Problem, Dilemma and Solution??

[jheidt2543]

Problem, Dilemma and Solution?

The Problem:

I was asked to investigate an existing light manufacturing building built in 1965. There have been two additions to the original building since 1965, one on a sidewall and one at an endwall. The additions resulted in reduced wind load on one sidewall and additional snow loading along an endwall due to drifting from the higher addition. The cause for concern was some distortion of the main frame members and deflection of some of the columns. The structure is a metal building 200’ wide x 125’ long with a 14’ eave height. The original design/build drawings were found, as well as the original structural calculations by the metal building manufacturer (this was a real surprise!). A note on the design/build drawings says in part, "...Omission of knee braces & cross bracing is based on the theory of diaphragm action of a building completely covered inside and outside with 26 ga. metal panels and is to be supported by engineering calculations of the manufacturer". The manufacturer’s structural calculations included diaphragm action calculations as well as restrictions on their use, some of which have been violated.

Upon finding the distortions and deflections after a large snowstorm last winter (2002), the Owner braced some of the framing and removed a large rooftop unit over the affected area. However, the snowstorm was not even close to the nearly record snowfall of 1979 that the building survived.

My investigation confirmed that the X-bracing and knee bracing where left out, which is my immediate concern. The roof and walls both have interior and exterior panels that are in fairly good condition for the diaphragm action. I also suspected, after looking over the original calculations, that the building would not meet current building code requirements; particularly since adoption of the IBC 2000 Code by the local building department. To confirm my suspicions, I sent all the information to the original building manufacturer’s engineering department for review. I asked them to look at the building structure using the original loadings and the new loadings required by the IBC 2000 Code. They agreed that the X-bracing and knee braces should be installed ASAP, as well as reinforcing the roof by adding additional new purlins in the snow drift areas.

The Dilemma:

The Owner is balking at making the recommended changes, which admittedly, will be very expensive. My dilemma is what to do now that I know the building is unsafe in its present condition. As I see it there are three courses of action:

1. Ignore the problem and hope for the best, after all, the building has survived this long without modification. I’ve been paid for my work, now it is up to the Owner. (?)

2. Agree to the partial correction of adding the X-bracing and knee bracing, but not the purlins, which would be the most expensive part of renovation. The bracing is critical for building stability, but the purlins could be a borderline question. The building did survive the major snowstorm of 1979.

3. Contact the local building authorities and let them know of the problem, since it is a life/safety issue. Then wait for the Owner's "blood sucking" attorney's to call me.

Ok fellow engineers, how about some input on this. I think it is a question we all may face at sometime in our career. What say you?

 

[Mattman]

You must do your part to protect the public safety. The first course of action is not an option.

As for Option 2, you must use your engineering judgement as to whether the x- and knee bracing is sufficient for stability. Look at it hard and decide on which side of the "borderline" the purlins fall.

After making that determination, inform the owner, in writing, and in sufficiently strong language, what must be done. You must put this in writing to cover yourself. Then talk to the Owner and explain the severity of the situation and the necessity of the work. Try your best to have it remedied and end the problem there.

If the Owner refuses have the work done to bring the building to a stable condition and you feel it is a danger, write the Owner again about the situation, your concerns, and the required repairs- and copy the building department. You have then done your duty to the Owner, and to the public.

Remember- the public safety is your concern; not the Owner's pocketbook and not the letter of the code. Yes, you must design to the code as a minimum, but you are not obligated to call the building department every time you see a minor code violation. Bring them in when the public safety is compromised and you have reached a dead end with the owner.

Good luck!

 

[haynewp]

Who hired you to look at it to begin with? It wasn't the owner?
Metal buildings collapse all the time, and if the manufacturer thinks it's not safe, it's probably pretty bad off and it's just been real lucky. Somebody could have been shoveling the snow off in 1979 is why it didn't collapse then.

I'm faced with a bad situation on a very old building that shouldn't work at all. And we are making significant modifications to it. I brought this up to my boss and he said it was all going to get grandfathered in. [flush]

 

[dik]

Over the years, I have developed a personal dislike for pre-engineered metal buildings; don't take me wrong, they have some excellent engineering.

I've been involved with a few of them and have run into real problems reinforcing them and modifying them and re-roofing old ones. Most owners don't understand that if you 'knock out' the end column of a frame, you may have to reinforce the roof 3 or 4 bays away. They also don't understand that the engineering fees for a simple modification can be many thousand dollars.

You have a problem if you are required, in your area, to advise the building department of safety issues. If you are *absolutely* certain that a problem exists, then you have little choice; you may want to contact your insurance guy to get some guidance on how best to address the issue.

If you are not obligated to 'blow the whistle', then you can inform the owner that the matter *must* be repaired and leave it to him. Also advise him that if he does nothing, then his insurance will likely be void, in the event of a collapse and, if someone is injured, he could be held criminally negligent. In the event that nothing is done, then inform him that for your own liability that you must proceed to the next level and advise the building department.

It is now summer and unlikely that snow would be an issue (if it's a load problem and it hasn't been stressed to the point that it's in imminent collapse). On a positive side, if it's deformed, then it will likely behave elastically from now until it collapses <G>.

You may want to contact the client and inform him of your dilemma, and that you are bound by law to contact the building department and have no choice. It's the manner that requires a little finesse. My problem is that my wife says, &quot;I have no tact.&quot;

If the matter can be safely remedied by next winter, you may want to contact the owner and suggest that he proceed with the work, subject to him advising the building department that this remedial work is ongoing. He's not going to be happy, and by taking this proactive approach, he is demonstating to the building department that he is a responsible corporate citizen and they may grant him a fair amount of latitude. In our jurisdiction, remedial work is covered by a separate section of the building code and it may not be necessary for him to pay for a building permit. This is to encourage people to repair things.

Inform him that you would be pleased to help him out of his problem and politely inform him that &quot;you're only the messenger...&quot;, but that he may want to contact another engineer, for a second opinion, but caution him that another engineer is bound by the same regulations of informing on life safety issues.

We have a good enough rapport with the building department that we would likely inform the owner that we'll get them involved, 'cobble' together a temporary bracing measure and likely meet the building inspector on site to discuss what is going to be done. The temporary bracing may be the least costly manner of repairing the overall problem.

You may need some sound advice from Ron...

 

[BigH]

If you are in Canada - you might want to contact the Provincial Professional Engineering Assn and discuss the matter with their Enforcement official or director of Professional affairs. Or, you might be able to discuss with the Assn's Legal Counsel. I would hope that they would be able to lead you in the right direction of action. I agree that the public safety is of major concern. If there is even a hint at an immediate problem, you might not have the time to go through contacting the owner singularly, then only if he doesn't respond, then him with copy to city building department. In such a case you probably would need to do the second letter first. Good luck.

 

[JAE]

dik - based on your first sentence...you are my hero! I've always felt the same about these tinsel buildings. They serve a purpose but, man are they light. All our storms here in the midwest, USA end up with some pre-engineered building being blown down somewhere.

I also agree with the insurance tact - if the owner is made aware of the true risk they are taking, then they can make a more informed decision.

The letter to the owner is a must. This, with a follow up phone call (documented) will place the burden squarely on the owner. You also must make sure that in your letter and other documentation, you clearly outline for them the risks inherent in the current situation.

Sometimes I go so far as to present some clean numerical examples to them that they can easily visualize. - Specifically ultimate failure loads such as the depth of snow that would just meet the codes, the depth of snow that would cause failure, and the depth of snow expected in your area. With documented reasoning like this, the owner is faced with a clear understanding of the risk/choice he's making.

I'm not so sure that a call to the local building dept. is the best way, or a required way. Check out your local engineering licensing board laws or call them directly for guidance on the issue.

 

[jheidt2543]

Thanks all for some good tips and very good discussion. You all have confirmed my orginal thoughts regarding the NECESSITY of getting this resolved. It is somewhat delicate (as the Wicked Witch of the West said in the Wizard of OZ), the public must be protected and yet some diplomacy must be used to hopefully preserve a client relationship. A formum like this helps sift through to the important points, thanks for all the responses.

Metal buildings, like every other building material, have their place and limitations. Owner's can do some strange things to their buildings without thinking of the consequences and there is not a lot of FS room in a metal building.

 

[BigH]

With your kind permissions as a side note - I'm a geotech, not a structural type - but a few years back, I recall, an Engineer was brought up on charges by the Ontario Provincial Assn of Professional Engineers (PEO) and it had to do with pre-fab metal buildings. A competitor brought the charges as, it appears, he was always being &quot;undercut&quot; as the accused used calculations that would permit a 10% or so reduction in component thickness compared to the accuser's calculations. Anyway - as it turned out in the hearings - there were &quot;no codes&quot; to follow specifically and some historically old professor brought out a 1936 (I think) paper in German to back up his expert contentions. In the end, there were something like 3 revisions to the &quot;expert's&quot; calculations/position - but, in any event, they found the defendant guilty anyway. This blew me away at the time. But - for all out there involved with metal buildings - it might be instructive to find the article - it was published in Engineering Dimensions and I think it was in 1997 or 1998. I'll try to find out and pass on details. Best regards,

 

[dik]

Just some ramblings...

JAE:
I have an excellent rapport with the local CBO, as well as those in the surrounding areas. I often field informal technical questions from them (at least once every couple of weeks, the most recent being a couple of days ago); it's a mutual respect 'thing'. It's possible to meet with them on a semi-formal basis... In the end, however, the correct remedy would be undertaken.

BigH:
I'm not sure that I'd get the professional association involved at this point. I'm of the mindset that if I'm not prepared for an answer, I'd just as soon not ask the question! I'm pretty sure that their reply would be prescribed...

Timing is good... no snow loading for a bit.

In general, I'd likely provide a quick temporary fix to make sure things are safe, and 'wing it' and allow the owner to make the 'correct decision'. If there was no activity, then I'd take the next step.