16' Garage Door Headers

[kilitact]

Re: 16' Garage Door Headers

Heaven wrote:

And guess what, we don't inspect all the work, either! We inspect a representative portion of the work. Does your department do 100% inspections also?

We don't do "drive by's, for inspections or plans review. If we sign our name, we've reviewed and/or inspected, won't want it any other way.

rick a wrote:

The question is the degree you take on yourself.

Heaven wrote:

If so, I am truly impressed that your jurisdiction has the budget to fund your position

And here I thought thats why we collect fire, life safety and structural plan review fees.

What does your jurisdiction cite has justification for collecting these fees??

I respect your due diligence. The question is the degree you take on yourself.[/quote:3thbssr7]

I thought has a code official our job was to review and inspect. Perhaps not in your area??

 

[Heaven]

Re: 16' Garage Door Headers

You just can't help yourself , can you.

You have characterized my comment of "partial inspections" as "drive-bys" on top of characterizing plan reviews other than your own as "the braille method".

 

[RickAstoria]

Re: 16' Garage Door Headers

rick a wrote:

I respect your due diligence. The question is the degree you take on yourself.

I thought has a code official our job was to review and inspect. Perhaps not in your area??

Sure. I'm not asking you to not review and inspect but you simply are not qualified to perform the calcs if you don't know squat about A) how to do perform the math, B) Understand the science behind the math and if you don't understand A) & B) then C) you don't know what would be adequate or not-adequate in terms of design and the engineering calcs. So you'll totally F--- up. If you don't know engineering to any degree, how can you know what is adequate engineering and inadequate engineering. If you don't know engineering to any degree then you simply will not understand the calculation and math. You wouldn't know what it is adequate engineering from your butt-hole. Get it? Learn some engineering or leave it to the engineers & architects to review the engineering calcs and let them report their finding to you. You see, architects actually do have to learn a little bit of engineering in just about any NAAB accredited degree programs.

What gives you the credential to review the calcs. What measures have you taken to learn engineering?

 

[brudgers]

Re: 16' Garage Door Headers

I think the answer is in the 1995 CABO and needs to be put into the IRC. Someone check CABO section 602.6 and table 602.6. I believe it is a double 2x12 for a 16 foot opening. As has been pointed out in other posts, there may be other factors but the double 2x12 works prescriptively if every other portion of the code is being complied with. Most garage door openings around here would require a DP to sign off on them though because they do not meet the prescriptive path listed in IRC 2006.

No, a double 2X12 does not work for a 16' opening if the roof is bearing on it.

And requiring a design professional to read a load table is, in my opinion, asinine.

 

[RickAstoria]

Re: 16' Garage Door Headers

I think the answer is in the 1995 CABO and needs to be put into the IRC. Someone check CABO section 602.6 and table 602.6. I believe it is a double 2x12 for a 16 foot opening. As has been pointed out in other posts, there may be other factors but the double 2x12 works prescriptively if every other portion of the code is being complied with. Most garage door openings around here would require a DP to sign off on them though because they do not meet the prescriptive path listed in IRC 2006.

No, a double 2X12 does not work for a 16' opening if the roof is bearing on it.

And requiring a design professional to read a load table is, in my opinion, asinine.

What would the total load be on the beam. The roof load would be transmitted the beam and that is all it would be carrying except maybe studs between the beam and the roof.

If it is a gable roof - it may or may not have much of a roof load at all. If it is hip roof then it would have a larger tributary area. If it is a gable roof, it depends on the gable roof orientation. It may only have the tributary area of one single roof rafter (ie. 1' to 2' by 16' - or 16' to 32' tributary area). It depends on the tributary area load on the beam header.

At minimum condition, it may work but I would want the beam to be at least as thick as the stud wall bearing it. So if the wall is a 2x6 wall framing then 6" x 12" beam would spec'd. If the wall is a 2x4 frame then 2 ply 2x12 with a 1/2" plywood piece.

 

[rktect 1]

Re: 16' Garage Door Headers

I think the answer is in the 1995 CABO and needs to be put into the IRC. Someone check CABO section 602.6 and table 602.6. I believe it is a double 2x12 for a 16 foot opening. As has been pointed out in other posts, there may be other factors but the double 2x12 works prescriptively if every other portion of the code is being complied with. Most garage door openings around here would require a DP to sign off on them though because they do not meet the prescriptive path listed in IRC 2006.

No, a double 2X12 does not work for a 16' opening if the roof is bearing on it.

And requiring a design professional to read a load table is, in my opinion, asinine.

I thought we were under the assumption that this opening was in a non load bearing, gable ended wall.

I am a bit confused though by your last statement. Do you, as a DP, not look at load and span tables? Or do you feel it is just beneath you to do so?

 

[kilitact]

Re: 16' Garage Door Headers

rick a wrote;

What gives you the credential to review the calcs. What measures have you taken to learn engineering?

At a minimum, what the State of Oregon requires now and before they accepted ICC certification without any other experience.

 

[brudgers]

Re: 16' Garage Door Headers

I thought we were under the assumption that this opening was in a non load bearing, gable ended wall.

That makes sense.

I am a bit confused though by your last statement. Do you, as a DP, not look at load and span tables? Or do you feel it is just beneath you to do so?

No.

My point is that requiring a design professional to size a typical residential garage door header is asinine.

Any reasonably intelligent person ought to be able to do so safely with modest effort and a wee bit of diligence.

And if a building official, inspector, or plans examiner cannot verify it's adequacy, they should not be in their position.

 

[vegas paul]

Re: 16' Garage Door Headers

brudgers - I agree with your reference to effort and diligence, but the original question was, "Can it be done prescriptively from the IRC?" What span table would you apply the effort and diligence to?

Another way of asking this is, "What size beam is sufficient for a 16' gable opening, and what table/section of the IRC did you find it in?"

 

[mtlogcabin]

Re: 16' Garage Door Headers

VP there is not a header chart in the IRC or IBC which will allow a span of more than 14 ft 1 inch. You have to go somewhere else.

 

[RickAstoria]

Re: 16' Garage Door Headers

rick a wrote;

What gives you the credential to review the calcs. What measures have you taken to learn engineering?

At a minimum, what the State of Oregon requires now and before they accepted ICC certification without any other experience.

If it was the minimum, it doesn't say a whole lot in the area that matters - understanding engineering sciences and the associated math.

It doesn't say alot. You are good at reading the code book. Whoo Hoo!

Now, it is the other education that you taken that matters.

 

[RickAstoria]

Re: 16' Garage Door Headers

brudgers - I agree with your reference to effort and diligence, but the original question was, "Can it be done prescriptively from the IRC?" What span table would you apply the effort and diligence to?Another way of asking this is, "What size beam is sufficient for a 16' gable opening, and what table/section of the IRC did you find it in?"

Very simple... statististical plot theory of interpolation would give a reasonable answer.

A better thing is buy a book on basic engineering like:

"Structural Engineering for Architects" by Kenneth Lauer

or download some of the ones in PDF format from the late 1800s and early 1900s as the equations are still the same and size it to the current code required loads. The math and engineering formulas hasn't changed in regards to simple beam loads in all this time.

LEARN, STUDY and UNDERSTAND what you are reading. PS: The equation is in the book.

If a person is intelligent and dilligent AND prudent - he/she would do one of the prudent paths - hire a qualified professional or learn how to do it competently before performing the work. There is always two prudent paths. Of course, if the person has already learned how to do it competently, the person would be able to perform the task.

 

[vegas paul]

Re: 16' Garage Door Headers

Rick & mtlogcabin - you're missing the point of my original question (and after 6 pages, the subject has drifted!)

I KNOW that the span tables in the IRC only go to 14'1". I also know that you CAN'T interpolate beyond the range of table values, only within that range. Extrapolation is not allowed. I also know that you CAN do the load calcs from info in books you mentioned... BUT my question was for the average applicant/homeowner that has been told that the IRC is a prescriptive path towards designing a simple structure - and that's what he wants to do. My engineering degree gets me where I want to go... but the applicant is initially being told (by ICC and many jurisdictions) that the answers are in the book. I don't see a simple one-story detached garage with a double door as being too far "outside the box" for IRC design, and I feel the code should be amended.

Telling a homeowner to apply more effort and be more diligent is not the type of customer service I am aiming for. But designing his beam from non-adopted (but reputable) references is also not my goal.

 

[peach]

Re: 16' Garage Door Headers

The IRC allows for individual members to be engineered (that's why we can accept trusses.. plain old 2x4's can't span that far)... and we don't require the entire structure to be engineered... LVLs are no different.. it's an engineered component.. (just make sure you get the manufacturers layout for your files).

God, I'm glad I didn't read the whole thread!

R301 .. engineered design

 

[Uncle Bob]

Re: 16' Garage Door Headers

Paul,

"but the applicant is initially being told (by ICC and many jurisdictions) that the answers are in the book."

That's the first problem; because the IRC is not a how to book; it only reflects the minimum requirements; and allowance for using engineered wood products like LVLs to accomodate longer spans than are in the IRC tables.

If they want a two car single-door garage; they are going to have to have a wall that is at least 18' 8" to accomodate the narrow wall requirement of 16" inch minimum and the 16' opening. In this case they are simply going to have to use an engineered beam.

I've seen too many swayback garage opening where the beam couldn't support the load (usually load bearing walls).

"I don't see a simple one-story detached garage with a double door as being too far "outside the box" for IRC design, and I feel the code should be amended."

Are you thinking that; if the wall opening is in a non-load bearing exterior wall; that perhaps something like double 2" X 12"s would work? (Roof and Ceiling not being supported by that wall?) And, that something like that should be the amended code change?

Or did I just fall off the turnip truck into a pile of horse manure?

Uncle Bob

 

[vegas paul]

Re: 16' Garage Door Headers

Nope, UB, you were probably driving the Turnip Truck, if I'm any judge of character! I was just suggesting that the tables could be expanded to span 16' since it is such a common span for a common use. Whatever the beam size - or combination of beams, necessary. I don't want sway-back garages either, but doubling/tripling/quadrupling dimensional lumber is used elsewhere in the IRC, so I simply would like to be used for this common problem. I guess I can keep wishing... !!!

 

[mtlogcabin]

Re: 16' Garage Door Headers

I was just suggesting that the tables could be expanded to span 16' since it is such a common span for a common use.

We had a local engineer do just that (16' and 18') based on our local loads

 

[kilitact]

Re: 16' Garage Door Headers

Rick A wrote:

You are good at reading the code book. Whoo Hoo!

Thank you, for the kudos. I find that being able to read and comprehend what one is reading is essential to this line of work. Even for a non-professional designer, I would think it to be important for you to develop your reading and comprehensive skills.

 

[brudgers]

Re: 16' Garage Door Headers

brudgers - I agree with your reference to effort and diligence, but the original question was, "Can it be done prescriptively from the IRC?" What span table would you apply the effort and diligence to?Another way of asking this is, "What size beam is sufficient for a 16' gable opening, and what table/section of the IRC did you find it in?"

R301.1.3

It says "in conformance with accepted engineering practice," not "by a PE."

Looking at span tables for a simple case is both "accepted engineering practice" and something which need not require a PE.

It's also something that any person responsible for reviewing plans or inspecting construction ought to be able to recognize or verify.

 

[brudgers]

Re: 16' Garage Door Headers

BUT my question was for the average applicant/homeowner that has been told that the IRC is a prescriptive path towards designing a simple structure - and that's what he wants to do. My engineering degree gets me where I want to go... but the applicant is initially being told (by ICC and many jurisdictions) that the answers are in the book. I don't see a simple one-story detached garage with a double door as being too far "outside the box" for IRC design, and I feel the code should be amended.

R301.1.3 covers the issue.

The code doesn't need amendment.

It's already got to much prescription.

And too little common sense.

 

[peach]

Re: 16' Garage Door Headers

can't expand the tables to include lumber than won't span that far.. we don't see old growth lumber anymore.. a header is not like a girder than you can just keep adding width to... the wall is only going to be a 2x4 or 2x6

it's an engineered product.. and you get their specs.

 

[brudgers]

Re: 16' Garage Door Headers

The header table lumps all species together.

It doesn't include SS, No. 1 grade, or machine rated lumber.

It also requires a Ground Snow Load of 30 PSF...that's more than they see in southern Iowa, all of Ohio, and just about everywhere west of the Dakota's per 301.2(5).

And yet there's six friggin' pages of light guage metal stud header tables.

 

[RickAstoria]

Re: 16' Garage Door Headers

The IRC allows for individual members to be engineered (that's why we can accept trusses.. plain old 2x4's can't span that far)... and we don't require the entire structure to be engineered... LVLs are no different.. it's an engineered component.. (just make sure you get the manufacturers layout for your files).God, I'm glad I didn't read the whole thread!

R301 .. engineered design

The answer is IN the book but in an indirect way. It tells you where to look and what code or engineering standards to use and so on. It would lead on to various resources.

A 16-ft wide garage door is not a prescriptive thing. It isn't even a standard garage door and why would a person with an automobile need a 16-wide door. That is why they make two 10-wide doors with a little space between the doors.

Prescriptive method is only good for average home-owner vehicles and occupancy uses not odd or unusual uses. Those are not the norm. If it does not follow the normal suburban lifestyle then it is not going to be entirely prescriptive. You just have to engineer the component. If the home-owner can not engineer the component because they lack the skill then they should hire a professional who can to do that.

In Oregon, it can be anyone if it is an exempt building but the documents would need to be resubmitted with calcs performed to accepted standards. This will likely be an engineer because a building designer would not be doing a component only deal as that can get messy in legal matters.

 

[RickAstoria]

Re: 16' Garage Door Headers

Rick A wrote:

You are good at reading the code book. Whoo Hoo!

Thank you, for the kudos. I find that being able to read and comprehend what one is reading is essential to this line of work. Even for a non-professional designer, I would think it to be important for you to develop your reading and comprehensive skills.

Sure, I know and have read what you have wrote.

However, you haven't entirely answered the question I asked. What did you do to achieve the knowledge necessary to calculate advance structural calculations and understand the calculations. How do you know if the beam is sufficient if you don't know anything about engineering sciences and the calculations involved. Do you know how to read the equations and math involved. Do you understand what you are looking at when looking at such calcs. How did you get that knowledge?

Identify that.