# Point Loads



## Jobsaver (Jan 28, 2011)

To what degree do the IRC prescriptive codes including span tables account for "point loads" or "concentrated loads":

On headers?

On girders?


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## GHRoberts (Jan 28, 2011)

They do not account for point loads. (But they do treat joists and rafters bearing on headers and girders as uniform loads although they are point loads.)


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## steveray (Jan 28, 2011)

Agree w/ George.....not handled in in IRC...engineering required...or whatever the BO will accept...


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## fatboy (Jan 28, 2011)

Wasn't going to post, as it may constitute performing engineering, but  I've always figured the tables were based on uniform (sorta) loads.


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## GHRoberts (Jan 28, 2011)

fatboy said:
			
		

> Wasn't going to post, as it may constitute performing engineering, but  I've always figured the tables were based on uniform (sorta) loads.


Since the tables are titled in the following manner:

TABLE R301.5 MINIMUM UNIFORMLY DISTRIBUTED LIVE LOADS

It seems tables are based on uniform loads.

---

No offense intended.


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## Uncle Bob (Jan 28, 2011)

Point loads are extremely important,

I am usually not conserned with point load unless there is a specific load; like a water heater in an attic. Then I am like poop on a stick; you ain;t going to get me off; until you provide proof positive that you have meet all load requirements.

Also, be very attentive in apartment construction; where they build a stand for water heaters to sit on; and the effect on any non-load bearing walls.

Note that the water heaters are to be included as dead loads in the IRC. See Definition of dead loads; 2006 IRC --"and fixed service equipment."

And,

R301.4 Dead Load. The actural weghts of materials and construction shall be use for determining dead load with consderation for the *dead load of fixed service equipment.*

HVAC units in attic must also be considered; however there is nothing more frightning than seeing two gas fired, 50 gallon water heaters in an attic; directly above a stairway in a two story house; without taking into account the full weight when filled with water. Especially when the water heaters (21" diameter) are centered between 24" on center ceiling joists, supported only by 5/8 OSB.

At a meeting with a major nationwide homebuilder; their engineer said; the water heaters were not considered dead loads, because when you use water; they empty and refill only when the water level in the tank gets too low.

Yes, he is still alive; and, no I did not hit him; but, I did almost lose my job. :grin:

Uncle Bob


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## GHRoberts (Jan 28, 2011)

50 gallons is about 400 pounds. About 9sqft of floor area (based on 40# live load and the 7# of actual dead load - 400/43 = 9). Even as live load not enough weight to worry about.

(My 50 gallon water heater is in a 4'x4' area above my front door. I have no concerns about it. I never even did the math to show the framing - 2x12x16' @ 16" with 1/2" plywood, is sufficient.)

It takes a lot of equipment to make an engineer concerned.

Point loads are usually of importance if they they concentrate major floor or roof loads - like at posts. Even floor joists and jack studs around openings, reasonable sized point loads, don't need to line up with studs too well.


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## Uncle Bob (Jan 28, 2011)

George,

You stated;

"It takes a lot of equipment to make an engineer concerned. "

Find an engineer; your configuration and calculations are not even close to the required support in my senario. And your weight approximations is also way off.

Uncle Bob


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## DRP (Jan 28, 2011)

We found excess capacity on a couple of spot checks of the table. I'll let you try first. Work out the loads from the table and see what shakes out. Remember the table only checks deflection of live load not total load so you'll need to run the calc both ways. Here is my calc for centered point loads;

http://www.windyhilllogworks.com/Calcs/beamclc_ctrptld.htm

This is for 2 point loads at the third points;

http://www.windyhilllogworks.com/Calcs/2ptbeam.html


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## GHRoberts (Jan 29, 2011)

Uncle Bob said:
			
		

> George,You stated;
> 
> "It takes a lot of equipment to make an engineer concerned. "
> 
> ...


Are you saying that the water heater actually fell?

The fact that it did not fall indicates that engineering would show that the load (your estimate or mine) was properly supported.


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## Yankee (Jan 29, 2011)

GHRoberts said:
			
		

> Are you saying that the water heater actually fell?The fact that it did not fall indicates that engineering would show that the load (your estimate or mine) was properly supported.


Really? Excessive bending is a structural failure. Your opinion above is one I have to fight daily . . . it doesn't have to fall down and kill someone to be considered a structural failure.


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## Mark K (Jan 29, 2011)

The beam could support the load and still not comply with the code.

Wood is interesting in that if you place a heavy load on a wood member for a long term it could eventually fail because of load duration effects.  This is recognized by the code provisions related to the design of wood members.  Such failures do occur when this issue is ignored.  Thus the fact that the member has not failed does not mean that it will not.


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## Daddy-0- (Jan 29, 2011)

Point loads are generally a bigger concern with girder trusses and large LVL beams or PSL posts. I also know that when I see a large water heater or a heavy furnace in the attic I look at the extra weight too. I think that UB raises some good points about design issues. There are lots of places to put a water heater and the attic would be my last choice for many reasons.


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## DRP (Jan 30, 2011)

I was curious. If we take George's water heater and spread it out over 2 joists each one would take 200 lbs of the load. That passes fine on his 2x12's even in the center of span. I then took the 1.33' width (16" oc) x 16' length and multiplied it x 40 psf and got about 850 lbs of uniform load on those joists as well. I wanted to check it quickly so I divided that uniform load in half and added it to the point load in the center of the joist. Remember that a point load in the center produces double the bending moment of a uniform load... long story short, it still passed handily. It sounds like the heater is towards one end of the joists, that makes a huge difference. Not many people have 2x12 ceiling joists, that also makes a huge difference.

Mark K mentioned long term creep deflection. This is part of the adjustment of base design value when you are checking a beam. For "normal" loads considered to be of 10 year duration the design value is unadjusted for duration of load. For a permanent load it is derated 10%. For short term (2 month) loads like snow the base design value can be increased 15%, For 10 minute loads like wind or seismic the increase is 1.6x base design, for impact 2x. Wood can handle large overloads of short duration well, where a constant load of much lesser magnitude will cause it to fail. The failure in long members is often excessive deflection rather than breaking.

Those king sized waterbeds on the narrow pedestal base, depending on which way the pedestal is across the joists, is it on 3 joists or 5... and that's a dynamic equipment load.


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## RJJ (Jan 30, 2011)

Drp: I kinda of agree. I not sure I understand UB point that the load is not as George stated.


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## peach (Jan 30, 2011)

even headers... we look at the jack and king studs at each window.. we need to follow that load to the foundation.

Not just because of a big failure.. if the header starts to sag (either from loads above or insufficient support from below), the drywall cracks more than it has to.. the windows don't operate correctly.. etc.  Still a failure that we can help avoid.


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## Yankee (Jan 30, 2011)

And this is the road we go down when we start codifying workmanlike construction over shoddy construction, and the difference between safety codes and building codes, and where we most often are likely to go hinky with codifying particular manufacturers specs (or not). Some on this forum feel that codes should only apply to the safety aspect, I disagree. A minimum level of workmanship should (also) be what building codes address.


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## Mark K (Jan 30, 2011)

On the issue of whether the codes should address workmanship issues you need to consider state laws.  The laws authorizing adoption of building codes typically state that they are for the purpose of promoting safety and public health and do not mention such items as workmanship.  In this context the adopted regulations cannot legaly address issues not authorized by the enabling laws.

We also need ask the question do we want to regulate everything or do we want to minimize government regulations.  In addition the more you try to regulate the more complex the codes will become and the more likely that you will find unintended consequences from the regulations.


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## Yankee (Jan 30, 2011)

Or promoting health safety and _welfare_ , , , starting to cover a good deal of ground with that.


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## DRP (Jan 31, 2011)

> even headers... we look at the jack and king studs at each window.. we need to follow that load to the foundation.


I don't see that as getting into anything fuzzy like workmanlike construction, just part of the requirement to trace the load path.


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## mtlogcabin (Jan 31, 2011)

> just part of the requirement to trace the load path.


When checking the load path on a raised floor with a rim joist how many stop at the floor plate or do you require additional reinforcment at the rim board where the point load is bearing.


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## Uncle Bob (Jan 31, 2011)

RJJ,

Ok, I'll try to make my point a little more clear;

George's water heater is sitting on 2" X 12"s spaced 16" on center(50 gallon water heater with appox. 22" width; which is more than enough support.

In the case of the homes built in Central Texas by Anonymous Homes (a major nationwide home builder); who has built thousands of homes;

In their two story homes; they placed two Rheem 50 gallon water heaters and two HVAC units in the attic space (all gas fired).

The following is a normal situation concerning their attic installation and support: 

The ceiling joists were 2" X 8" with an approximately 14' span on 24" centers.

The 50 gallon water heaters weighted 150 lbs. empty.

Fifty gallons of water weights 417 lbs. for a total weight of 567 lbs.

Not using "Engineering" but, simple math; that is approximately *168 lbs per square foot** of weight (DEAD LOAD); which in many instances, the osb carried the total weight of the water heaters.*

The water heaters were 21 3/4" wide (ceiling joists were spaced 24" on center).

23/32 (3/4") osb on 24" centers; maximum live load 100 lbs. dead load 10 lbs per sq. ft..

(be patient with the download; it's slow)

http://osbguide.tecotested.com/pdfs/en/el809.pdf

Actually, where the water heaters were supported on one side by a ceiling joist; the weight would bend the osb; and shift most of the weight to the osb.

After seeing several instances of tilting water heaters, overstressed (bending) flooring, and cracked flooring, under the weight of the water heaters; at final inspections; I started researching the problem.

With the help of some very nice Engineers on the old ICC BB; I got the information I needed.

End result: Anonymous Homes began placing the ceiling joists on 12" centers; in the area where the water heaters were installed; which solved the problem for those new homes.

However, I am not sure they went back and made any corrections to homes they had already sold.

On the old BB; I think I posted pictures of two water heaters; totally supported only on the osb; directly above the stairway, in a two story home. Should one of those water heaters go through the floor; they would fall on the stairs; blocking the exit; break flexible gas line feeding the water heater; starting a fire; and trapping the occupants in the bedrooms of the second floor.

As I stated before; in apartment complexes; please check the support under water heaters installed. I have seen many; by major contractors; where the water heaters are not sufficiently supported. Especially where the water heater is above the washing machine or clothes dryer.

Hope this helps,

Uncle Bob


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## GHRoberts (Jan 31, 2011)

According to the grading stamps I see on OSB, it will support 150#/sqft. I am not concerned about the 10%  overage (the safety factor is 2.5).

I will offer no opinion on the joists.

---

I expect the bedrooms have code required egress.


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## Forest (Jan 31, 2011)

Jobsaver,

           My two cents, IRC 301.1 "transfer of all loads from point of origin through the load- resisting elements to the foundation"  then since it not addressed in the tables for point loading IRC 301.1.3 Engineered design required.


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## Yankee (Jan 31, 2011)

GHRoberts said:
			
		

> According to the grading stamps I see on OSB, it will support 150#/sqft. I am not concerned about the 10% overage (the safety factor is 2.5).I will offer no opinion on the joists.
> 
> ---
> 
> I expect the bedrooms have code required egress.


Where is it that you see the 2.5 safety factor? (and what exactly do you mean by 2.5? 2.5%?)


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## DRP (Jan 31, 2011)

I can't speak to the safety margin for sheet goods but most building materials have a healthy safety factor. Steel is homogenous and carries 1.67:1  ultimate/allowable if I remember right. Structural lumber is very variable and has a 2.1:1 safety factor with a 95% exclusion limit. 95% of the pieces in the pack should fail at a load at least 2.1 times allowable load with 5% of pieces allowed to fail between allowable load and the 2.1x safety margin. There will be pieces that are 5-7 times stronger than the allowable load in most packs, I try to put them where they will do the most good. Often at the sawhorses I can remove the limiting defect in a stick and bump the grade up. The gradestamp is segregating volumes of lumber into groups, I can select through the group and put the individual pieces in the best places.

Don't forget that each joist on a beam is really a point load even though we call the beam uniformly loaded... Magnitude does matter but picking the exact place where uniform becomes point gets a little like some folks up the road, where does the good book say we can plow with a mule but not with a tractor.


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## Jobsaver (Feb 1, 2011)

Thanks for all of the posts. Usually, I try to participate more in the threads I start, but got busy after posting the OP.

The purpose of the thread is to try and establish better guidelines for sizing headers and girders using the IRC header and girder charts found in chapter 5, particularly R502.5(1) and R502.5(2). One desirable result from discussing this issue is to better determine what, if any, point loading specifically on headers, and girders, can be accounted for in these tables: Starting with headers, for examples:

A 32” door header supporting a point load from a ceiling beam that carries the ceiling only.

A 101” 2-ply #2 SYP 2x12 cased opening header supporting a point load from a ceiling beam that carries the ceiling only.

The same header supporting beams carrying ceiling and roof bracing loads.

And, are there specific rules of thumb that can be applied for like circumstances?

I find it curious that in the ’95 CABO, per table 602.6, MAXIMUM SPANS FOR HEADERS LOCATED OVER OPENINGS IN WALLS (feet), these spans are listed for a 2-ply 2x12:

(note reduction in spans with ’06 IRC):

*1995 CABO (602.6): #2 grade lumber with 10’ tributary floor and roof loads (italics mine)*

Supporting roof only:	_(presumably, this includes ceilings?)_		12’

One story above:						10’

Two stories above:						8’

Headers in walls not supporting floors or roofs:			16’

_(presumably, ceilings only?)_

*2006 IRC (R502.5(1)): #2 grade lumber assuming 20’ building width (italics mine)*

_Supporting roof only:	 (presumably, includes ceilings?)_		                9-9 (roof and ceiling)

_One story above:_						7-1 (w/clear span floor)

_One story above:_						8-1 (w/center bearing floor)

_Two stories above:_						5-6 (w/2 clear span floors)

_Two stories above:_						6-8 (w/2 ctr bearing floors)

_Headers in walls not supporting floors or roofs:			No listing_

_(presumably, ceilings only?)_

What accounts for the reduced spans?

Why does the IRC fail to address sizing headers for “ceiling loads only?

Most homes built in my ahj are stick-built, and commonly feature multiple pan or tray ceiling systems comprised of built-up beams, laminated beams, LVL’s and dimensional lumber. Often, beams supporting portions of the ceiling (only) will rest above a window, door, or cased opening header. At other times, the beams will carry a portion of the ceiling and a partial roof load, predominately from roof bracing. Sometimes the additional roof load will be a minor load resulting from a purlin brace. At other times, the additional roof load will be more significant, say a 1500-2000 pound load resulting from supporting the bottom end of a half-valley.

I am clumsily working a few examples using the beam calc tables listed by DRP earlier in this thread. And, as previously mentioned, am interested in determining to what extent a building inspector that depends on the tables can account for any point loads accumulating on headers, and develop safe rules of thumb.

(Later in the thread, I will address the same questions as apply to girders).

Note: The example I am working on now is for a 101” 2-ply #2 2x12 header having a point load resulting from one end of a center ceiling beam resting above the header.

20 x 20 ceiling (uninhabitable w/o storage. 10 psf  live load, 5 psf dead load – R802.4(1)).

So far, I have determined that the beam carries a tributary load of  3000 lbs, resulting in a 1500 lb. point load on the header.


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## Jobsaver (Feb 2, 2011)

Some preliminary results are indicating no problems with point loads resulting from "ceiling only" loads. Comments?


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## DRP (Feb 2, 2011)

My '93 CABO must be set up differently, sorry, I don't have a '95. Building widths in mine start at 24', headers are in 402.6- In our PM discussing reading and adjusting design values in the NDS Supplement we came up with an Fb for#2- 2x12 SYP of 975 psi. This kicks me into my table 402.6e. (This is labelled SPF...I think I'm seeing a bit of history. In the mid 90's the In Grade testing program derated 2x12's a bit and adjusted values so there may be several factors at work. Also notice the low Fv values, around '03 or so a math error at AF&PA was found from the '40's. Fv values are now about 190% of the old values...probably all more than you wanted to know right now!) Anyway, I'm not sure how much to make of the discrepencies between new and old tables without an old engineer to clarify all this....

I do believe you are on the right track mathwise though;



> Some preliminary results are indicating no problems with point loads resulting from "ceiling only" loads. Comments?


It would depend on member, span and load but for your 2-2x12's @ 101" span with 1500 lbs yes it passes easily.


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## dhengr (Feb 3, 2011)

Jobsaver:

Point loads or concentrated loads are not included in these tables, and there is no simple rule of thumb to include them.  They are more complicated to tabulate than uniform loads.  You must know some real engineering and understand the development of the beams formulas and be able to manipulate them to include or add point loads to the tabulated info.  You’re sorta asking for a Ph.D. in Structural Engineering in one forum post.  But, I’m glad you are finally considering the possibility that there might be loads on headers and girders in addition to the simple uniform loading from some tributary floor widths, which became the primary design basis of your original question about the 3 or 4 ply built-up 2x6 center line fl. girder with about 6' spans, on a 20' wide bldg.  I had this post pretty well along before I saw your post #27, so we’ll get to some of that later.

First lets talk a bit about the IRC and the two tables R502.5(1) & (2), and I’m looking at the 2006IRC also.  The IRC is set up pretty conservatively to keep you BO’s and builders out of trouble, much of the time, without needing engineering help on many of the problems you encounter, as long as you follow the IRC and understand its limitations.  It is based on the IBC and the old std. “design in accordance with acceptable engineering practice.”  This does not mean every condition you encounter can be taken care of without some engineering involvement, or that every situation is covered by a table or code section, and you must know when you need that help.  We would never set it up that way for fear that we would go hungry for lack of paying work.       The footnotes and sub headings in these types of tables are very important and every word must be read for its most restrictive meaning.  I believe these two tables basically originated a number of code generations ago, long before the ICC, IBC or IRC, the general format looks familiar, but I haven’t really dug into their exact assumptions and variables or span values for a long time.  However, let me lay down a few ground rules, or some of my thoughts about how they work and how the values were determined.  Starting at the top of table R502.5(1):

1.)   These are for girders and headers in exterior walls which will pick up half the roof load on a std. gable roof system, whether framed with rafters or metal plate connected trusses, plus some portion of the ceiling/attic load as indicated in the left column of the table.  And, while you see 20, 28 & 36' for bldg. widths, a 2' overhang is probably included.  Then they may also pick up floor loads, either center bearing (or near center bearing), which means that one half of each jst. span length goes to its exterior wall; or clear spanned which puts all the floor loading on the two exterior walls, as if using parallel chord fl. trusses.  Draw some cross sections of these different bldgs. for all five of the vert. groupings in the left column of the table, with a view toward how these various loads get to the two exterior walls.  Pick some reasonable DL’s & LL’s and tabulate them, at each level, on each wall or header, in lbs./lf of wall, and let’s talk about and check them, before you start using the beam formulas.   Also note that the snow load increases as you move to the right in the table and that the bldg. width increases moving to the right under each snow loading sub-group, increasing the wall loadings.  And, you should start to see heavier loadings and members and/or shorter spans for a given member as you move right and downward in the table.  This should answer some of your questions in post #27.

2.)   Now the second item down in the heading: they allow for four different groups of lumber, and then the all important footnote ‘b’, #2 grade lumber.  This sets the allowable stresses for our design and tabulation, or the max. span length for a simple beam; this will be primarily a bending and deflection consideration problem, but may be a horiz. shear stress issue too, for the given pieces of lumber.  But, if you look in the NDS, you’ll find that each of the groups of lumber have different allowable stresses and E’s (modulus of elasticity), so they will have used the lowest of the lumber species groups for the tabulation.  They will also have used some set of average DL’s for roofs, ceilings and floor systems, and will likely have considered some typical amount of interior walls, which can be considered a uniform loading on the girder when they are parallel to the girder.  Walls perpendicular to the girder cause concentrated loads on that girder and should usually have doubled joists under them, and are more than likely not included in these tabulations, that’s why I kept harping at you about them.  You really must know when DL’s loads and various other load conditions exceed the assumptions used in developing these tables.  And, that’s obviously not being understood, nor are those assumptions well spelled out in the tabulations, other than to say assume average DL’s.

3.)   As you move down the page and to the right, for any given size of header, you finally need more than one or two jack studs.  This is because the header reaction and thus the bearing stresses (and compression perpendicular to the grain) have gotten large enough so that 1.5" or 3" of bearing is not enough bearing length, and furthermore the jack studs acting as columns need to be larger for their assumed length and loading.

4.)   I haven’t really studied all the variables and assumptions used in developing these tables for some time now, one would have to do some calcs. on random members at various loads and spans to start to hone in on the assumptions which were used in developing these tables.  Finally, it might be easier to talk to the people who actually developed these tables for this code to really ascertain all of their assumptions and minor variations of variables.  But, the basic engineering remains unchanged from when they were first developed years ago.

The table R502.5(2) involves essentially the same thinking as above, but obviously doesn’t include roof loads, but may include ceiling/attic loads, and must assume stacked bearing walls right over the girder.  Table R502.3.1(2) for joists may be the simplest table to do some basic beam calcs. on, to get your feet wet, since it has the fewest hidden assumptions, in its development.  The stress grade, member size and span length are obvious, the DL & LL are straight forward, except for the adjustment for the jst. spacing to convert the load from #/sf to #/lf.  Then you apply the beam formulas to get moments, shears and deflections, and go to the NDS for actual stress calcs. and compare them to the allowable stresses and deflections, to determine if the member passes or fails.

DRP has given a couple bending moment equations in recent posts, M=WL/8 for a uniform load and M=PL/4 for a point load at center span and noted that if P=W, in magnitude, the bending moment and thus the stresses are doubled for the point load on a simple beam.  He also showed the beam formulas for a simple beam, uniformly loaded, post #17, in DarrenE’s thread on ‘number of jack studs,’ and I believe he started to outline some of the stress calcs. for your original girder question.  I believe his beam formula figure #1 came right out of the NDS code books, which show many different loading conditions and types of beams.  There are other places to see these same formulas.

I believe changes in these tables from one generation of the code to the next will have most to do with the poorer quality lumber we are having to use these days, and thus lower allowable stresses and E values.  There are also changes in the code requirements and various adjustment factors in the codes.  The underlying engineering, strength of materials, stress analysis, etc. has not really changed.  All of the above is what we keep calling “design in accordance with acceptable engineering practice,” picking a girder or header from these tables is not engineering, even though the tables are based on  acceptable engineering practice.  If you are going to do anything other than picking a header from the tables, after truly understanding the limitations of that table, you are starting to do some engineering and you better understand what you are doing and your own limitations.  You really must be comfortable determining DL’s & LL’s, tributary areas, types of loads, concentrated or uniform, load paths from origin of the load to the bearing soil.  And then you must be comfortable using the beam formulas and combining them as appropriate for the types of loads or spans involved, or you should probably be asking for engineering help.  Since, just as for Architects and Engineers, you should really not be practicing engineering activities beyond your experience and training level.  Thus, the admonition that if it isn’t specifically in the prescriptive code (the IRC) you should get engineering help, or have the builder get an Engineering involved.


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## Jobsaver (Feb 3, 2011)

DRP said:
			
		

> In the mid 90's the In Grade testing program derated 2x12's a bit and adjusted values so there may be several factors at work. Also notice the low Fv values, around '03 or so a math error at AF&PA was found from the '40's. Fv values are now about 190% of the old values





			
				dhengr said:
			
		

> Jobsaveroint loads or concentrated loads are not included in these tables, and there is no simple rule of thumb to include them.
> 
> One would have to do some calcs. on random members at various loads and spans to start to hone in on the assumptions which were used in developing these tables. and go to the NDS for actual stress calcs. and compare them to the allowable stresses and deflections, to determine if the member passes or fails.
> 
> I believe changes in these tables from one generation of the code to the next will have most to do with the poorer quality lumber we are having to use these days, and thus lower allowable stresses and E values.  There are also changes in the code requirements and various adjustment factors in the codes.  The underlying engineering, strength of materials, stress analysis, etc. has not really changed.


This helps me to understand some of the differences between the older and newer codes. I had imagined that some of the difference also occured because during the compilation process to create the ICC codes, at every turn the most conservative information was chosen. It does not stand to reason that the panels of experts performing the compilations did their own math to re-establish span tables, including each span in relation to each footnote selected.

Why is there no distinction for headers bearing "ceiling loads only"? In my eyes, it is a flaw in the compilation resulting in grossly conservative, even missing, information.

Of course "rules of thumb" can be established to determine to what extent the maximum spans for headers listed can accept "ceiling loads only", point or otherwise.

I submit this equation: think of it as a test question on a exam:

Prove the following:

For any interior header selected out of table R502.5(2), for a typical single story home, under what circumstance will the header fail given the following conditions?:

The interior header is supporting ceiling loads only for no more than two rooms having a combined gross ceiling area of 700 sq. ft.

There exists no more than one concentrated load on the header resulting from a ceiling beam.

I am exploring this question, which includes performing a number of calcualtions using the maximum spans given in table R502.5(2), to ascertain whether or not typical loading confiqurations found in my ahj are overloading table sized headers, despite certain point loads.

Remember:

Most homes built in my ahj are stick-built, and commonly feature multiple pan or tray ceiling systems comprised of built-up beams, laminated beams, LVL’s and dimensional lumber. Often, beams supporting portions of the ceiling (only) will rest above a window, door, or cased opening header.

The simple answer is, no. Or, you must hire an engineer whenever a supporting pan or tray ceiling beam rests over a header.

These are both inadequate answers that reflect an ideal that is not my reality.


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## peach (Feb 11, 2011)

I follow point loads from roof to floor to headers to foundation.. if it's wrong.. they fail..   if it's new construction, it really sucks to be them..


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## Daddy-0- (Feb 11, 2011)

> When checking the load path on a raised floor with a rim joist how many stop at the floor plate or do you require additional reinforcment at the rim board where the point load is bearing.


I make them post the load all the way to the foundation with solid dimensional blocking beside the rim board. Otherwise, you have defeated the purpose.


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## DRP (Feb 12, 2011)

> When checking the load path on a raised floor with a rim joist how many stop at the floor plate or do you require additional reinforcment at the rim board where the point load is bearing.





> I make them post the load all the way to the foundation with solid dimensional blocking beside the rim board. Otherwise, you have defeated the purpose.


At what point? Under every door jack or under significant loads? I think it would depend on the magnitude of the load and the compressive strength of the rim. Aside, most of the engineered rimboard has higher compressive strength than sawn lumber.


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