I’m trying to get a handle on how state codes vary on stair rise and run. The IRC, if memory serves, is a 7/11 code. However, the Connecticut Supplement to the IRC allows risers of up to 8 1/4 in., and runs as narrow as 9 in.
What does your state allow?
Andy
Never try to teach a pig to sing. It wastes your time and annoys the pig.
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Replies
Used to be based on a "comfort and safety" range. Rule of thumb was Rise X Run= +/- 75. So for a 7.5 rise, run is 10". 7.25=10.5, 7=10.75/11, etc.
That is why on outdoor commercial projects you sometimes see a 5" rise w/ a 15" run. Wierd but still comfortable to walk up/down.
Varies a lot now, but usually in this ballpark.
What does your state allow?
Good question.
I'll have to go look, I'm not sure Texas has a state standard. Only a few of the counties have construction standards, but every incorporated city has some standardized Code. Not one City seems to match another, I know that it runs from 1996 SBC to 2004 IBC just in a few that I've done work in.
Tampa Florida:
For residential dwellings, the Code limits risers to 7 3/4inch maximum and treads must be a minimum of 9 inches in length plus one inch of nosing.
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WWPD
Edited 12/14/2005 12:49 pm ET by Sailfish
Thanks for the replies, gents. Two quick notes to save some effort - I'm mainly interested in residential stairs, and I'm curious what your state is.Andy
Never try to teach a pig to sing. It wastes your time and annoys the pig.
Texas: No State level code that I can find.
Ergo, you have to find the AHJ, and they will tell you. So, my hometown is IRC, the sister town is IBC, except where it's BOCA. Next town west is UBC '99 with amendments; next one south is SBC with amendments.Occupational hazard of my occupation not being around (sorry Bubba)
Michigan. 7 3/4 max riser height 10 min. tread width. this is for straight flight stairs, circular and spiral are different.
colorado (at least gunnison, where i live) is 7 3/4 max riser by 10 min tread. they just adopted this new height, and i got away with some garage stairs that were 7 7/8 recently on my CO....
Thanks for all the info. It is all over the map.Andy
Never try to teach a pig to sing. It wastes your time and annoys the pig.
From Massachusetts State Building code 780CMR
780 CMR 36.03 One and Two Familly Building Planning
780 CMR 3603.13 STAIRWAYS
3603.13.1 Width: Stairways shall not be less than 36 inches (914 mm) in clear width at all points above the permitted handrail height and below the required headroom height. The minimum width at and below the handrail height shall not be less than 32 inches (813 mm) where a handrail is installed on one side and 28 inches (711 mm) where handrails are provided on both sides.
3603.13.2 Treads and risers: The maximum riser height shall be 8 1/4 inches (210 mm) and the minimum tread depth shall be nine inches (229 mm). The riser height shall be measured vertically between leading edges of the adjacent treads. 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 walking surface of treads and landings of a stairway shall be sloped no steeper than one unit vertical in 48 units horizontal (2% slope). The greatest riser height within any flight of stairs shall not exceed the smallest by more than ? inch (9.5 mm) and any two successive risers shall not deviate by more than 3/16 inch in height. The greatest tread depth within any flight of stairs shall not exceed the smallest by more than ? inch (9.5 mm) and any two successive treads shall not deviate in depth by more than 3/ 16-inch.
3603.13.2.1 Nosings: Nosings shall not project more than 11/2 inches beyond the face of the riser below.
etc. etc. etc. yada yada yada
hope that helps
Edited 12/14/2005 1:35 pm ET by xosder11
Hey Andy,NC is using 2002 IRCMax riser hieght is 8 1/4"Spirals can have a 9 1/2" rise. min. headroom 6'6"Top and bottom riser shall not exceed the smallest riser within the run by more than 3/4"(interior stairs).Our winder tread width may not be less than 4" Handrail heights (rake rails): min. 30", max. 38"Can I get a signed copy?<G> Hey, pocket doors can't come off the track if they're nailed open
It'll be about two years...Andy
Never try to teach a pig to sing. It wastes your time and annoys the pig.
The way our code changes, you'll need to bind it with a 3 ringer, and add bi-yearly addendas...job security?<G>You interested in residential exterior stuff yet? I could write a...hey, wait a minuit...ha Hey, pocket doors can't come off the track if they're nailed open
I'll second that comment. Last spring I built a large motel staircase, you would have thought the code would have been etched in stone for commerical however from the time I received the plans to when I finally finished the max riser height changed from 8 to 7 to 7 3/4 in sight of 3 months. I work all over the country and make it a point of having the building code department fax me a copy of the page pertaining to my project. Nothing like a dated received fax to wave at someone should the dodo hit the fan.
Nothing like a dated received fax to wave at someone should the dodo hit the fan.No wonder they're extinct, ha,ha,haaaaa..... Hey, pocket doors can't come off the track if they're nailed open
As a matter of fact, I am interested in residential exterior stairs. Not landscape stairs, but those attached to houses.
Andy
Never try to teach a pig to sing. It wastes your time and annoys the pig.
Exterior stairs: the bottom riser may be less than the height of the adjacent risers. Exterior handrails shall not be more than 3 1/2" in cross-sectional diameter. Interior can't be more than 2 5/8" (so tell me why stair parts suppliers make square edged stuff 2 3/4"?).Exterior storm and screen doors are exempt from requirements for landings. Meaning you don't need the typical 3'x3' landing if there's a storm or screen door, oh well<G> Hey, pocket doors can't come off the track if they're nailed open