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16' Garage Door Headers

Re: 16' Garage Door Headers

kilitact said:
heaven??
spank my shared AA
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?? might be fun ;) if your saying you can only do a half a.. job has a code official, how do you feel?? :?

I do a great job as a B.O., thanks.

Wonderful thing about life is that there are so many perspectives.

Too bad you are unwilling to accept that your perspective isn't the only valid one.

Nuff of this foolishness, I'm done.
 
Re: 16' Garage Door Headers

RickAstoria said:
For your information, the answer to the question regarding maximum tensile force that I gave you is 34 Kips.With a factor of safety of 2 - you would spec a steel structural wire rope for 68 Kips which is 34 tons.

A minimum of 7/8" diameter steel wire rope with Class A zinc coating would be required as it has a Minimum breaking strength of 35 tons.

I would go with 1" diameter. Of course, this is for a very limited condition based on the given condition of the equation. Real life situation would be more complicated then that. I gave you a more easier question to answer if you knew something about it.

Yet, I am weary of designing a cable-supported roof system without an engineer. It gets into some very hairy stuff.
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I'm getting a little late to the party here, so nobody may care about my response or my opinions.

Rick, actually there are 3 discrete components, and therefore (in your example) 3 discrete stresses in the cables, and that's very important. Yes, the maximum stress is of course in the cable on the right hand side, and my calculations yielded 34.05K. The cable on the left hand side experiences 33.64K, and of course the vertical cable (or whatever the suspending element may be) suspending the 10K load is not carrying any horizontal load components, so is only under 10K of tensile stress.

And if you, as a building designer, are designing cable roof systems and they are being accepted by any jurisdiction

in the country, I would like to see the state law regulating the practice of engineering for the state in which you are doing work, and the code amendments for the jurisdiction that is accepting your design. Your statement about "usually" consulting an engineer when designing such systems frightens me to the core.

For anyone who cares, I think it is perfectly acceptable for any building professional to question the design assumptions, the calculations, the drawings, etc. for any submittal that comes through their jurisdiction, regardless of who designs or submits it. Doing so does not "make you liable for the design", or "responsible for the work"; that is B.S. Questioning any submittal is not only acceptable, but the responsible thing to do if you suspect something is not right.

Of course I also agree with those who say that if the building professional does not feel comfortable or qualified to challenge a design, they are certainly not obligated to do so.
 
Re: 16' Garage Door Headers

texasbo said:
I'm getting a little late to the party here, so nobody may care about my response or my opinions.Rick, actually there are 3 discrete components, and therefore (in your example) 3 discrete stresses in the cables, and that's very important. Yes, the maximum stress is of course in the cable on the right hand side, and my calculations yielded 34.05K. The cable on the left hand side experiences 33.64K, and of course the vertical cable (or whatever the suspending element may be) suspending the 10K load is not carrying any horizontal load components, so is only under 10K of tensile stress.

And if you, as a building designer, are designing cable roof systems and they are being accepted by any jurisdiction

in the country, I would like to see the state law regulating the practice of engineering for the state in which you are doing work, and the code amendments for the jurisdiction that is accepting your design. Your statement about "usually" consulting an engineer when designing such systems frightens me to the core.

For anyone who cares, I think it is perfectly acceptable for any building professional to question the design assumptions, the calculations, the drawings, etc. for any submittal that comes through their jurisdiction, regardless of who designs or submits it. Doing so does not "make you liable for the design", or "responsible for the work"; that is B.S. Questioning any submittal is not only acceptable, but the responsible thing to do if you suspect something is not right.

Of course I also agree with those who say that if the building professional does not feel comfortable or qualified to challenge a design, they are certainly not obligated to do so.
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We are talking maximum tensile force which is the most critical thing. As that is the peak load. Nothing is said of specific points because certain points will have higher force and the cable needs to not break at the maximum stress. You numbers agree with my numbers. I agree and you point out some very good points. I have the answer to the question itself. I do understand that there is potential for all three load stress components to be concentrated to a single point at a "Moment" and other factors including flutter and so on. All of which is outside the scope of the single question. Real life, is much more then that on question such as a complete roof system.

Note: IIRC - Single Concentrated Load System. I think that was what I said.

When I say, I usually "consulting an engineer" for this kind of stuff is that sophisticated calcs like this - I may perform but only if I feel comfortable designing such a system. as I said, I would likely want a "engineer" on-board when designing a system with such a roof system. It isn't an easy system to design for. Something I might do on an occasion might be a fairly simple truss while at other times may have an engineer. Cable-supported roof systems are a bit on the weary side so I am not going to tackle on this without an engineer until I am comfortable with the math involved for an entire roof system where I can competently design the entire system without fear of screwing up any worse then a competent engineer in such system. Point: Same standard of Professional Care.

For clarity of statute that does put such an exemption - ORS 672.060 and I have email records with response from the governing agency - OSBEELS. This doesn't mean I can use the engineer title or conduct the practicing of applying the mathematical, physical and engineering sciences (eg. performing structural calcs) independent of design work involving an exempt building.

In short, if it is incidental to designing an exempt building(s) then it is not a practice violation to prepare structural and infrastructural calculations in accordance with accepted standards of applying the mathematical, physical and engineering science to the design, planning & specification to & of structural and infrastructural systems and components of such building(s).

I do not disagree about a Building Official or Plan Reviewer from questioning a submittal. If you have question and you do not have the education or experience to properly check the calcs for the matter, I would think the prudent thing is to get a professional who is qualified to check the calcs under your supervision/observation and report finding so you can make the appropriate next step. Getting an expert opinion to back your 'gut feeling'. Then you can approach the person responsible for the plans. It is questioning the submittal but in how you do it.

It is a matter of best practices in reviewing plans and applying it. What if your gut feeling is wrong?
 
Re: 16' Garage Door Headers

WOW! Sixteen pages on a garage door header question......... :?

Did you ever get a definitive answer to your question VP?
 
Re: 16' Garage Door Headers

fatboy said:
WOW! Sixteen pages on a garage door header question......... :? Did you ever get a definitive answer to your question VP?
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Yeah, I gave header sizes, appropriate for this span, some pages ago. Another person did too.
 
Re: 16' Garage Door Headers

TJacobs said:
I had to moderate this topic. It was getting out of hand. I moved all previous posts that had nothing to do with the subject.If you want to debate what a design professional is, go to:

http://inspectpa.com/phpbb/viewtopic.php?f=44&t=831

If it does not apply to 16' Garage Door Headers, don't post it here.
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Your post appears to be about moderation and not garage door headers...just saying.
 
Re: 16' Garage Door Headers

brudgers said:
TJacobs said:
I had to moderate this topic. It was getting out of hand. I moved all previous posts that had nothing to do with the subject.If you want to debate what a design professional is, go to:

http://inspectpa.com/phpbb/viewtopic.php?f=44&t=831

If it does not apply to 16' Garage Door Headers, don't post it here.
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Your post appears to be about moderation and not garage door headers...just saying.

I guess you zinged me... :roll:
 
Re: 16' Garage Door Headers

TJacobs said:
brudgers said:
TJacobs said:
I had to moderate this topic. It was getting out of hand. I moved all previous posts that had nothing to do with the subject.If you want to debate what a design professional is, go to:

http://inspectpa.com/phpbb/viewtopic.php?f=44&t=831

If it does not apply to 16' Garage Door Headers, don't post it here.
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Your post appears to be about moderation and not garage door headers...just saying.
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I guess you zinged me... :roll:

Ok. That works.
 
Re: 16' Garage Door Headers

The whole 16' opening issue largely depends on if it's a bearing or non bearing opening..

load bearing (like a hip roof).. you need an engineered solution (which can come from the manufacturer without requiring the entire stucture to be engineered)... non load bearing, the biggest issue will be "will the header sag and the door won't open".. LVL's are an engineered solution to the problem.
 
Re: 16' Garage Door Headers

Peach,

I suppose if this was something other than a overhead garage door that a sagging header may prohibit the door from operating properly. An overhead door does not fit within the opening, a sagging header would have virtually zero impact on the door operating.
 
Re: 16' Garage Door Headers

incognito wrote;

Peach,I suppose if this was something other than a overhead garage door that a sagging header may prohibit the door from operating properly. An overhead door does not fit within the opening, a sagging header would have virtually zero impact on the door operating.
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A sagging header can impact an overheads doors operation by putting stress on the members that are use not only as support of the header, kings, jacks etc, but also as support for the brackets and runners for the door. Additionally this sag can impact other members that are supported by this header.
 
Re: 16' Garage Door Headers

incognito said:
Peach,I suppose if this was something other than a overhead garage door that a sagging header may prohibit the door from operating properly. An overhead door does not fit within the opening, a sagging header would have virtually zero impact on the door operating.
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Incorrect
 
Re: 16' Garage Door Headers

Jar said:
Incorrect
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How is she incorrect? I'd say 99% of garage doors sit behind the header, both roll up and sliding barn doors, now these outswing garage doors sit under the header, and a sagging header would be a problem, they are becoming popular in high end homes, click the videos down the page, they are really neat.
 
Re: 16' Garage Door Headers

The center spring mounting plate to most roll up doors is mounted dead center of the header. As it sags it throws the door out of balance and sometimes causes binding of the outer rollers.
 
Re: 16' Garage Door Headers

Sometimes, might, can....blah,blah, blah. Try rarely does a overhead garage door header sag enough to impact the operation of an overhead door.
 
Re: 16' Garage Door Headers

I went out and looked at mine and I see Jar's point, but I did notice that the springs are on one side and the attachment bracket is one quarter of the way over from the right with a spring on each side. I wonder if they do that because of Jar's concern? Obviously there would be half the impact one quarter the way over than there would be at the center if the header did sag. The next time I talk to my garage door guy I'll ask him if they do that to reduce the impact of any header sag. I've never noticed that before, thanks for pointing it out Jar.
 
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Re: 16' Garage Door Headers

Incognito wrote;

I suppose if this was something other than an overhead garage door that a sagging header may prohibit the door from operating properly. An overhead door does not fit within the opening; a sagging header would have virtually zero impact on the door operating.
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Incognito, there are other methods of installing overhead doors and I could see where one could design it to be structurally independent of the garage door header, I haven’t seen this, but in thinking about it I could see where it can be done. The other part of the equation is that the header is part of a lateral force resisting system. This design could use a different method of transferring the lateral force so that the header sag wouldn’t have an overall negative impact. So, thanks for pointing that out, sometimes we need to open or have opened our ears to other possibilities.

mtlogcabin wrote;

It wasn't all about garage door headers :roll:
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How very true. :roll:
 
Re: 16' Garage Door Headers

CA: That is a torques ion bar installation. Not spring tension on the header. Only the weight of the bar and springs. If the header sagged slightly you just adjust the travel distance for the door.

:roll:
 
Re: 16' Garage Door Headers

"16 pages on a door header! Wow almost up to those stairs to nowhere! :lol:"

But this thread was not nearly as interesting..... :mrgreen:
 
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