Loose roof plywood decking and gang nail plates 4

[SpiderM]

I have an apartment complex that was damaged by a wind storm event. Several trusses were broken and the gang nail plates were pried loose, to varying degrees, from the truss members. The top chords are twisted or rolled which pulled or pried the gang nail plates loose, at this point I assume due to racking of the roof diaphragm. Lastly, the plywood now has a gap between the top chords of the trusses.

My questions...

Because of the varying amounts of prying, how much of the gang nail plate must be in full contact with the wood member? I know the easy answer is 100%, but is there a safety factor or something similar.

The twisted or rolled top chords have created a gap between the plywood deck and the top chord. How tightly does the plywood decking need to be attached to chord? Again the easy 100% number, but what are the limitations.

Lastly, because this is an apartment complex, it was most likely design under a prescriptive method of framing. An analysis of the roof diaphragm could determine how much of the roof plywood is required for the diaphragm, but the major unknown is the nailing size and spacing. Do the IRC currently require that the entire roof be the diaphragm? Or are there variations of the roof.

Basically, the proposed solution is to patch all the damage, but my concern is to insure that the capacity of the building can be confirmed.

I may need to elaborate if the conversation deviates from the course.
I can attach photos if anyone would like.

 

[dik]

Thanks Ron... couldn't have said it better.

Dik

 

[SAIL3]

Ron, you hit the nail on the head in this one..so to speak.

 

[BAretired]

Ron,

What a sad commentary on our profession...and on insurance companies. I can honestly say that this has not been my experience but working for insurers has been a minor part of my practice.

In the present case, Engineer B should remember that the building has already been damaged by a wind storm, so I'm not sure how much comfort he can take in "the likelihood of the roof ever seeing the design loads is very low".

Whether SpiderM is retained by the owner or the insurer, he must base his opinion upon honest conviction and shall hold paramount the health, safety and welfare of the public. The red print is an excerpt from the APEGGA Code of Ethics.

The OP cannot be responsible for opinions expressed by others but if he believes that such opinions are being "taken to the bank" and thereby creating an unsafe condition, he is duty bound to report such malpractice to his professional association. At least that is the way I read our Code of Ethics.

BA

 

[dik]

The engineer for the insurance company only does a report; he is not responsible for the new framing (generally). I've always insisted that engineering is the 'oldest profession'.

Dik

 

[BAretired]

dik,

If the engineer for the insurance company states to his client that the roof can be repaired, the owner still needs to find an engineer willing to take responsibility for the framing. If he can't find one, the issue is not resolved.

BA

 

[SpiderM]

I cannot adequately express the level of appreciation I have for everyone and their comments.
Ron – Your commentary was dead on; I know you fully understand the situation.
BAretired – I have that exact quote in my preliminary report. As I tell all my clients, I will report the facts as I see them. “If it is a benefit to you, great; if not, sorry but that’s how I see it.” And of course, this motto, per say, has begun to overload my production capacity from public adjusters, attorneys and, yes, insurance companies. I never intended to become an expert witness, but I love solving puzzles.
I have requested the calculations supporting their repairs, so I will need to see what happens next. I wonder if it is possible to require that the other engineers provide the repairs or co-sign a third engineer’s final repair design.

 

[dik]

BA:
It is as far as the insurance company is concerned... the next step is up to the home owner.

Dik

 

[BAretired]

dik,

Then the company is not providing insurance. The owner should sue. Only problem is he probably can't afford to pay a lawyer.

BA

 

[Ron]

BA...you're right. Most homeowners don't know the difference and can't afford to push it. I've recently seen some of the personal injury attorneys advertise that they will take on insurance companies for non-payment on a contingency basis, just as they do for personal injury. One of them just recently created a construction law group to do exactly what we're discussing here.

 

[BAretired]

Ron,

Maybe that is something to be encouraged. And, in addition, maybe we should challenge those engineers who sell their profession short, those who pander to companies who concern themselves only with the bottom line. If we don't do it, nobody else will. If we don't do it, the public will suffer.

BA

 

[Ron]

BA...agreed. We are part of the problem. In a "self-policing" profession, we usually fail to do so.

 

[dik]

I have a 'canned' paragraph that I include in my insurance reports that states the I've informed the homeowner that even though I'm employed by the insurance company my report would essentially be the same as if I was working for the homeowner and that he can seek another engineering opinion. I also state that I cannot provide him a copy of this, and that he would have to obtain a copy of it from the insurance company (sort of my own Miranda...).

I also have a paragraph for photographs that states that I have taken the photos, downloaded them to my own computer and made CD copies of these without alteration and that the CD's include all photographs, including those out of focus or under or overexposed. I sign and date a couple of copies and file them. I note in my report that all photographs are part of the report, but that only a few have been included, and that those not included are available on request. I take too many pix... (memory joggers).

Dik

 

[a2mfk]

This thread took an odd twist, but I like it.

To address the specific case at hand, Spider, you are absolutely doing the right thing and stick to your guns. I have been involved in this type of work for several years now, and have seen these things play out. Call it exactly like you see it, and build your case strongly using code and other references. Let the other side do what they are going to do. No need to call them out as "bad engineers" because they don't agree with you or they think a repair is adequate, unless you see something that meets the definition of negligence, just come up with your own set of repairs and opinions.

With this much money on the line, there will be litigation, and a compromise will be made in the middle. Laypeople are going to make the final decision (attorneys, mediator, maybe a jury), and there is nothing you can do but lay out all the facts as you see them very clearly. Then let the cards fall.


I can only say I have been heavily involved in this industry for several years now, and many times our best engineering opinion and judgment seems thrown out the window because of LITIGATION. Facts get cloudy, some engineers seem to custom tailor their opinions for their clients, and lay people aren't educated enough in this field to sort out the details.

I do not however accept the broad-based indictment of forensic engineers who work for one company or another based on who signs their check as being unethical. There are a few bad apples out there that clearly do so, and I have seen many letters and reports by homeowner's engineers that were just plain awful.

Much like Spider said, my opinion never is skewed because of who hired me, its my opinion, take it or leave it. Most engineers I know who do a lot of work for insurance companies have this exact approach.

I'd love to talk more about this subject but because of legal discovery its probably not wise.

 

[Ron]

a2mfk...agree. I practice in this arena every day. I cannot afford to have my reputation compromised by skewing data or opinions based on who pays the bill.

 

[BAretired]

Excellent contributions, gents.

BA

 

[dik]

and good questions, BA...

Dik

 

[a2mfk]

I am sure you do Ron, love to swap war stories sometime over a beer...

 

[Ron]

a2...anytime!

 

[msquared48]

Unfortunately, but it is a fact of life, in the higher damage situations, it is more profitable for the insurance company to reject the professional opinions of structural engineers and demand a cheaper fix, accepting the fact that the problem will wind up in court. In some instances, it is cheaper for the insurance company to pay for the attorney than pay the fix recommended by the structural engineer.

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[dik]

You may want to enlist the services of the local building department by making them a party to the adequacy of the repairs.

Dik