a policy rider. This amount may be, an example I frequently use, $100 per year, and with a 30 year mortgage as typical, that would mean $100 x 30 = $3,000. One could also calculate that on the life of the house less its age, in this example that would be 75 years (FEMA based life of a house) less 23 old, or 75 - 23 = 52 years remaining, that would mean $100 x 52 - $5,200. Also consider that it may cost more than $100 per year to insure for something which is known that will happen, i.e., with a stairway like that, someone *WILL* fall, *WHEN* is the only part which is unknown, thus the insurance rider may cost more than the $100 per year used in my example.

Now, option 2) Fix it, can be done by either the seller spending money to "fix it" or giving money to the buyer to "fix it", and, if the buyer does not "fix it", then the buyer should be advised that they will simply pass that money on to their buyer when they become the seller.

Most often, option 3) is chosen, "Take money for it.", and sometimes it is a combination of 3) a) AND 3) b), i.e., "Take MORE money for it."
Jerry Peck - CodeMan
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