Stair treads can't find

I have been looking in my books and need to find where it shows that the stair tread should be 11 inched. I could be missing it. Can some one help me find it? Or let me know what book it is in.

I looked in the deck inspection book


Im thinking a google search of stair tread specifications might help…


R311.7.5.2 Treads. The tread depth shall be not less than 10 inches (254 mm). 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 greatest tread depth within any flight of stairs shall not exceed the smallest by more than 3/8 inch (9.5 mm).

From the Google


@afrydenlund is right, but we do not know what year the home was built.
2018 IRC


You can use that number (minimum 10 inches) for the last 20 years and quite probably much earlier. My house was built in '62 and complies.

Winder treads are different. ten inches at the walk line (12 inches from the outside edge of the tread) and a minimum of 6 inches at the narrowest part of the tread.

Not much you can say about code in a home inspection report. I usually call out “modern safety standards.” But I generally only measure winders (accident waiting to happen w kids) and riser height when there is a noticeable variation (trip hazard).


I agree with, Bob. It has been that way for a long time.


Thank you all for your help. I do appreciate your time and help. It was very helpful.

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11" is commercial with a 7" riser and 10" and 7&3/4 is residential. All you need to remember.


The riser and tread dimensions can vary with location. In my state the riser can be 8 1/4" and the tread minimum 9" So double check your local rules.

You did not specify your location so I have no idea where you are, maybe not even on this planet :smiley: