Replies

1. 
   4Lorn1 | Aug 24, 2002 04:50am | #1

   Not being a carpenter I'm not an expert on stairs but my understanding is that the dimensions of treads and risers are pretty tightly defined in the building codes. Check with the AHJ. Also I have heard that anyone who happens to get hurt on a noncompliant stair may have a basis to sue.

1. 
   UncleDunc | Aug 24, 2002 05:58am | #2

   Ditto what 4LORN1 said. Plus, a stair that seems perfectly comfortable now may not be in the future. I'm diabetic and my brother-in-law has MS, and the basement stairs at both our houses are steeper than we'd like. And even folks who stay healthy eventually get old.

2. 
   Qtrmeg | Aug 24, 2002 06:27am | #3

   One of the stupit rules of thumb is the rise and run should total 17".

   Codes will give you a maximum rise, and a minimum run. Depends where you are.

1. 
   Edgar76b | Aug 24, 2002 06:40am | #5

   7" is the code around here with a 10" tread and an 1/1/4" nose. The lower the rise the longer the run should be to keep things psycologically compliant as well. 6"rise would be 11" run , 5" /12" etc. People travel stairs instictually . Just like breathing, we have learned to expect that next step, to be where it is supposed to be. Not only that, if you are building the stringers yourself you don't want to go any deeper into your 2 x 12. It will weaken it . 

   That 3/8th difference is news to me . Interesting. I always get my calculator out and take it to a 1/16"

   "I was born in the country, razed in the city, I'm a natural born shaker from my hips to the ground" 

   Edited 8/23/2002 11:51:55 PM ET by Edgar76b

3. 
   JerraldHayes | Aug 24, 2002 06:36am | #4

   FUPCREEK- you might want to checkout this document. It's the Visual

   Interpretation Of The International Residential Code-2000 Stair Building Code

   I think it has what you are looking for on about the third page.

   ---

   

   "Architecture is the

   handwriting of Man." - Bernard

   Maybeck.

1. 
   Edgar76b | Aug 24, 2002 06:46am | #6

   You the man ! Jerrald. I have gotton more good links from you. Has there been any news about the adoption of the International code nationwide?  That 3/8th difference is news to me . Interesting. I always get my calculator out and take it to a 1/16"

   "I was born in the country, razed in the city, I'm a natural born shaker from my hips to the ground" 

   Edited 8/23/2002 11:54:16 PM ET by Edgar76b

1. 
   JerraldHayes | Aug 24, 2002 07:07am | #7

   Edgar I'm actually embarrassed to say I don't know where we are in regard to the adoption and recommended changes to the codes. I guess it’s just another thing I have to put on my list to think about. I did read something about what some of the change recommendations were but I can’t recall where I read them or what they were tonight. When you mentioned 3/8" were you referring to the maximum difference between tread or nosing projection? I can never remember all this stuff so than got for PDFs like this one.

   "Architecture is the

   handwriting of Man." - Bernard

   Maybeck.

1. 
   MisterT | Aug 24, 2002 02:51pm | #8

   The 3/8" refers to the max difference in the rises of steps.

   Mostly for Hacks that don't understand what dropping a carriage is or why it should be done.

   So you dont end up with the top and bottom rises being 1" bigger or smaller than the rest.

   Good way to trip up someone. give them a constant pitch and them just as they reach the end the last step is not where they think it is.

   My 2$

   Mr TDo not try this at home!

   I am a trained professional!

1. 
   JerraldHayes | Aug 24, 2002 04:20pm | #9

   Mr T the reason I was asking Edgar about which 3/8" he was referring to is that there is also a maximum of 3/8" that the overhangs of the nosing can vary. I not at all sure why that 3/8" would matter safety-wise and therefore be part of the IRC code but it is there nonetheless. The 3/8" as it applies to riser differentiation makes tons of sense to me however and I seen it apply in real world mistakes and problems too that needed correction. Nine times out of ten they were homeowner built stairs. Your "Do not try this at home! I am a trained professional!" tag line would certainly seem to apply to stair and railing work if nothing else.

   "Architecture is the

   handwriting of Man." - Bernard

   Maybeck.

2. 
   Snort | Aug 24, 2002 05:53pm | #10

   Good link. We (NC) are currently governed by CABO and city/county addendas, but I think we're going to the International Code next year...some big differences in stairs:

   cabo max rise is 8 1/4" and top and bottom rises can be up to 3/4" different

   tread width 9"

   1" max tread overhang

   min. width on winders is 4"

   handrails (up the stairs) have a min height of 30" . The last time this was bumped up to 34", the railing parts manufacturers never changed their newel or baluster heights, made for a fun time installing...

3. 
   Edgar76b | Aug 27, 2002 02:59pm | #15

   Jearld how's it going ?

   Hey do you know if that 3/8 tolerence is a carryover from old codes? I have never seen it spelled out that way in my research. I can see how that will make it easier."I was born in the country, razed in the city, I'm a natural born shaker from my hips to the ground" 

4. 
   xMikeSmith | Aug 27, 2002 11:52pm | #16

   yes, the 3/8 has been a part of the stair code as long as i remember ('75).. it is just there to give the inspector something to hang his hat on.. if the stair builder is sloppy (never mind the math). he can get a cumulative error. or just cut the horses wrong...for some reason. it was determined that 3/8 could be tolerated as a difference from the least riser to the greatest riser...

   this certainly throws out the one who forgot to shorten the first step by the thickness of the tread or didn't allow for finish floor heightMike Smith   Rhode Island : Design / Build / Repair / Restore

5. 
   Edgar76b | Aug 28, 2002 12:33am | #18

   yeah I guess They need that kinda leverage sometimes. The thing that bugs me, are the stringers, Which they pre-cut for decks, at the homebuilding centers. People are instructed to cut the bottom, to arrive at the finished deck level. That is just bad all the way around. Who is responsible if someone gets hurt on that deck. I guess the Homeowners insurance. By easing that transition for the customer. The supplier under mines us all. Obviously the average DIY won't be able to finish the deck if he can't cut a stringer. But he also gets an Inferior addition to his Property. Insurance companies pay when someone gets hurt, wasting wood which will probably not last. All Becasuse of poor quality workmanship. "Any job worth doing is worth doing right."  Lately one of the home cnters is offering deck design. All of the plans are based on a free standing deck, bolted to 4 x 4 's on pier blocks above the ground. the building code equivalent of a Picnic table. No footers, no permits, no digging,or getting permission to dig. Its all about waking up on saturday morning,  I think i'll buy a $800 worth of lumber today and build a deck.

   Although I might end up getting some work out of it all. It just goes against my efficient minded approach to doing things right.

   Thanks for the chance to vent .......again"I was born in the country, razed in the city, I'm a natural born shaker from my hips to the ground" 

6. 
   xMikeSmith | Aug 28, 2002 12:57am | #19

   edgar. you didn't bother to read the instructions that come with the pre-cut stringers:

   shorten 1st riser by thickness of tread ,then adjust ht of deck so it is an even number of risers above ground  OR..... adjust ground so it is an even number of risers below deck...

   hah, hah, hahMike Smith   Rhode Island : Design / Build / Repair / Restore

7. 
   Snort | Aug 28, 2002 02:06am | #20

   I don't get that comment about sloppy stairbuilding being the the reason for a 3/8" variance...CABO: "the top and bottom riser of interior stairs shall not exceed the smallest riser within that stair run by more than 3/4." Hey, that's just between landings, too. Does this code accomodate sloppy stairbuilding/ poor planning or what? I've always been a fan of below 7 1/2" rises and keeping them all the same, but in doing finished stairs, I have been tested to get the 3/8" difference in rise between the runs, along with the top and bottom 3/4" thing...no matter how close to the edge this has ended up, the stairs have still felt safe...I do think there is a limit, but even though this one accepts incompetance, I don't think it pushes safety over the edge...yet.

8. 
   Edgar76b | Aug 28, 2002 06:11pm | #21

   yeah I do that sometimes I forget the directions. I still say it would be easier to take a course of block out of the foundation. And Lower the House lol."I was born in the country, razed in the city, I'm a natural born shaker from my hips to the ground" 

9. 
   JerraldHayes | Aug 28, 2002 12:16am | #17

   Hey Edgar I'm a little busier than I want to be right now but that's an whole

   other story I guess. Scheduling delays and other glitches have me all piled

   up for three weeks now although I can see the light at the end of the tunnel

   coming possibly as early as tomorrow but certainly no later than this weekend.

   One of the problems with some of the stairwork we do is the the custom parts

   we make for stair railings. The problem is I'm the only one who makes the helical

   and free-form parts and because of various delays on three different projects

   all three of them got piled up on top of each other for this August so I've

   been a little over extended as a resource lately.

   I will defer to Mike regarding the 3/8" rule being around since '75 and

   accept his word as gospel. I was fresh out of high school then and having just

   discovered drinking that was a period in my life where I don't remember much

   of anything. My experience with stairs back then was with doing stunt prat falls

   down them at parties which it turns out I was very very good at.

   I know the 3/8" differential allowance has been around at least since

   1990 since it is in a 1990 BOCA book I have here at home.

   "817.6.1 Dimensional uniformity: There shall not be variation

   exceeding 3/16 inch (5mm) in the depth of adjacent treads or in the height

   of adjacent risers. The tolerance between the largest and smallest riser or

   between the largest and smallest tread shall not exceed 3/8 inch (10mm) in

   any flight of stairs"

   I can't recite what it says in the current codes since those books are down

   in the shop. Like I think I've said before I can never remember all this stuff

   so I constantly print out notes whenever I'm working hands-on on an actual project

   so I have something at hand to refer to.

   Regarding your comment "when i did my first staircase

   I didn't have the advantage of helping some one else do one." Neither

   did I. My first staircase (an L-shaped staircase with a diagonal skewed balcony

   rail) was I think back in the summer 1987 and the only thing I had to go on

   was a Fine Homebuilding article on installing handrailings. I probably just

   luckily stumbled on the right method for figuring and planning the stair part

   of the project. Everything I have learned since then has been self taught or

   discovered too. I was figuring out and doing helical railing work two or three

   years before I ever discovered there was a book on the subject (A

   Simplified Guide to Custom Stairbuilding and Tangent Handrailing). My background

   as a sculptor I think may have helped me there.

   Given all the information that is out there nowadays and the help and advice

   that you can get via web sites like this one JLC, and Woodweb I'm not so sure

   I would recommend my niave-didn't-know-I-was-way-over-my-head approach to anyone

   else today. There are certainly faster and safer way to learn now although I

   will admit that I'm pretty proud I figured out what I did when I did. I'm a

   lot more comfortable and secure pioneering new and different techniques to day

   although we still have our challenging moments like tomorrow when I have to

   make a free formed helical easing to get the maximum amount of drop in a railing

   so a landing newel can be shortened to an artistically decent looking height

   "Architecture is the

   handwriting of Man." - Bernard

   Maybeck.

10. 
    Edgar76b | Aug 27, 2002 02:57pm | #14

    Jerrald I was refering to the 3/8 as a magic number. That seems to be the tolerance that the new code allows for making thes things work. personally I have always taken it one step farther. I will adjust my rise and run when possibel to make it the same all the way up. It all works out if you have the decimal equivelents of the fractions, you are working with. It just takes a little time. But when i did my first staircase I didn't have the advantage of helping some one else do one. so if the 3/8 was a standard, before too, I wouldn't know. I guess i will start measuring all the staircases I see. To see how everyone else has done it. "I was born in the country, razed in the city, I'm a natural born shaker from my hips to the ground" 

4. 
   exlrrp | Aug 25, 2002 06:10am | #11

   the UBC provides an exception to the 7'rise/11"run if the occupancy load is less than 10--this is virtually all single family residences.

   the exception allows 8" rise and 9" run

   Ive built a lot of stairs at this dimension and no one ever complained about it--they'd rather save the space.

5. 
   RoyW | Aug 25, 2002 06:33am | #12

   I don’t think a 10” inch tread depth that includes a 2” backcut is considered a 10” tread. You can walk up a set of stairs with a backcut or overhang because you can jam your toe into the riser , but you can’t walk DOWN them well- Most serious accidents happen walking downstairs. Check on the plumb measurement if you are pushing the code.

1. 
   BossHog | Aug 25, 2002 02:54pm | #13

   Ditto what the "Dude" said - Going up might be fine, but going down won't. This is a foolish thing to do, IMHO.

   When I die, I'm leaving my body to science fiction.