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Catch all in chapter 1

The building official is required to approve a design that complies with the adopted regulations. If the design does not comply with the approved regulations the building official is required to withold approval. The building official is not allowed to withold approval because the design does not comply with some requirement not formally adopted by the jurisdiction. Thus deflection criteria cannot be the basis for witholding approval.

Please clarify why basing the design on a 8 foot segment is a problem. While the total load in a 24 foot long guard rail will have a greater overall force to resist, because of the regular spacing of vertical elements calculations can typically be based on a shorter segment.
 
Mark,

I am not saying that deflection is directly written in to the code for guards. I will only ask you this, if it is not an assumed element of restriction at what point does one conclude that the 200lb point load has failed?

Remember, one can do either calcs or testing.

Please explain failure point.
 
By calculation you need only show that the allowable stresses written into the code have not been exceeded. You do not need to perform a deflection calculation. When justifying the design by calculations you are concerned with conformance to the code which is different than failure. The calculated capacities assume factors of safety to account for variations in material properties and other things.

It should be noted that the code does not formally define a testing protocol, but in general failure could be assumed to occur if the test assembly was not able to sustain the test load for several minutes. In many cases failure would be assumed to occur if there was significant permanent deflection after the load was removed.

Tests performed on a prototype such as the ASTM standards referenced would likely assume some factors of safety while tests of the actual installed guard rail could be tested for the code specified loads. My guess is that it would be very hard for anybody to excert a load greater than 50 plf on a guard rail.

In some situations the 50 plf load will be more critical than the 200 pound point load.

Because testing of guard rails is not addressed in the code it would be considered an alternate means of compliance to be negotiated between the applicant and the building official. The building official cannot require testing if the applicant can show that the design works by calculation.
 
Mark K said:
Because testing of guard rails is not addressed in the code it would be considered an alternate means of compliance to be negotiated between the applicant and the building official. The building official cannot require testing if the applicant can show that the design works by calculation.
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Does this mean that the calculations in themselves are sufficient evidence of compliance?

R104.11.1 Tests. Whenever there is insufficient evidence of compliance with the provisions of this code, or evidence that a material or method does not conform to the requirements of this code, or in order to substantiate claims for alternative materials or methods, the building official shall have the authority to require tests as evidence of compliance to be made at no expense to the jurisdiction. Test methods shall be as specified in this code or by other recognized test standards. In the absence of recognized and accepted test methods, the building official shall approve the testing procedures. Tests shall be performed by an approved agency. Reports of such tests shall be retained by the building official for the period required for retention of public records.
 
Compliance of the design is typically documented by means of calculations without any testing. This is the default condition. Calculations which comply with the code are considered sufficient evidence of compliance unless the situations listed in R104.11 occur. Testing is seldom done.
 
I’m glad Fire Marshall Bill was able to answer your question but regardless, wouldn’t the simplest thing be to get the professional who designed the rail to observe it to ensure that it was constructed per their design and if it is, to write a letter to the AHJ stating that? The conflict here seems to be who gets to decide what is unsafe. Sorry, but I would put more stock in an engineer than a building inspector in this case.
 
Ok Mark,

Let's say a building official is given a signed and sealed document by 2 independant engineering firms saying that the calculations and design of the guard is compliant.

Let's say one engineer visits the site and reviews the installation and says it is installed per the drawings correclty and though it moves a good bit he could only recommend testing to verify.

Now when you go up to the guard and grab it and lean on it, it moves close to 2 inches off vertical. It returns to vertical when released. less than 200lbs of point load.

In your opinion do you feel that the inspector CAN or CAN NOT cite R104.11.1?

R104.11.1 Tests. Whenever there is insufficient evidence of compliance with the provisions of this code, or evidence that a material or method does not conform to the requirements of this code, or in order to substantiate claims for alternative materials or methods, the building official shall have the authority to require tests as evidence of compliance to be made at no expense to the jurisdiction. Test methods shall be as specified in this code or by other recognized test standards. In the absence of recognized and accepted test methods, the building official shall approve the testing procedures. Tests shall be performed by an approved agency. Reports of such tests shall be retained by the building official for the period required for retention of public records.
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Just because I can I always like to take an argument to the outer limits of reasonable.

Lets say an architect and an engineer both sign seal and tbz delivers a unique but compliant guard and rail system

(passes the 50 and 200 pound design and field test)

the unique guard rail looks alot like a 2" diameter bungee chord and contains a equally flexible guard made of Bungee Netting.

that when loads are applied retains a 4" diam sphere (guard) and deflects to 89.95 degrees from vertical to hotizontal then snaps the

poor load applicant back to vertical and perhaps beyond.

the math shows all applicable loads are sustained and sucessfully resisted.

but because no deflection criteria is specified, just to be amused, he approves it?

Rails By BunGee (could it happen in your jurisdiction)

Now lets say you have opposing guard and rail BunGee R- US Guards on opposite sides of a walkway.

Wuold you classifiy it as an amusement ride?

I thought of this while watching Hulk Hogan on WWE
 
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I am assuming that the building department has reviewed the calculations and concurs that they were properly performed..

If the magnitude of the guardrail deflection caused the building official to be concerned about the strength of the guard rail it would be appropriate to verify that the railing was installed in accordance with the approved documents. It might also be appropriate to review the approved drawings and the calculations.

If there is a concern about the design it would always be appropriate to bring the concern to the attention of the engineer. While there is often no problem these reports have on occasion helped to identify a problem.

In the situation that you referred to where the rail deflected 2 inches when somebody leaned on it I would suggest that either the vertical post was undersized, the connection at the base was loose, or the structure at the base was unable to resist the applied loads. This should be resolved without trying to invent deflection criteria.

If the calculations submitted with the permit included deflection calculations and the field deflection appeared significantly larger than the calculated value, it might be a sign that something was fishy. Deflection calculations for wood construction might vary significantly because of wood shrinkage, loose bolts, etc even if constructed per the design. So the fact that deflections vary would not necessarily indicate a safety problem. Never the less it would not be inappropriate to verify if it was installed correctly.

If the guard rail had the necessary strength, deflected an amount that was bothersome the Owner might want to have the railing stiffened up but it would not be a code issue. It would be a contractual issue.

If the building department’s inspectors were unable to verify how the guard rail support was constructed, irregardless of the deflection, the inspector could ask the applicant to either expose the work so it could be inspected or to perform a test. I would expect that in most cases the applicant would prefer to expose the work. Care should be used not to abuse this option.

Personally I believe that a lot of guardrails do not comply with the code and more attention should be given to them during permitting and inspection. Having said that it is my perception that we have relatively few failures of guardrails. Thus more attention should be paid to guardrails but we need not be obsessive on this topic. There are other areas of code enforcement that also deserve more attention.

Rails by BunGee is a case that I have purposely avoided because, as stated, it is not very reasonable, if it was that flexible most clients would not find it acceptable and would have it replaced, and the code does not address this scenario. When the code does not regulate a scenario the building official cannot do much.

Somehow the avatar (Leonardo if I am right) of the author of the BunGee rail idea seems as relevant as watching Hulk Hogan.

When the loads are applied to the BunGee rail and the deflections were large then the engineer should consider the geometric nonlinearities of the guard rail. The net result is that the system probably would not work. Also note that the proposed scenario assumes impact loading while the code only requires static loading. It is assumed that the code loads account for normally expected impact loadings, not Hulk Hogan running into the rail.

Intellectually I am willing to consider that there might be a feasible scenario where the code would allow a clearly unsafe condition to occur. Let us assume that a significant number of experts agree that the risk is severe and is likely. In such a situation the building official may be limited to writing a letter informing the applicant about the risk and noting the inability of the code to prohibit the problem. If you felt the need to do more I would suggest that you have your concern peer reviewed by several technical experts and talking to the city or county attorney about your options.

Having said that in my 35+ years I do not believe that I have seen a situation that was blatant enough to warrant going beyond a letter of concern. In my experience significant safety concerns can be addressed using the provisions in the code. This is not to say that the code is perfect but rather the blatant problems have been pretty well addressed.
 
Mark,

Great post please don't feel like I am jumping on you. This level of deflection is a very common occurance on long straight spans and happens a lot more than you think.

Lets get back to my question above, with a 2" sway you agree that the inspector has the authority to request and verify testing be done.

So here is my next question for you, ASTM 935, ASTM 985 & ES-AC273 have deflection limits wriiten in to the testing standard. Since the building code does not have deflection criteria does this mean when testing that these specifications are allowed not to be met nor be tested for?

Secondly, though there are many reasons that deflection can occur, a good portion of them are not the guard but the sub-structure being mounted too and I agree there.

So let's say the guard passes testing for only the parameters in the building code, but fails the deflection criteria in the testing standard not in the code, do you feel it should pass or fail?

And I am pointing out ASTM 935, 985 and ES-AC273, are there other testing standards for guards you use or know of, because these are the common specified within construction documents?

Lastly, when documentation is submitted for a building permit to the AHJ a copy of the specification documentation is submitted with it, not just drawings, in many documents it is common to have listed within the documentation that testing be done. We see this very often, I know for fact on the last 30 projects I have seen that the owner accepted engineering calcs and did not have the testing done because of the very high cost. As inspectors if in the documents are you requesting to see test results? or are you accepting engineering documentation as compliance? Again this is a question because the criteria is listed in the documentation to be done.

Again not looking to put you or anyone else on the spot though it might look that way, just trying get an understanding of how the testing standard would be used and applied in your views.

Again thank you for your responses, they are all very helpful.
 
Mark K; Hulk Hogan was referenced per my beyond reasonable approach if I had wanted class introduced I would have referred to Ali

both gentlemen are enclosed by guard rail systems that at times are required to keep them vertical.

and thanks for recognizing "Leonardo"

I chose that because when my now 6'-4 270 pound son was much smaller younger and impressionable I actually had him

beleiving I used to be Leonardo the Ninja Turtle -

so that avatar is a family tradition of embarasment that I get to use against an individual that could crush my spine if he wasn't so gentle.

two more posts and this thread could approach "Attic Stares" status

here is an Icc es Aceptance criteria report that cover the isue with a fine layer of mud

http://www.icc-es.org/criteria/pdf_files/ac273.pdf

(Leo the other mmasked man)

tbz the ICC report actually introduces deflection limits acceptability that would allow inspectors and installers alike a evenings sleep
 
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If the railing is deflecting, does it "transfer this load through the supports to the structure" (1607.7.1)?

It would seem that in the bungee scenario, the load is not being transferred to the structure, but rather "absorbed" by the guard.

Not being an engineer, I would say the posts would have to be rigid to transfer the load to the structure.

I could be absolutely wrong, hoping an engineer can shed some light on how the load is transferred, or if it can also be "absorbed". Or maybe I am completely off-base.
 
No I said the inspector has the authority and reason to ask questions not require testing. The focus of the inspectors concern is on strength not deflection.

The inspector does not have the authority to require testing if the owner would prefer to expose the construction so it can be verified. The owner also has the option to replace or repair as opposed to performing testing. I would expect that testing would be rarely used.

It would be inappropriate to impose the deflection criteria in ASTM E935 and E985 or other testing protocol. Imposing the deflection criteria in the ASTM standards would be equivalent to the inspector illegally modifying the code. In fact the testing criteria for strength in these standards might be more conservative than needed since you are testing the actual installation as opposed to a prototype..

The testing in the specifications typically refers to special inspections as required in Chapter 17, other material tests required in the code (not R104.11), and other inspections required in the specifications.

The code assumes that compliance of design for guard rails will be shown by means of calculations not testing. There is no provision in the code that references ASTM E985, E935, or ICC-ES AC 273. They can only be used as an alternate means of compliance. Building official can allow alternate means of compliance but cannot require that the design use an alternate means of compliance if the applicant prefers a code compliant design.

Compliance with ICC-ES acceptance criteria can not be required. They can help provide the building official with guidance that he can use to decide if a proposed alternate is acceptable. The applicant can always use a code compliant design. ICC-ES acceptance criteria are often based on criteria in excess of code and at times have had a negative impact on code compliant products.

Note that this thread is apparently dealing with commercial construction but R104.11 is applicable to residential construction.

It is my belief that when questions of this natuer come up that the inspector consult with a engineer working for the buidling department. I believe that much of this discussion is related to a lack of knowlege regarding calculations and engineering principles.

It also appears that some individuals want to find a way to impose a deflection criteria that is not in the adopted code. This is not permitted.
 
tbz brought R104.11 into the thread at this juncture.

tbz said:
AS most of you know inspectors come in all shorts of opinions, with that said putting a stall on a project will often get questionable compliant items changed rather than delay the C/O.AS you know many will just give in rather than say they are correct.

An example recently.

South Central PA,

Inspector was failing an IRC residential guard on stairs with handrail on top because the 1/2" x 2" flat bar was on top of another flat bar 1/2" x 1" sitting on top of balusters.

The inspector was stating that the double stacked flatbar ment it was a type II and did not comply with type II, insisted that it was not a type I which it was.

Well this project would have required a few hundred feet to be replaced,

The builder simply said to the fabricator rip it all out you can't be right the inspector said so.

2 days and an interp from the ICC later and both the inspector and the builder were able to now see that this is allowed. From what I heard the inspector had others before this remove and replace on smaller projects and it must of been simpler for the builder to just change it.

So the long point to my short question is just because you are right does not mean much sometimes.

Cheer up FM the advertisers will not let it go just 4.
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I see Jar spawned a holiday avatar,

Ok Mark, I stand corrected, the inspector does not have the authority to request testing,

For the record in the past year I have had some commercial and some residential come over my desk with this issue so in my questions

everyone should feel free to input, I posted under the commercial section here because the most current issue is in California and they use IBC for IRC.

So, for product that does not comply with calcs, the code allows the submitter the alternative method to test for compliance. I got it, its an additional method for alternative products.

So with that said, am I correct in saying then that even though the documentation submitted notes shop drawings with calculations and testing to be done, that the inspector can only request the calculations and have the AHJ engineer review for compliance? If the AHJ engineer agrees that the guard design and installation complies with the submittals then stamp it.

Which leads to a simple course of action on the inspectors side for concern is the letter of concern in the file then, correct?

The inspectors way of saying I don't like it, but from what has been presented and reviewed it complies and therefore approved.

Thanks for the input everyone, it helps on multipal levels.

And Mark thanks for the responses they are very informative.

Lastly, FM I told you they would get at least 1, have not see a reply cheer up at least their not the Cowboys.
 
tbz said:
Good afternoon everyone,I know it exists, just not sure were it is, but here is what I am looking for.

Let me state this is not my work, but a member of my association out west.

The guard is installed, it moves when you lean on it.

The engineer stamp it, the height is correct, opening sizes are good but it has a shimmy.

The inspector is claiming its not safe and is not signing off on it,

For the record I don't blame the inspector, however they won't cite a violation number and just notes fails for being unsafe.

Now that you have gotten yourself back up from the floor, could you give me a little direction.

Thank you
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I hate to jump in late, but...

Give the contractor the option of 1. securing the handrail against movement or 2. employing an independent testing agency to field test the current assembly configuration for its ability to resist all required loads.
 
2006 IBC, Section 104.4: The building official is authorized to engage such expert opinion as deemed necessary to report upon unusual technical issues that arise, ...
 
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