• Welcome to the new and improved Building Code Forum. We appreciate you being here and hope that you are getting the information that you need concerning all codes of the building trades. This is a free forum to the public due to the generosity of the Sawhorses, Corporate Supporters and Supporters who have upgraded their accounts. If you would like to have improved access to the forum please upgrade to Sawhorse by first logging in then clicking here: Upgrades

Circular stair? Help with CBC R311.7.3 needed

J

Jonathan

Member
Joined
Jul 24, 2010
Messages
23
Location
Palm Desert, CA
Hello, Am doing an exterior stair which serves the garage and entry levels of a residence in ca.It's a continuous winder or circular stair - see pdf plan attached.I would like to have 4" risers and a 16" tread (tread shown of diagram is a little less) and would like for someone to let me know if I am implementing the code correctly.I have included the dimensions and locations on the stair drawing provided. Tread depth measered perpendicular to leading edge to next vertical riser and 12 inches from the side where the winders are narrower. Do I have this "walkline" correct on the drawing?Best to all,Jonathan

View attachment 1790

code stair detail 11 x 17.pdf

code stair detail 11 x 17.pdf
 
Their figure 13 shows a tread depth measurement method different from the code "at a right angle to the tread's leading edge"

CBC R311.7.4.2 reads:

The minimum tread depth shall be 10 inches. 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....

Looks like they are measuring the arc at 12" in from the inside radius

or perpendicular to a line bisecting the angle between risers?

mark handler said:
That is a winding not Circular stair.The code identifies winding and spiral stairs, not Circular stairs

FYI

http://www.abqstair.com/wp-content/uploads/2012/06/SMAVisualInterpretationIRC2009ecopy_1__1_.pdf
Click to expand...
 
I think it's ok with drawing and code is looking ok but who make this drawing. You made this by a architect or you consulted with someone.
 
You must log in or register to reply here.
Top