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Guard Deflection Pass, Fail and or Compliance

Yikes said:
If an inspector doesn't like deflection, that's not a code issue. However, if:
(a) movement of a real suggests not merely deflection, but material weakness or poor connections or inadequate structural deflection, and
(b) the design appears not to have been significantly addressed evaluated in the approved construction documents (no calculations, or inadequate details)
- then the AHJ can request a load test (performance basis), or they can request additional structural details and calcs and material specifications as evidence that the system will not fail under design load. Having received these calcs, the inspector can also request to visually inspect materials, connections, test reports, etc. for conformance to these details and calcs.

I once had a concrete parking garage project with a very poor quality concrete sub. The forms would be stripped off and we'd see voids and pockets that indicated poor vibration. The AHJ rightly requested all kinds of tests, and in the end, they made the contractor load up the deck with a bunch of swimming pools to simulate full vehicle loads.
summer-hot-sale-popular-portable-mini-outdoor.jpg_300x300.jpg
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Thank you Yikes, now I am seeing information that equates to have the engineers take a look and come up with a proof of compliance you can wrap your head around, I like it..
 
If the city inspector were to perform a test that resulted in damage to the railing, he and the city would likely be liable for the repair.

In my experience guardrails designed by architects or left to the contractor typically don’t work. This is preferably addressed during the plan checking process.

If there is a concern about the capacity of the railing the city could request proof of compliance from the applicant. It would be inappropriate to issue a failure notice unless there was specific reason to believe there is a non-compliance. Feels unsafe is not adequate reason to reject the railing.

It is an abuse of power for the inspector to require that the engineer sign a letter stating that the work complies with the code. The inspector can ask for evidence that the design complies, which is either addressed by calculations or testing. The inspector can either verify that the railing was designed according to the design or can accept an inspection report from the engineer or an inspection agency.

If an inspector will not or cannot provide a code section then it is abuse of power.
 
TBZ mentioned that
tbz said:
IG, please explain within the code that you are to apply a 50lb load on an area less than 144 square inches and not flat?

The proper testing method is to apply the 50lb on a 1ft square flat area and if the sphere can pass through an opening created by that force, then it fails.
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I assume the code reference for the 1 sq ft test area is ASCE 7, 4.5.1. The 7-10 ASCE 7 code states that this only applies to intermediate rails and "on an area not to exceed 12" x 12" ..." The 12" square test area is a maximum area that you can test. I suspect that you could game the system if you tried to test a large area.
 
Mark K said:
If the city inspector were to perform a test that resulted in damage to the railing, he and the city would likely be liable for the repair.

In my experience guardrails designed by architects or left to the contractor typically don’t work. This is preferably addressed during the plan checking process.

If there is a concern about the capacity of the railing the city could request proof of compliance from the applicant. It would be inappropriate to issue a failure notice unless there was specific reason to believe there is a non-compliance. Feels unsafe is not adequate reason to reject the railing.

It is an abuse of power for the inspector to require that the engineer sign a letter stating that the work complies with the code. The inspector can ask for evidence that the design complies, which is either addressed by calculations or testing. The inspector can either verify that the railing was designed according to the design or can accept an inspection report from the engineer or an inspection agency.

If an inspector will not or cannot provide a code section then it is abuse of power.
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If I have a 4" sphere, and I can push it through the guard, I am going to fail it. That is not an abuse of power. How is this identified at plan review?
 
I did not say that you could not perform the test although that might be an open question. I did not say that you could not fail a railing if you had proof. I did say that you should be responsible for your actions. I did not say that you could not require proof of compliance.

If instead of applying the maximum load at one time the load was applied slowly it could be possible to see that the test would fail before significant damage were to occur. If you stopped the test at this point it might be possible to develop a cheaper fix than if all of the load were applied at one time resulting in much more damage and a more expensive fix.

My statement was not limited to the 4" sphere test since I understood that the question was more general.

The point was that the city personnel should be responsible for their actions. It is also possible for you to address the issue without personally performing a destructive test.

It is an abuse of power when the inspector requires something that he does not have the authority to require. I am not alone in believing this.
 
Alrighty then Mark K

"If the city inspector were to perform a test that resulted in damage to the railing, he and the city would likely be liable for the repair."
True enough....if I break it I should be responsible. So I'm going to go with "Feels unsafe."

"In my experience guardrails designed by architects or left to the contractor typically don’t work. This is preferably addressed during the plan checking process."
Architects can design houses and contractors can build them but neither can come up with a simple guard rail? The plan checker isn't afforded a hands on experience.

"If there is a concern about the capacity of the railing the city could request proof of compliance from the applicant. It would be inappropriate to issue a failure notice unless there was specific reason to believe there is a non-compliance. Feels unsafe is not adequate reason to reject the railing."
Well I can't break it so I'm stuck with a best guess.

"It is an abuse of power for the inspector to require that the engineer sign a letter stating that the work complies with the code. The inspector can ask for evidence that the design complies, which is either addressed by calculations or testing. The inspector can either verify that the railing was designed according to the design or can accept an inspection report from the engineer or an inspection agency."
An egregious abuse of power is sitting on your hands when they should be writing a correction notice. I would not be satisfied with a letter from an engineer for something that I know is deficient. Next is a report from a testing agency.....so what.....I don't raise an alarm for maybes.....it's not a situation where I expect rebuttal.....fix it.

"If an inspector will not or cannot provide a code section then it is abuse of power."
Balderdash. The occupation is not boilerplate, rote, reaction to what we find. You engineers get the idea that a mere inspector isn't capable of tripping you up. I've seen the Wizard.
 
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Some inspectors exhibit a level of arrogance that is truly amazing and much beyond what engineers can muster. A little humility would be appreciated.

Apparently our system of laws is pushed aside when an individual is appointed as a building inspector. What is the legal authority for this?
 
tbz said:
IG, please explain within the code that you are to apply a 50lb load on an area less than 144 square inches and not flat?

The proper testing method is to apply the 50lb on a 1ft square flat area and if the sphere can pass through an opening created by that force, then it fails.

If you are going to apply a force equal to the area of the sphere, the load would be more around 12-13 lbs, based on the area of the sphere compared to the area of the proper 1ft square area noted in the code.

But, I am going to try and bring people back on focus here, I am not talking about cables when I talk about deflection, I am talking about everything, the entire guard system itself..
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TBZ,
The fundamental goal is protection. The spacing of guards is to protect children. The code requirements for the height and strength of guard rails and guards are clearly delineated in the building codes. The code requirements have evolved to bring about improved safety. The actual test procedure for testing posts, rails and guards, are up to the AHJ.
 
1) GOD:)
2) Mom
3) Building inspectors
142) Architects (man who draws)
501) Congress

As you can see "we" inspectors are pretty high on the list!
Even though you can't trust polling these days?
 
Builder Bob said:
Should be flagged if the deflection of the cabling system allows a gap larger than 4" as required by 1015.4. That was strictly enforced in the tourist town I worked in prior.
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BB, I don't want to get into cables that much here, because the question was meant for everything, not specific to cable infill as more than a few have centered on, I know there is more than a few old posts I did on this forum many moons ago on proper cable enforcement concerning code, but putting a force on a 4" sphere and shoving it through under load and citing 1015.4 is not only wrong in many ways, but simply to state, nothing in 1015.4 is a load test, it is a measurement by tape measure or feeler gauge or other unit. I have over turned every building officials notice of failure ever cited for this that I have encountered where once properly reviewed and checked complied.

Inventing a load test that is not supported by any part of the IRC or IBC is not answer, I would say there are many a pool barrier fence that I can easy shove 4" spheres through every day and have demonstrated it many times.

I will admit poorly designed and tension-ed cable infill is a concern, but that is not the only type of deflection i am focusing on.

I want to take a moment to thank everyone, the information being posted is great stuff.
 
Inspector Gift said:
TBZ,
The fundamental goal is protection. The spacing of guards is to protect children. The code requirements for the height and strength of guard rails and guards are clearly delineated in the building codes. The code requirements have evolved to bring about improved safety. The actual test procedure for testing posts, rails and guards, are up to the AHJ.
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IG,

I am curious on how you are defining that 1015.4 openings is not clearly being defined? especially since yu note that "height and strength" are clear, but then state actual test procedures for testing posts, rails and guards are up to the AHJ?
 
I bet I can get close to 200# and I am not a big guy..I have freaked out more than a few people when I hip check at guard on the fourth floor and it moves quite a bit..And I know a piece of crap when I smell it.....
 
steveray said:
.I have freaked out more than a few people when I hip check at guard on the fourth floor
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I think i have read two reports in 30 yrs about bozos trying to impress people by throwing themselves against office windows. Watch this ... the glass is unbreakable. It’s not the fall, it’s the sudden stop at the bottom.
 
steveray said:
The only thing they could cite would be the 200# and you could prove that with a BIG fish scale......Getting an engineers paper is foolish...
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Per Ch. 17 for in situ testing, it would require a 500 lb load. Who's going to rig that up to a fish scale and how will they generate that load? 2.5 safety factor required.
 
The IRC requires minimum design loads for guards be met.
The IRC does not provide a prescriptive design for guard construction to meet these loads.
All guards must be tested or engineered as alternatives.
DONE.

An inspector is doing a favor if they approve the guard with no 3rd party testing or engineering.
So if someone doesn't like my opinion of a guard, they are absolutely welcome to provide me an engineered design or a tested assembly for me to inspect from. Usually they just strengthen the guards and call for a reinspection to ask for my opinion again.
DONE

I've been involved with a number of code proposals related to this very subject for the 2021 IRC. RB46, RB185, and RB301.
 
As for deflection, here is some guidance that is from the code, but only for plastic composite guards. They must be tested to ASTM D 7032. This test standard is CODE. Here are the deflection limits in that standard for the top rail concentrated load. FYI: there is no deflection limit for the 50 lb infill load. It is a pass/fail based on no disengagement or cracking of any component.

There was a proposal to add these deflection limits during the creation of the 2015 IRC. It was not approved and I have not seen it surface in the last two code development cycles.

The following partial excerpts are copyrighted information owned by ASTM. I am sharing for educational purposes. You can purchase the standard, as I have, at this link:
https://www.astm.org/Standards/D7032.htm There is a lot more information in this standard than what I am providing below.

6.2.4 Concentrated Load Test for Guards—A 500-lbf load (2224 N) shall be applied to the guardrail system at the maximum guardrail height. The load shall be applied at critical locations (for example, top rail midspan between posts, top rail adjacent to a post, top of a single post). In each case, when the applied load reaches 200 lbf (890 N), the deflection at the point of loading shall be recorded. The allowable deflection for the top rail (6.2.4.1) and the post (6.2.4.2), at 200 lbf (890 N), shall not exceed their respective deflection limits:

6.2.4.1 Top Rail—The sum of the rail height, h (in inches), divided by 24 plus the effective rail (guard) length, l (in inches), between the vertical supports divided by 96, or (h/24 + l/96), where the effective rail length is the distance between the edges of the posts. The deflection at the midspan of the top rail is measured relative to the center of the two posts (that is, it does not include post deflection).

6.2.4.2 Post—The effective post height (vertical support) divided by 12, or (h/12). Where the effective post (vertical support) height is the distance from top-of-post to first point of support or first connector of the post to the supporting rim joist (in inches).
 
Thanks Glenn!...Most of my stuff is IRC (we have been drifting back and forth), IBC is easy(er) as there is always a designer to put on the hook, but will not do that for an IRC project if I can help it......
 
steveray said:
Thanks Glenn!...Most of my stuff is IRC (we have been drifting back and forth), IBC is easy(er) as there is always a designer to put on the hook, but will not do that for an IRC project if I can help it......
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I agree. Our society is not prepared for a designer for every deck guard or other household guard. This is why making a fight with a building inspector about guard strength is a bad idea and why I say the inspector is doing a favor to approve any guard. Sometimes when folks look to make me the enemy, I like to remind them of just how helpful I'm actually being.
 
The 4" opening limit in guards is to protect toddlers who are left unattended on high-rise balconies. I don't think the average toddler can push with a 50 pound force.
 
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