Originally Posted By: mcyr This post was automatically imported from our archived forum.
Curtis; According to the IRC, the tables listed is L/360 which would be the minimum deflection allowed.
On my Commercial jobs, they are usually designed for L/460 and higher.
Check the copyright of your reference. I have a framing book given to me by my father with a copy rite of 1914. I just keep it for sentimental reasons now, ha. ha.
Originally Posted By: mboyett This post was automatically imported from our archived forum.
I think Larry is exactly right. When I asked the masons working on one of the homes if he “habla ingles?” he said “a leetle”. There were no drawings nearby and the picture I did get of the detail was at the sales office as all of the construction foremen were at a weekly meeting at the main office somewhere else. The mason’s were winging it I suspect and would have the lintel covered up with stone before a foreman ever had a chance to review their work.
Originally Posted By: bking This post was automatically imported from our archived forum.
Another thing to look at on new construction: If you have LVL’s that are 16, 18 inches tall or larger they obviously are holding up a lot of weight.
Two 2x4’s under each end is not enough ! three 2x4s minimum and sometimes 4 or 5 are needed. If 2x6’s are used then 2 is usually ok or sometimes 3 needed. This depends on whether or not other loads are on that beam such as another beam connected at a T joint, 2nd floor loads as opposed to just ceiling loads and roof loads on them.
A lot of framers think two 2x4's is the rule, well it is with sawn lumber beams but not LVL or steel beams. Don't go looking in the code books, its manufactures info and architect info that goes into engineered lumber applications. Code has not gotten there yet.
Originally Posted By: mcyr This post was automatically imported from our archived forum.
It appears that if the 6"x 4" angle was installed at the garage door with the 6" leg placed horizontal, that the deflection caused by the weight could some what make it look like it were sagging.
Was the positioning of the lintel verified?
Originally Posted By: mboyett This post was automatically imported from our archived forum.
No, it was not verified on the home I inspected. The 6" leg was being installed vertically on the house where I was able to get the photos of the lintel before it was installed though. i.e the last two photos.
Bruce, interesting input on the number of jack studs needed. I'll have to read up on LVL literature more to have a reference.
Originally Posted By: roconnor This post was automatically imported from our archived forum.
portion of the load (weight of furniture, people, etc.), and does not include Dead Load (weight of materials). It is only a limitation for calculating/sizing structural members, and doesn’t help in assessing an installed member that will have both Dead Load and Live Load.
A general rule of thumb for residential construction (and a requirement for commercial construction under the IBC) is that the deflection under the Total Load (Dead Load + Live Load) for floor framing members should not exceed L/240 or 1" in 20'
JMO and 2-nickels ... 
-- Robert O'Connor, PE
Eagle Engineering ?
Eagle Eye Inspections ?
NACHI Education Committee
I am absolutely amazed sometimes by how much thought goes into doing things wrong
Originally Posted By: roconnor This post was automatically imported from our archived forum.
mcyr wrote:
I think I will stick with the L/360 as acceptable value.
To each his own as to the guidelines used for a home inspection. Just make sure you can back up that flag at L/360 for Total Load as it's not part of any industry standards, and pretty restrictive for residential construction (unless it's an unoccupied home with very little loading the floors).
I generally use the L/240 model/local code requirement for installed/total load (or 1" in 20' ... which is noticeable on a "visual" inspection), up to about a 3/4" maximum deflection in finished areas as that becomes very noticeable. But there is no back-up for that 3/4" maximum ... just my personal professional opinion wearing my SE hat as a reasonable maximum deflection for residential construction regardless of the span.
Also talk to some local SE's too as to what they think as they will be doing the follow up on the flag in the report.
JMO and 2-nickels ... 
-- Robert O'Connor, PE
Eagle Engineering ?
Eagle Eye Inspections ?
NACHI Education Committee
I am absolutely amazed sometimes by how much thought goes into doing things wrong
Originally Posted By: mcyr This post was automatically imported from our archived forum.
Robert,
This morning I looked into just that as to what the structural Engineer had designed for the floor system of the building I am building right now.
The TJI's were designed for L/360, and the depth of them was 11/7/8" with a 14 to 16 foot span and designed for total load of dead and live load.
Wether this applies to residential or not, I guess I would not know. I do not do residential any more.
I am into the L/360 and L480 on most of the projects I do.
Increasing the depth of the floor joist will help in reducing the deflection.
Spacing center to center will also help in the deflection without increasing depth.
There are a variety of ways to overcome this 1" in 20' allowable from your book, it is not acceptable in mine. If my floor would sag 1" in 20 feet, I would have a problem with that.
If I read the IRC correctly, floor joist spans for common lumber species (residential living areas, live load =40 psf L/360, bedroom areas, I would agree on the L240.
I guess at all this, I am saying that if I place a marble or a ball on a hardwood floor, I do not want it to roll ten feet.
Hey, so far I haven't used any books. ha. ha.
I lied, I used the IRC only for a peak. Memory is slowing down.
Originally Posted By: Michael D Thomas This post was automatically imported from our archived forum.
A few of the things I?d be asking myself are:
1) If this was built per plans, what is the designed maximum deflection?
2) Are other similar complete structures in the same development displaying that 7/8? deflection?
3) In the garage under construction, as also noted by someone else above, the lags certainly don't look like they are 16" on center. Will additional fasteners be installed?
4) Were "1/2 bolts", or 1/2 *lag* bolts specified?
5) If bolts are indeed what are specified, what grade? (If that?s actually an engineered member, not just a guess, this should be specified).
6) The drawings specify masonry units, not stone, and some of the other details appear different to me. Where the plans ?recycled? for use in current project? If so, what was the approval process for the changes? Builder reuse of designs with structural modifications un-reviewed by architects or engineers is a common cause of serious ?design? related construction defects.
7) What?s the flashing detail at that angle iron? What happens when water gets in behind the stone?
8) How is that stone attached to the underlying structure?
A lot of these questions are beyond the scope of a visual inspection of a complete structure, but they are all things I woud keep in mind in determining how concerned to be about observations such as the observed deflection.
Originally Posted By: mboyett This post was automatically imported from our archived forum.
Correct me if I’m wrong, but I think Marcel, while wearing his contractor’s hat, is saying that he holds himself to a higher standard & tighter tolerance while constructing such beams. Robert & Curtis are looking at it from a SE/PE perspective and saying codes and other guidelines don’t require that level of tolerance. Seems to me that both are correct.
Michael T...I know your questions and comments are rhetorical but I will try to comment on them in a couple of hours. I've got some errands that need to be run right now.
Originally Posted By: mboyett This post was automatically imported from our archived forum.
Michael D Thomas wrote:
A few of the things I?d be asking myself are:
1) If this was built per plans, what is the designed maximum deflection?
I did not see that specification on the set of drawings that I saw. It might have been there, I was just looking for the header details though.
2) Are other similar complete structures in the same development displaying that 7/8? deflection? No, I looked at 2-3 other homes and did not see that deflection.
3) In the garage under construction, as also noted by someone else above, the lags certainly don't look like they are 16" on center. Will additional fasteners be installed? I doubt it. Without having the specifics I suspect the mason was installing the lags on 32" or maybe even 48" centers.
4) Were "1/2 bolts", or 1/2 *lag* bolts specified? The drawing appears to spec 1/2" bolts only.
5) If bolts are indeed what are specified, what grade? (If that?s actually an engineered member, not just a guess, this should be specified). Don't know
6) The drawings specify masonry units, not stone, and some of the other details appear different to me. Where the plans ?recycled? for use in current project? If so, what was the approval process for the changes? Builder reuse of designs with structural modifications un-reviewed by architects or engineers is a common cause of serious ?design? related construction defects. Yes, I suspect the details were 'recycled' from another project and shared by many of the home plans for that area. I do not know what the nationally known builder's approval process is.
7) What?s the flashing detail at that angle iron? What happens when water gets in behind the stone? Don't know
8) How is that stone attached to the underlying structure? Don't know
A lot of these questions are beyond the scope of a visual inspection of a complete structure, but they are all things I woud keep in mind in determining how concerned to be about observations such as the observed deflection. I agree and thanks for the comments & questions.
Originally Posted By: roconnor This post was automatically imported from our archived forum.
mboyett wrote:
Correct me if I'm wrong, but I think Marcel, while wearing his contractor's hat, is saying that he holds himself to a higher standard & tighter tolerance while constructing such beams. Robert & Curtis are looking at it from a SE/PE perspective and saying codes and other guidelines don't require that level of tolerance. Seems to me that both are correct. 
I think you hit the nail right on the head. Marcel may build to higher than minimum standards, which is good practice. In fact when I am designing a building I typically exceed the minimum standards. However, when you are inspecting/evaluating an existing installation it gets sticky, and can be correctly argued that there is no requirement to exceed the minimum standards ... been there, done that ...
I usually tell my HI students not to get caught up in sometimes confusing design/code provisions (although they are very useful as a "guide" if correctly applied), or to try and "evaluate" a problem which is beyond a home inspection. Look directly down the bottom of members if possible, look for cracking near the middle of ceilings, and put a big kids marble on the floor above to check things out on a "visual" inspection. If you can see noticeable sag in the members (3/4" in 20' is barely noticeable), or the marble immediately rolls to the center (or edge ... but thats another issue) then there may be a problem.
Even if you do measure deflections, I generally don't recommend reporting hard numbers which can get sticky. Just try to keep things general, and follow the rule of "Observe and Report" ... something along the lines of ...
Quote:
The framing above the overhead garage door appeared to have a significant sag in the middle. This may be a sign of an undersized or incorrectly constructed beam above the opening. The beam and components were not completely visible, and the evaluation of sagging structural members is beyond the scope of a home inspection. It is (strongly) recommended that the framing in the area of the overhead garage door be evaluated by a licensed Structural Engineer to determine if there is a problem.
JMO and 2-nickels ...
-- Robert O'Connor, PE
Eagle Engineering ?
Eagle Eye Inspections ?
NACHI Education Committee
I am absolutely amazed sometimes by how much thought goes into doing things wrong
Originally Posted By: roconnor This post was automatically imported from our archived forum.
P.S. Also keep your eyes open and look for things that just don’t look right, or rub you the wrong way. An initial gut feeling that something is wrong for an experienced inspector is usually on the money (but not always … )
I did one inspection where there was a brand new ceiling in only one area of the house, which rubbed me the wrong way. So I crawled up into the tight attic (normally would have reported it as not completely accessible) and noticed a problem. The low slope roof rafters were undersized in that area of the house, so they just posted them down to the ceiling joists in the middle. Solved the probable roof sagging, but overloaded the ceiling joists. The owner indicated he had to keep patching the ceiling in that area (probably after each winter), so he finally replaced the sheetrock ...
JMO and 2-nickels ... 
-- Robert O'Connor, PE
Eagle Engineering ?
Eagle Eye Inspections ?
NACHI Education Committee
I am absolutely amazed sometimes by how much thought goes into doing things wrong
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