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i think 16 but im not so sure

Actually no. It's not a set standard, but it typically works out to between 12 and 14. There are 4 critical dimensions in stair construction - regardless of the dimension from floor to ceiling - and which determine the number of 'steps'.

The RBCUS (Residential Building Code for The United States) and the UCB (Universal Building Code) present the most universally accepted standards for stair construction. There are four critical dimensions, or ranges of dimensions, in stairway construction. They are;

1.) The generally accepted stair 'WIDTH' is a minimum of 36" - providing that any

handrail does not extend more than 3" into the 36" TREAD WIDTH.

2.) The generally accepted 'TREAD DEPTH' (each step) is 9" to 10" measured from

the nose of the TREAD (step) to the nose of the next TREAD (step above).

3.) The generally accepted RISE or RISER HEIGHT (top of one TREAD (step) to the top of the next TREAD (step) must be no less than 7-3/4" nor more than 8-1/4".

4.) Although not common on carpeted stair runs, there is also a NOSE EXTENSION

dimension which is critical on each stair tread. This dimension is how much the stair TREAD NOSE (step) overhangs the RISER below at the front of the TREAD. Typically this dimension must be no less than 1-1/4" and no more than 1-1/2". Of course, if the TREAD DEPTH meets the maximum of 10", then a TREAD NOSE (or overhang) is not necessarily a big concern.

Thus, a typical ceiling height of 8' (96") would require 14 RISERS and 13 TREADS.

Which means, although there are only 13 TREADS, one must take 14 steps from 'floor' to 'floor'. Although the ceiling height may be 8' (96") one must also take into consideration, as one ascends the stairs, one is not only reaching the ceiling above, but is also stepping through the thickness of the floor above. Typically this dimension is calculated to be approximately 11-1/2", give or take.

So, as one ascends the stairs, one is traveling approximately 9' (108") vertically. Thus, 14 risers x 7-3/4" = 108-1/2", give or take.

Most inspectors will allow a bit of + or - 'play' throughout a stair run ... so long as it's consistent throughout the stair run. I try to maintain + or - 1/8" throughout

the the median dimension (i.e. 7-3/4" min to 8-1/4" max RISER tolerance means

I would try to make all 7-7/8" to 8-1/8").

It's not as difficult as it may seem. <):-)

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13y ago

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