"I need you to certify this..." 3

[ANE91]

Owner built a 100ft x 100ft pole barn out of wood, sans permit. Clear-span trusses reportedly designed/sealed by the manufacturer. No engineering for the rest of the building. County found out, and now the owner needs the beams/columns/footings checked to the County's satisfaction. I told the owner that I'd need to dig pits and also check the truss design, but the owner wouldn't pay for all that, so we parted amicably. Apparently the owner knows engineers who didn't need all that; I was just the closest one.

Would you have signed off on the rest of the building (if it calc'd out) without considering the trusses? Was I too paranoid? What would you have done?

P.S. I didn't know trusses that big could be shipped/erected. Perhaps they were split at the ridge...

 

[jerseyshore]

Owner built a 100ft x 100ft pole barn out of wood, sans permit. Clear-span trusses reportedly designed/sealed by the manufacturer. No engineering for the rest of the building. County found out, and now the owner needs the beams/columns/footings checked to the County's satisfaction. I told the owner that I'd need to dig pits and also check the truss design, but the owner wouldn't pay for all that, so we parted amicably. Apparently the owner knows engineers who didn't need all that; I was just the closest one.

Would you have signed off on the rest of the building (if it calc'd out) without considering the trusses? Was I too paranoid? What would you have done?

P.S. I didn't know trusses that big could be shipped/erected. Perhaps they were split at the ridge...

Me no. But I know a lot of old timers who have low PE #s that sign off on literally anything.

 

[TRAK.Structural]

I would have accepted the truss design with proper documentation from the Engineer who designed them. If those documents couldn't be found than I would have done exactly what you did.

 

[JAE]

All I would offer the owner would be to visually investigate the condition of the structure, verify whether it had a rational load path, and write a report outlining my observations, general conclusions and recommendations of any remedial work necessary.

I would not "certify" anything - in fact I would go to great pains in my report saying that it isn't an opinion on the load carrying capacity of the structure and is limited to elements of the structure that are visually accessible.

You might think then that my report is just so much hot air - well it is and has to be as there will always be things hidden from view that could affect the load capacity of the structure. Also - there would be things unknown like the design basis of the roof trusses.

Like jerseyshore - I've known some older PE's who would "sign off" on things like this - for a $200 fee even. Crazy.

...but the owner wouldn't pay for all that...

That tells you what you need to know to run away fast. They don't want to know if the structure is OK - they just want someone to come in and satisfy the county and provide someone to sue once a structural problem arises.

 

[Rabbit12]

Me no. But I know a lot of old timers who have low PE #s that sign off on literally anything.

Nothing like cheapening the profession.

 

[jerseyshore]

Nothing like cheapening the profession.

Yes, but I think that's basically any profession or job. There is always someone willing to take less. In our case it's usually old time engineers that DGAF and will basically charge $400 for their seal in a sense. They don't care what they are signing or taking liability for. Will be someone else's problem.

 

[XR250]

That would be a very challenging structure to design. Guarantee the truss bottom chord bracing ain't right.
On jobs like this, I charge what i would have charged to engineer it in the first place and then add the investigative time.
Usually, the owner finds someone else until they hear what they want to hear.

 

[Greenalleycat]

I would be willing to accept the truss design subject to them providing the manufacturer's stamped drawing (to use some Americanese) and some verification of their construction (did a professional do it? did the manufacturer oversee or do the work?)

The rest of the structure would be a headache and my fee would be 2-3x what it would be to design it new to reflect the risk and the headache
When you reverse engineer something that exists like this you own EVERYTHING so you have to check it all, and that takes a lot of time
Site verification won't be possible for some stuff though and that's where it gets really tricky

 

[gte447f]

I say do what you can to make life as difficult as possible for all involved in projects like these while spending as little effort as possible yourself. That usually just entails turning the project away.

 

[phamENG]

If you had sealed truss calcs and you could verify those were the delivered trusses (shipping paperwork, receipts, visual inspection, etc.), then I'd review the shop drawings and installation details just like I would on anything else I designed.

But for the rest of it, I'm with JAE. The county inspector is just as capable of seeing the things that need to be inspected as I am. If they would require something to be removed to be able to see it and call it inspected, why would I need any less?

 

[XR250]

But for the rest of it, I'm with JAE. The county inspector is just as capable of seeing the things that need to be inspected as I am. If they would require something to be removed to be able to see it and call it inspected, why would I need any less?

I doubt a county inspector is capable of inspecting a 100x100 structure as it would not be prescriptive.

 

[JStephen]

When they built it, did they have plans, was it engineered to some extent by others? Or just some guys saying "Let's put this size beam here, it looks stout enough"?
If somebody's selling "DIY Pole Barn Plans", they might be perfectly adequate.
Or another way to look at it, if you get halfway into the job and determine it is fundamentally inadequate, what then?

In the past, I have seen one or two cases discussed where engineers were called in after the fact, and actually had to coordinate with the state board as to how to handle some things that could have been ethically challenging otherwise.

 

[Eng16080]

Owner built a 100ft x 100ft pole barn out of wood, sans permit. . . No engineering for the rest of the building. . . I told the owner that I'd need to dig pits and also check the truss design, but the owner wouldn't pay for all that. . .

I've been involved in a few projects like this over the years. Based on those experiences, I would absolutely not do this project unless I was actually starving and had zero other work.

The last one I was involved in was a similarly sized barn structure which had wood trusses built by the owner with wood gusset plates. According to their builder, my fix to make the trusses code-compliant would have been more work than removing and reconstructing the entire roof. After that we never heard from them again and also didn't receive final payment for our work. I wouldn't be surprised if they just hired another engineer hoping they wouldn't look as close.

 

[LittleInch]

Owner built a 100ft x 100ft pole barn out of wood, sans permit. Clear-span trusses reportedly designed/sealed by the manufacturer. No engineering for the rest of the building. County found out, and now the owner needs the beams/columns/footings checked to the County's satisfaction. I told the owner that I'd need to dig pits and also check the truss design, but the owner wouldn't pay for all that, so we parted amicably. Apparently the owner knows engineers who didn't need all that; I was just the closest one.

Would you have signed off on the rest of the building (if it calc'd out) without considering the trusses? Was I too paranoid? What would you have done?

P.S. I didn't know trusses that big could be shipped/erected. Perhaps they were split at the ridge...

Whenever pole barns come up here, normally someone says they will never meet any construction code, mainly due to the moment force taken by the pole itself dug into the ground. However there are many thousands still standing after 100 years so it clearly works, but can't be proven to work to a code meant for other types of structures. Ditto how anyone can sign off or accept a sign off when they never witnessed the construction is beyond me. All depends on what the county would accept. Could be virtually nothing, could be a whole heap of work. Best avoided.

 

[ANE91]

Thanks for the sanity check, all. Great responses all around.

 

[phamENG]

but can't be proven to work to a code meant for other types of structures.

Sure they can. People engineer pole barns all the time. The end result may be a bit more resilient than what a typical farmer might throw up with what they have on hand, but they can certainly be designed to code.

still standing after 100 years so it clearly works

The building code isn't about what "works." It's about what will work reliably. Looking at the remaining building stock from a previous error carries with it a heavy dose of selection bias. For every one that is still standing, how many collapsed? Why? (If the number is more than about 0.0015, then it's not as reliable as the building code requires of similar structures built today.)

I doubt a county inspector is capable of inspecting a 100x100 structure as it would not be prescriptive.

Fair point. I guess I was just ranting about after-the-fact inspections in general.

 

[gte447f]

However there are many thousands still standing after 100 years so it clearly works

This is not necessarily evidence that anything "clearly works". Those that are still standing after many decades might be the ones that were built very well. There are also many thousands of pole barns and all other types of building structures that have never been subjected to code required design level forces. There are also many thousands of pole barns that have failed when subjected to less than code required design level forces, and many that have had an abbreviated service life span due to inferior construction. Whether it matters if a hay shed blows away or falls down during a snow storm might be considered debatable to some, but then again, a farmer (and his insurance carrier) might be pretty upset if hundreds of thousands of dollars worth of equipment under the shed also got destroyed, and pole barn type structures are also used for many other purposes that could pose a risk to human lives.

 

[jerseyshore]

This is not necessarily evidence that anything "clearly works". Those that are still standing after many decades might be the ones that were built very well.

Survivorship bias is always a dangerous discussion in our world. It's an argument that owners and builders use often. I always say that buildings don't fall down...until they do.

 

[SE2607]

Survivorship bias is always a dangerous discussion in our world. It's an argument that owners and builders use often. I always say that buildings don't fall down...until they do.

Whenever I hear the comment that something is "over engineered", always by a non-engineer, BTW, my response is "Every building standing today is over engineered".

 

[jayrod12]

If somebody's selling "DIY Pole Barn Plans", they might be perfectly adequate.

I once was called out to a "shed", it was 40 feet x 100 feet for an insurance claim of a collapsed roof. When I get to site and talk with the property owner he said he was working in the shed, heard one bang, then a series of bangs as he was running out of the shed. I asked him where he got the trusses from, he said he site built them. I asked where he got the details, he responds online.

We're in an area of 40 psf roof snow load by the way, and he had used 4" wide strips of 7/16" OSB as the gusset plates. He sent me the details he downloaded from online and they were for a far smaller shed, i.e. your standard garden shed 8x10, and also from the southern states where there was no snow.

It was the first time, but not the last time, I actually shook my head at an owner.

When I actually got to look at the trusses it was a clear unzippering failure at the tension splices of the bottom chords. Once the first one went, the adjacent ones started popping as they tried to pick up the additional load. It was the easiest report I've ever written.