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rrekih 05-20-2011 04:12 PM

stairs rise ver: run
 
I have some basement stairs that I am redoing.
The run is 813/4in and the rise is 89in.
If I keep it the same, the stair rise is 8.09in the tread is 8.175in.
Would It be better to have a tread of 9.08in but the rise would then be 8.9in.
I can't change the location or construction of where they are placed.
I know the rise will be higher then what is normal but then the tread would be an easier step.
??????

sixeightten 05-20-2011 04:17 PM

You do not have code stairs either way. What were the previous stairs like?

Tizzer 05-20-2011 04:52 PM

I'm not understanding the question. If the construction(like adding another tread/riser)can't be changed, put back as it was.

DannyT 05-20-2011 05:52 PM

you can keep the same rise and change the run if you make the treads longer.
the last i knew treads needed to be around 10 inches and the rise 7-1/2 - 8 with no more then 1/4 inch difference between them in height. i am assuming this is an older house and those were sufficient back then. usually the stairwell isnt long enough to lengthen the tread without getting to close to the ceiling. it use to be minium 6 foot from tread to ceiling which a lot of older houses dont meet that requirement. open back steps dont have to be 10 inches but if they are closed you need the extra inches so your foot doesnt hit the riser. i see things have changed a bit. the link has updated requirements for stairs. this one is from modesto ca but is probably similar to other states.



http://www.modestogov.com/forms/pdf/...air-detail.pdf


here is the osha stair and handrail regulations

http://www.boomspeed.com/atec/osha/page1.html

rrekih 05-21-2011 01:29 AM

The run is 813/4in and the rise is 89in. This is fixed, this is what I have to work in.
If I keep it the same, the stair rise is 8.09in the tread is 8.175in. This is the existing stairs.
Would It be better to have a tread of 9.08in but the rise would then be 8.9in. To keep it in the fixed run 813/4 and rise 89in.
What I want to know would it be better to have a higher rise with a bigger tread.
Or do I keep it the same with a lower rise 8.09in and rise 8.175in.

Yes it is an old house built in 1932, Vancouver, BC, Canada.

chrisBC 05-21-2011 02:59 AM

Hello from vancouver:thumbsup:

well the rise is the rise, it is the total rise divided by your number of risers. The only way to change this (without changing your stair layout/flooring) is to change your number of risers. Remember you have to keep it to within code.

your run can be whatever you want it to be,within code, providing you have the room for the staircase with a certain run.

what you do when building stairs is follow a stair proportioning rule, to keep your rise/run in proportion. Deeper treads typically should have shorter risers.

I would rebuild your stairs completely to follow code.


common rules:
rise plus run equals 17 to 18 inches

rise times run equals 70 to 75

Millertyme 05-21-2011 08:24 PM

I believe he knows he is out of code either way. He wants to know which is a more comfortable stair. He has no choice but to built the stair in the same amount of space. I would say the bigger run is better, but either way is still uncomfortable. Thats my pick based on my experience

kwikfishron 05-21-2011 08:35 PM

I wouldn’t want a closed riser with things being that tight.

Gary in WA 05-22-2011 12:15 AM

You haven't said headroom... I’m guessing you will hit your head on the sloped ceiling or floor joist above if you add to each run distance; http://publicecodes.citation.com/ico...011_par007.htm


Gary

rrekih 05-22-2011 01:39 AM

Thanks Millertyme
That is what I was asking.
Wider tread over taller rise is more comfortable then shorter tread over shorter rise.
I know that I will be out of code, but I can't change where the stairs are.
There is lots of headroom, but if I add to each run I will run into a wall.

JBaldwin 05-22-2011 03:05 PM

Your question as I understand it is this: "If I change the height of the unit rise while retaining the unit run, will it improve this stair?" The answer is "No".

Since the floor plan space is already determined (and cannot be changed) the original stair "as built" is the best you can do. Any increase of the unit rise will only increase the pitch angle of the stairs.

The original rise/run of 8.09/8.175 = 44.7 degrees, while a rebuilt rise/run of 8.9/8.175 = 47.43 degrees.

rrekih 05-23-2011 12:05 AM

I think I might know where the misunderstanding is.
I will be eliminating one stair (rise) so I can extend the treads.
If I remove one stair then I can extend the other treads by the amount of the one tread I removed.

JBaldwin 05-23-2011 01:20 AM

OK I get it now...10 risers @ 8.9 and 9 treads @9.08 (still) = 44.4 degree pitch. Unless you change the proportion of rise/run you haven't changed a thing. You've increased both the rise and run, but what you need to do is increase one while decreasing the other (it is confusing I'll admit).

The wider step may seem to be the better choice but a unit rise of nearly 9" is unacceptable. The original rise of 8" was the only part of this stair that was close to code compliant.

rrekih 05-23-2011 02:10 AM

That is the problem I can't change the total run distance, so that is why I am considering using 9 treads, I know it will be out of code.
I just want to make it as comfortable as possible with what I have to work with.

JBaldwin 05-23-2011 02:52 AM

At 44 degrees this will never be a "comfortable climb". By eliminating one step, you must now make the same climb in less time. As I've said, 9" is unacceptable as a unit stair rise and not just because of building codes but because of human anatomy (it's a long way to lift your foot).

I believe the carpenter in this old house did the best he could within the allotted space. By altering the original stair plan you also open yourself up to liability as it pertains to the stair. Original "restorations" are usually permitted while changes in stair plans (like plumbing and electrical modifications) require code compliance.


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