OK, so we all know about the 4″ sphere test.
What is the minimum spacing that brings that rule into play?
In other words, If I have 32″ between members, a 4″ ball will obviously pass through (with 28″ to spare!). But the 4″ sphere rule doesn’t apply, I guess because a child cannot get their torso stuck on one side and their head on the other.
If I have 28″ between members, same thing; 4″ ball will pass through, but 4″ ball rule doesn’t apply.
24″? 20″? 16″? 12″? 4 1/8″?
k
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Replies
Around here the rule applies to decks, landings, or stair treads more than 30" above adjacent grade or floor. If you're more than the 30" limit then the 4" rule applies to every area of the railing below the 36" rail cap. If your walking surface is less than 30" above adjacent then no guardrail at all is required, although you may need a grab rail if there are stairs.
right, but my question is about the member spacing, not when you need members.
For instance, I did a handrail a long time ago when there was no significant drop-off over the edge. But the client wanted an intermediate horizontal anyway, just to kind of discourage her grandkids from deviating from the path and crushing her azaleas.
I put it in, dividing the space under the handrail in two, with spaces of about 16".
I figured no kid would get stuck in a 16" space, so no prob.
But what if the client had asked for two intermediate horizontals? that would have left three spaces of approx. 11". would that have been up to code?
or what if the client wanted three intermediate horizontals? then we'd have four spaces of approx 8". almost certainly not safe or up to code.
So my question is, what is the minimum size spacing that brings the 4" ball rule into play? 16"? 11? 8"?
k
Edited 3/9/2009 1:44 am ET by KFC
Edited 3/9/2009 1:47 am ET by KFC
Now I understand. That has never come up for me. I have built a few guardrails with a cap rail and 1 or 2 horizontals evenly spaced. I would think that gaps in the 6-8" range would be dangerous to kids.
My guess is there's almost nothing a determined kid can't turn to trouble.
Grandson's favorite word seems to be "Uh-oh"
Joe H
I managed to climb our stone chimney all the way to the top when I was about 8 YO.That was about the same period of my life when I used Mom's umbrella for a parachute off the roof.Once.
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I'm glad I have a daughter.
I'm glad I have a daughter.
So's my son, or grandson.
How old?
Joe H
"I'm glad I have a daughter."Just wait til you have to pay for a wedding. :)BruceT
when I used Mom's umbrella for a parachute off the roof.
You're going to give yourself credit for coming up with an early version of fall protection, right? :)'Man who say it cannot be done should not interrupt man doing it' ~ Chinese proverb
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LOL, I could have used fall protection. I just jumped into space 14' up there holding the handle. There was a wonderfull sensation of floating lightly for all of half a second.Then the thing turned inside out and my descent accelerated rapidly. I think I had the thought just before I hit the ground that things must work differently in the cartoons on TV somehow.I had pains in my shins for a couple weeks but never admitted how her umbrella got damaged.
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Well, I'd recommend skydiving. You get that same sensation of lightly floating.If all goes well, you don't get that jarring impact.But the float down, after the chute opens, is the most peaceful feeling I think I've ever experienced.Gonna take your advice and not try the umbrella trick though :)
'Man who say it cannot be done should not interrupt man doing it' ~ Chinese proverb
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Yeah, your Mom will kill ya if you survive and she finds out.
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Ditto on the skydiving thing. Just the wind at that height. Makes one realize how much regular background noise there is on the ground.
twenty-plus years later though, i'm fine with the noise
Just like Mary Poppins? Mary Piffin?
>>>OK, so we all know about the 4" sphere test.
Hhhmmmmm I dunno... he's a regular around here...
good sense of humour, lotsa wife jokes... don't know about the
4" part though.... is this going to get a bit personal!??
TMI I say.....
;)
Scott.
4" diameter? ;)
k
Oh my.....
that's what she said...
k
ps- wanna weigh in on the actual question?
Go find the kid with the biggest head you ever saw, measure it from every concievable place to find the major focii, add an inch for good measure. If the BI gives ya a raft, grab the kid, stuff his or her big fat head in the space, rotate on many axises and say " see? even this fat headed kid can't get stuck"
Might wanna buy the kid some icecream and keep his/her parents out of earshot.Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations
They kill Prophets, for Profits.
As I understand this deal - it isn't the head size that makes for th emin 4" Kids would find a way to get the BODY through the gap, but not the ehad.Then they slip and fall, dangling the body while head is still retained resulting in strangulation or broken neck. I'd think most heads would be fine with a 6" Sphere test
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Thats why I said the kid with the fattest head,if he can't get stuck, no others will.Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations
They kill Prophets, for Profits.
You missed it. All the heads will get stuck. It's the body that can fall thru
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Yeah, I missed it. First day back on a 14/12 facing some dormers with Azek, my mind is a jittery as my legs. Too much time off this winter.
Let me phrase it this way, IF the BODY can get thru, and the head can get thru ( which we determined by using fat head boy) then NOTHING can get stuck.
(G)Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations
They kill Prophets, for Profits.
Believe it or not, there are claims that kids manage to get their melons through 4". Partly to do with the cranial sutures still being flexible enough for some of them to squeeeeeeze through. Unfortunately, where the head goes, the body follows.
One of those code issues that changes every few years. 4" spacing, then wire grilles, then wire grilles turned 45 degrees to discourage climbing. Now i think it's back to the 4" spacing.
Your umbrella story explains a lot. <g>
unfortunately, mine involved letting go of the swing at the business end in a superman moment . . . found out kryptonite is latin for gravity
and gravity is short for 'mouth full of gravel"!I was on a tailgate when I was maybe 12-13 as the truck was picking up speed down the lane. I decided I really didn't want to go after all and stepped off, figuring I could run at first and then slow down and then turn to walk back home a bit.I ran all right! First 2-3 steps were probably 20' long each, but my torso was still lurching forward faster than my legs could keep up. There was a sort of superman feeling to running that fast - until I went down
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As I understand this deal - it isn't the head size that makes for th emin 4" Kids would find a way to get the BODY through the gap, but not the ehad.
Then they slip and fall, dangling the body while head is still retained resulting in strangulation or broken neck.
Common sense has always told me to make the open spaces of any vertical plane along a walkway either too small to get a head through, or so big that an entire toddler would just slip through. But, (if I hear you right), basically, if there is no drop off, you could build a railing with nooses for infill, and code wouldn't have anything to say.
And if there is a drop off, then it's back to Sphere's 4" diameter.
k
I think it was only a question of who got to that one first...
He just left off the 6' before the 4". Everything else is proportional.Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations
They kill Prophets, for Profits.
It's not the spacing between members that drives it but rather whether the code requires a railing or guard at all. If so, then you cannot exceed 3 15/16" between vertical members and you can't have horizontals that would create a 'ladder' effect.
So if a railing or guard is NOT required (for instance, an exterior drop of < 30" off a raised porch - YMMV depending on your code) you can do anything you want.
Jeff
Right, hence the infill with nooses is ok if no drop-off comment.
I still don't like the idea of a 6" gap between a couple of members next to a walkway, I can just see some kid getting their noggin stuck in there, getting panicked and causing some damage, even if they're not literally hanging.
But the consensus is that code isn't concerned with that. I'm (slowly) coming around to that realization. I apologize to everyone who said as much, and then I protested that they didn't understand my question.
And hey, here's another can of worms. I think the ladder effect rule is no longer in IRC.
k