Stair riser height and tread calculation

[patrick]

I change the title of the thread : "question for everyone" to "Stair riser height and tread calculation" so it can be indexed.

If you post a question, please keep this in mind.

The following thread posted by Matt show how to calculate stair riser height and tread versus floor height to meet code.

http://www.chieftalk.com/showthread.php?t=16592

Thanks

[mldecker68]

Keep in mind that the code min/max results in a stairway that is too steep for comfort. Francis D.K. Ching includes a wonderful cheat sheet in his book "Building Construction Illustrated" which offers the following rules of thumb for building comfortable stairs:

Angle between 30-35 degrees
riser X run = 72 to 75 inches
riser + run = 17 to 17.5 inches
2(riser) + run = 24 to 25

I find the angle one easy to use with Chief because the program automatically calculates and displays the stair angle in the stair dbx. Also, the angle rule limits you to those stair configurations that are actually easy to climb. Stairs that are too steep are tiring, and stairs that are too shallow make you trip. Myself, I aim for a riser just over 7", and a tread of 11.5", then tweak it to meet the FTF distance.

Hope this is helpful,

Mark

[mldecker68]

Keep in mind that the code min/max results in a stairway that is too steep for comfort. Francis D.K. Ching includes a wonderful cheat sheet in his book "Building Construction Illustrated" which offers the following rules of thumb for building comfortable stairs:

Angle between 30-35 degrees
riser X run = 72 to 75 inches
riser + run = 17 to 17.5 inches
2(riser) + run = 24 to 25

I find the angle one easy to use with Chief because the program automatically calculates and displays the stair angle in the stair dbx. Also, the angle rule limits you to those stair configurations that are actually easy to climb. Stairs that are too steep are tiring, and stairs that are too shallow make you trip. Myself, I aim for a riser just over 7", and a tread of 11.5", then tweak it to meet the FTF distance.

Hope this is helpful,

Mark

[hdewerth]

Stairs are a thesis in themselves. As a contractor & designer the best advice is to keep with the simple 7/11 rule. Try to keep risers close to 7" (less is better) and the treads or runs at 11" (this does not count the bullnose which will make it 12" in most cases. In commercial work the risers will be 6". The carpenter rule of 2 risers plus 1 run(tread) should be between 24" & 25" with the max risers at 7 3/4" --- Bottom line is if you don't want people to fall use the 7/11 min rule - on the 11' (132") you would shoot for 19 risers. Most codes allow any differences either a slightly shorter or taller riser to be used at the bottom or top of the stair.
You can generally climb the stiars okay if the risers and threads are at the max/min permissable by code but because the bullnose helps -- coming down you don't have the extra inch and you tend to move your center of gravity forward - boom fall down the stairs. You might end up with a very unhappy home owner after the fact - even though it meets code.
One other note: make sure your stiarways are at least 36" wide - 42" is best. I've seen stairs to narrow (particularly winders) where people could not get funiture to the second floor. Stair desig is a real art - the tools in chief work pretty well, just deal with reality. You don't want any liabilty later on if someone falls.

[ebdesign]

I just divide the total rise (floor-to-floor) by 7.5" (my personal max riser hgt), & then round up to the next whole number. For instance, 121 1/8" (9'ceiling & 12" 2nd floor depth)/7.5" = 16.15 risers rounded up to 17. 17 risers @ 7 1/8" & 16 treads @ 10" needs 160" run total. The actual tread width is 11"+ w/ the nosing.
That is a comfortable stairway, even for these old bones.
Jim

[PhoenixConstruction]

After 35 years and hundreds of staircases (designed AND built), the best that we've come up with for an ideal "running" staircase (you can run up and down without tripping and killing yourself), irregardless of the code or rules of thumb, is exactly an 11" tread and no more than a 7 1/4" rise. The tread depth includes the 1" nose with a 5/8" round-over top and bottom. If the riser is angled back, don't exceed the 1" dimension from vertical, and do eliminate the tread extension, but keep the 5/8" round-over on the top. There is no such thing as making the stairs to fit the structural consideration, for safety and comfort, it's more important to make the structural or layout to accomodate the stair case. For elderly folks and children, both of which are more prone to stair accidents, these are extremely comfortable dimensions. If a secondary access is being created, and the primary access meets these criteria, then the rules can be bent if necessary.
Class over .

[louis]

I shoot for a 7/11 ratio.

[kernsdan]

FYI. I did an addition for a couple in their 70's with a basement for storage. They insisted on making the stair run as short as possible. I argued for their sake but they wouldn't budge. Code, then allowed 8" rise and 9" run. We did it and I was amazed how comfortable they worked out. Changed my thinking!

[shir]

I change the title of the thread : "question for everyone" to "Stair riser height and tread calculation" so it can be indexed.

Patrick ,
How can you change the title of the thread , because I want fix rong spelling in one I sent it.

[lbuttery]

Shir:

He started a new thread with the new title.

Existing posts can be edited by the poster but the thread title can't be changed (as far as I know ?)

Lew

[shir]

I see
thanks for your replied Lew,

Other Question , how did you upload this beautiful logo for castle ?

[Allen42acj]

Shir
Go to your profile=user CP=edit Avatar
Same as uploading a picture.
If you want Lew's castle,right click on the image and save but that would be like using his name.. Maybe if everyone used it
The Lew fan club.
Sunday morning=I can be silly