Tread/Riser Dimension Amendments

[brudgers]

So instead of lobbying the ICC, the special interest group(s) figure they can pick off States one at a time because they have more political leverage on the state level.

There's a bit more to it than that. Changes in stair dimensions have a huge effect on the homebuilding industry in a way that most other code changes do not because changes to the stair requirements radically affect floor plans, particularly as houses get smaller and space becomes more critical...I lived through proposed stair changes during the FBC 2004 cycle while at Pulte during the boom...the FBC was going to follow NFPA 101 with 7/11 for dwellings, until order was restored by the legislature in the waining days of the session and NFPA 101 Florida edition was modified to match the building code.

 

[NH09]

I was sent a link to a report "A Review of the Literature and Data Concerning Stair Geometry and Other Characteristics". I've only begun to read the document, but it appears there is a lot of information in it. Thanks for the other link High Desert, I'll take a look at that one as well. Here's a link the the review if anyone is interested:

http://www.toolbase.org/Best-Practices/Codes-Regulations-Standards/stair-safety

 

[Yankee]

There's a bit more to it than that. Changes in stair dimensions have a huge effect on the homebuilding industry in a way that most other code changes do not because changes to the stair requirements radically affect floor plans, particularly as houses get smaller and space becomes more critical...I lived through proposed stair changes during the FBC 2004 cycle while at Pulte during the boom...the FBC was going to follow NFPA 101 with 7/11 for dwellings, until order was restored by the legislature in the waining days of the session and NFPA 101 Florida edition was modified to match the building code.

I am well aware of the impact of the stair design on the floor plans and the argument that the proposed numbers would aid the building industry to build less expensive houses. But the line should be somewhere and if the line in the IRC isn't a good enough compromise, then that is where the change should take place not on a state by state basis. This code item is not intertwined with regional climates etc etc where an amendment might be warranted. Unless for some reason 90% of the population of a state has smaller than average feet . . . uhhh, , let's not go there . . .

 

[georgia plans exam]

Georgia amendments to R311 kept the 7 3/4" riser height but allows a 3/4" variation at the first and last riser and allows a 9" tread depth.

GPE

 

[tbz]

The 8-1/4" by 9" tread is amended in more places than not, as for the 7-3/4" x 10" it was a compromise from just adopting the 7" x 11" from what I can remember. However, I could be wrong.

The main key though is no change in the geometry, the 3/4" change allowed in the GA adoption I would say is a bigger problem then the 8-1/4" vrs the 7-3/4".

We all have come down those set of stairs that has a small riser at the bottom and almost trip in gait.

The same is true when the top riser is higher than the flights standard you tend not to pick the foot up enough and trip.

NJ amended it in the IRC to 8-1/4" x 9" when adopted.

 

[TimNY]

Well, the analyzing seems to be focusing on who is driving the change in the states.. I am curious as to who determined the requirements in the unabridged code? I just don't see an issue with the 8-1/4"x9".. I have that in my own house.

Interesting story one of our NYS code instructors told us about our building code prior to using the i-codes.. "you know why the ceiling height was 7'-6"? Well, I asked one of the guys who wrote the code.. he said they were all in the office one day and had to decide on a ceiling height. One guy said 7'-6" sounds good"

 

[brudgers]

I am well aware of the impact of the stair design on the floor plans and the argument that the proposed numbers would aid the building industry to build less expensive houses. But the line should be somewhere and if the line in the IRC isn't a good enough compromise, then that is where the change should take place not on a state by state basis. This code item is not intertwined with regional climates etc etc where an amendment might be warranted. Unless for some reason 90% of the population of a state has smaller than average feet . . . uhhh, , let's not go there . . .

Local governments should make local decisions and state governments should make state decisions. We don't need a national building code, and in any event the dictates of the ICC should not take precedence over state governments. Supreme executive authority derives from a mandate from the people not some farcical aquatic ceremony.

 

[peach]

almost every jurisdiction amends it; the IRC requirement adds a requirement of about 56 extra square feet per floor (it doesn't work in narrower, shallower houses).

MHO: people who live in a house are going to be familiar with the stairs; it's the turnout gear that fire fighters wear that make the steeper stairs harder to manipulate.

In Single family homes, the fire fighters generally aren't going to have to deal with more than 3 flights of stairs (or the house is probably an IBC building).

 

[peach]

almost every jurisdiction amends it; the IRC requirement adds a requirement of about 56 extra square feet per floor (it doesn't work in narrower, shallower houses).

MHO: people who live in a house are going to be familiar with the stairs; it's the turnout gear that fire fighters wear that make the steeper stairs harder to manipulate.

In Single family homes, the fire fighters generally aren't going to have to deal with more than 3 flights of stairs (or the house is probably an IBC building).

 

[brudgers]

MHO: people who live in a house are going to be familiar with the stairs; it's the turnout gear that fire fighters wear that make the steeper stairs harder to manipulate.

I doubt residential stair present a challenge, given EE&RO requirements.

 

[Yankee]

Local governments should make local decisions and state governments should make state decisions. We don't need a national building code, and in any event the dictates of the ICC should not take precedence over state governments. Supreme executive authority derives from a mandate from the people not some farcical aquatic ceremony.

I think NH09's question was should his state amend the code, , , the decision NOT to amend the ICC code is then still A State Decision and is still a mandate from the people of that State. As for me, if there isn't some driving local reason to change something in the adopted ICC code, then it should not be changed. If a state wants to write their own code book then that is what they should do.

 

[Yankee]

almost every jurisdiction amends it; the IRC requirement adds a requirement of about 56 extra square feet per floor (it doesn't work in narrower, shallower houses).

I don't believe that number is correct. Assuming 99" fl to fl, the 10/7.75 is a 10' run and the 9/8.25 is a 8'3" run. that is 1'-9" longer time 3' for the width, that is less than 6sf. , , ah, you must have had a typo and hit the "5" also.Alrighty then, I will compromise and say that IF the house is going to be 24' wide, then they are allowed the 9/8.25. But if they "want" a wider house or a house with taller ceilings, they must meet the 10/7.75.

That's fair, right?

 

[TimNY]

I never went into a burning residence and said, "man, these stairs suck". "It's F$&*$& HOT IN HERE!" maybe.. but I wouldn't even bring the fire service into this discussion on a residence.. I just don't think there is anything to back it up.

Do enough studies and you can bend the data any way you want. In reality I never heard a peep about the tread depth when a building was on fire.

How about the ICC take a hint from the people adopting their codes and just change it.

 

[Architect1281]

Job Saver - Not so Slippery in RI -

in order to keep the stairs from being slippery provide the following ammendment to the IRC 2009

R313.1 Delete R313.1 and 313.2 and substitute the following

R 313.1 General.

Automatic fire sprinkler if installed at the applicants option will be in conformance with Appendix R

 

[Daddy-0-]

As Paul S. said, we (Virginia) amended the stair section. Virginia changes a lot of the codes through an amendment and appeals process and then the ICC actually publishes a "Virginia" code which is the IRC, IBC, IPC etc. with the Virginia changes in it.

We have a lot of colonial style houses here which are typically not very deep. The stairs in those houses often do not hit a landing and turn. The amended stair rise/run helps fit this style of stairs into the most popular Virginia house designs.

 

[Yankee]

I understand the design issue. I wonder though, how many new houses, even lower end houses, are less than 28' wide based on other wants? Since I don't have many if any in my area, I'd like to know what the other experiences are? In general, a "style" can be maintained with a small change in "scale" (ie from 24' to 28'), if a design pro is involved even to a small extent.

 

[TimNY]

Has there actually been data to support a 10" tread is safer than a 9" tread, or is it just a matter of "it's bigger, so it HAS to be better"

If we eliminated stairs altogether and just used a series of landings, I bet it would be even safer yet!

I just don't see the need. I am speaking in regard to the residential code; in the commercial code I can understand it based on increased occupancy, unfamiliarity with the stairs etc.

 

[Yankee]

How about the ICC take a hint from the people adopting their codes and just change it.

Doesn't someone not on ICC staff need to bring it forth?It's a number chosen as a compromise between two other numbers. There's a reason we don't allow ladders but I doubt there is an exact number that is "safer" than another similar number.

It sounds like most on this board would be in favor of changing the number based on . . . . not sure what, but there you have it.