“The triangular area formed by a tread, riser and guard should not allow passage of a 6- inch-diameter sphere.”
What it doesn’t say is whether that’s at the start of the tread (which I suspect) or the back of the tread. It seems if it’s the back of the tread, the guard is going to be very close to the tread…
You graphic is different than the one in the training. Your graphic suggests the ball rests against the riser for the clearance test. The training isn’t clear on resting against the riser, or setting on the edge of the tread above the riser below it.
I am not speaking for Tom but, I think Tom’s reference to ambiguous meaning was that, we as InterNACHI CPI’s do not inspect to and refer to code, Brain.
Ambiguous in that I’m looking for “go here, do that”! Some of these requirements/codes get to be a LOT of little things to know. Not being someone that installs handrails or guards, this is new information to me. I can see a triangle formed by either the back riser and the tread, or the front riser and the tread. Then there’s idea that 6" seems awfully small - or puts the guard close to the tread - not actually looking at a stair/guard installation. There may be more clearance than my mind is envisioning.
Also, you can’t rule out the “Tom’s a hardhead” angle!
But, looking at it in the lens of safety, and a 6" ball shouldn’t pass thru any part of any riser/tread/guard triangle puts it to bed.
I don’t understand the confusion here. The sphere should initially be touching the tread (Adjacent) and the riser (Opposite). If it does not touch the guard rail (Hypotenuse) to prevent it from passing through… IT FAILS!
Anyway, we are not code inspectors. To say we do not refer to code or inspect to code is just not true. Of course we do, code is a reference point or touchstone for all of us. Commonly referred to as “modern building standards”.
Sorry, Brian. I misspelled your name.
Not the strongest speller. Don’t take it personally.
One inspector did several years ago and disparaged me on the MB for years. What an ass. He’s retired now. Good riddens.