Pole Barns. What a Mess 5

[bigmig]

In my 17 year career I have avoided pole barns. Until now.
Recently landed a pair of jobs because we need the work. One mid size, one fairly large.

Both jobs ended abruptly with the following converation:

Us: We as engineers cannot do that or your building will collapse. Have you thought about maybe doing it like this?
Client: Who are you to tell us what our building will look like. You're fired.

I rarely get fired, but have successfully managed to get fired on 2 jobs...both pole barns in a period of only 4 weeks.
We lost probably 75% of our fee.

I am aware that pole barns are bare bone structures.
I am aware that the only reason anyone would ever hire an engineer to design one is because the building dept. is making them.
I am aware that there is some client contention as to "the GD engineer is not worth that type of money".

It just seems like the attitude out of the gate is one of hostility. We can say nothing right.
Just wondering, am I the only one? Is this unique to pole barns? Feeling like never doing another pole barn as long as I live.

Just frustrated.

 

[Heaviside1925]

Similar story different field and slightly better outcome.
Us: After spending a ton of hours coming up with options for a client and the client finally deciding what they want.
Client: (Goes back to the office and hops on google)
Next day....
Client: "What!! you want that much to design this system? Why?"
Us: "Yes, your system is a highly engineered system, we have to do a lot of work to ensure safety and functionality"
Client: (pulls out a manufactures brochure) "But this company offer an off the shelf system that Almost does everything we're looking for and it cost the same as your engineering"
Us: "Ok, then contact this company and get it from them"
Client: "OK, we will and if you don't want the work, I'm sure we'll find a firm that will"
Months go by.... request for proposal comes across my desk.... Yeah, you guessed it....

OP,
Out of curiosity, were to two client pole barn companies or individuals?
Also, I know the IBC references ASABE concerning pole barn type structures. I never knew this organization existed until I saw it refenced.

 

[JAE]

We've basically told potential clients who want us to "review" and sign/seal a pole barn set of plans that we simply can't - the numbers don't ever work and we can't stand behind it.

Our attituded is ALWAYS "Good Riddance".

Most of these pole barns are that - barns. They are most always built out in the country for farmers/ranchers etc. who have no local building department or inspector or permitting process to deal with.
Once they get a job within a city limits and suddenly find they just can't throw up a building they scramble for the first PE who will do their bidding. Not us that's for sure.

 

[Lomarandil]

Just like contractors, engineers need to remember that taking the wrong job is sometimes worse than taking no job at all.

 

[Brad805]

We refer to pole barns as wooden tents. One of the worst we saw built was 60'x300'-0". No functional roof diaphragm, nor any shear walls. There are guidelines how to use the light gauge tin for those purposes, but nobody follows the screw attachment guidelines to do that.

 

[Sparweb]

Um, I'm not sure if I'm off base suggesting this, but maybe they don't need your services:

https://csbe-scgab.ca/publications/canada-plan-service-archive

Saying "it's on the internet" isn't a particularly trustworthy answer, I get it, but in this case it's the Government of Canada, publishing data prepared by engineers, to assist with construction of agricultural buildings because, of course, they're all pretty much the same and there's no money for "figuring it out" as far as farmers are concerned.

Click "Special Structures (8000)" for several pole barn designs, plus a lot more.

 

[JAE]

It's not the nature of the pole barn that determines whether a licensed engineer needs to review it - it's the location of the barn.
If it is out in the country, used only for agricultural purposes, a PE isn't required - at least in the US. Not sure about Canada.

The trouble occurs when someone wants a pole barn inside a city limit where local code ordinances require all buildings to meet the IBC.

 

[Brad805]

It is the same in Canada. The occupant classification and location determine if the NBCC applies. I looked thru the old drawings in that link, and none seem to cover the main concern most of us have with these buildings.

 

[Sparweb]

"Occupancy"
I didn't expect that.

 

[XR250]

I tend to avoid them. Will only do one if it has metal siding and I can make that provide the lateral stability.

 

[gte447f]

sparweb and others who suggest that these types of structures might not need to be engineered, historically, that is probably correct. If the structure is truly a farm shed, then yes, basically who cares if it collapses onto a stack of hay bales in a snow storm. The problem is, many of these types of buildings are being built as other than farm sheds. For example, in my area they are popular at commercial horse stables that offer boarding for horses and riding lessons to the general public as a commercial business. The riding lesson business model is usually targeted at children (and of course their parents' $$$) as the main audience. These types of businesses are very common in my area, which is a historically rural area that has transitioned into an expensive suburban area of the south's largest city that retains a rural "estate" character as its main selling feature. These "horse farm estates" are usually only a few acres (5-10 max, but often even smaller), which would be a fine size for a couple of horses if the estates were truly private, but as I said many of these estates operate commercial business that house (i.e., over house) quite a few horses and are occupied daily by numerous clients/customers. Without building permits and engineering, these pole barn structures are similar to decks in that the adequacy of the designs and the quality of the construction will vary widely from excellent to poor/dangerous.

 

[LittleInch]

Also I guess that one aspect is that the design codes and calculations allow for some level of redundancy / extra capacity, so if something says it is at say 110% of allowable doesn't in reality mean its going to fall down / collapse, more that it has a reduced margin before it does actually collapse.

Many of the existing pole barns and similar may actually operate at 99% of true capacity at times or fail in a gradual manner, but this is very hard to predict.

Hence you can see the frustration of a client who has never seen his pole barn collapse being told the calculations say it will collapse / be "unsafe".

It will take as usual a fairly extensive collapse injuring lots of people before anyone really gets that. Mind you that doesn't stop decks and baloneys collapsing on a fairly regular basis...

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[canwesteng]

Skimmed the drawings - seems like all the column lines are brace, so the roof diaphragm not needed. I can see that most farmers probably aren't building to plan though

 

[Brad805]

We see these pole buildings used in city limits where the occupancy is not considered farm use. The larger suppliers find engineers to seal these. The 60'x300' building I mentioned was cold storage for a large trucking company. They move goods in and out daily. I have never understood how some justify these to themselves. While total collapse of them might not be common we have investigated settlement problems, and significant lean issues. We stay far far away from the design of these. 9 times out of 10 the owners do not think they needed any engineer and surely do not value any technical input that might add a nickel of cost.

 

[phamENG]

calculations say it will collapse / be "unsafe"

Engineers who say that the calculations indicate these things are a big part of the problem. It displays a general misunderstanding of the code. It's about reliability. How reliable is the building? I can drive an old Pinto around town and not die. But that doesn't mean I can rely on it to do it safely every time - even if I maintain it. That is what our codes are about. It's about ensuring an acceptable level of reliability so we can trust our buildings will be safe and not collapse when we need them to stand the most. Normal operations or a windy day isn't when that happens. So when an engineer says 'yeah, these buildings you've been building are all unsafe!"...they are just discrediting themselves. Sure, they probably don't meet code - so I wouldn't rely on one to withstand code required loading and so wouldn't associate myself with a 'typical' design, but it's important to be realistic when speaking with people. But, then, most engineering programs have been stripped of the humanities and the ability to talk to somebody of a different background is no longer seen as important...but that's another issue...

To get a calculation to say that a certain piece of a pole barn is going to collapse would take a tremendous amount of effort - visually grading that piece, determining the most likely actual stress values at failure, and then figuring out exactly what load would make it fail. Even then it's a guess - because until it fails, we don't know exactly how strong that piece of wood is. We can estimate when certain materials are likely to fail - that's how we do seismic design in a lot of instances - but that's about it. Anyone who says 'the calcs say it should fail' needs to either tighten up their semantics or go back and learn what those calcs really mean.

For the record, because I'm sure this will misunderstood by some, I'm not advocating for designing buildings that don't meet code or making excuses for them. I'm advocating for the need for engineers to understand their audience and speak to their audience on their audience's level and to make sure you know what you're talking about while you're doing it.

 

[mtu1972]

I never did any work on pole barns, but I saw one collapse. Our neighbor in a small town in Upper Michigan was a beer distributor and had a pole barn erected as his warehouse. Our town was about 700 people and he had the barn erected on the empty lot between his house and ours. This would have been in the late 1960’s.

We had a big snowstorm and we were playing basketball in our backyard when we started hearing nails popping and the roof collapsed.

About four years later, in my timber design class, the professor started telling us about a pole barn failure that he had been an expert witness on. I asked if it was the beer distributor warehouse in my town. He asked what I knew about it and when I told him that I saw it collapse, he asked me to stay after class.

Turns out he was never told there were witnesses and asked me what we saw.

He then told me that it was a contractor from southern Wisconsin that had not considered the heavier snow loads in the UP. Our little town did not require any permits, etc., so nothing had been checked and approved. It was rebuilt and is still standing, but has not been used for several years.

gjc

 

[LittleInch]

Phameng - Exactly and the OP (bigmig) says that exactly

"Us: We as engineers cannot do that or your building will collapse. Have you thought about maybe doing it like this?"

Maybe the conversation needed to go something like this:

"We as Engineers writing reports and undertaking design to satisfy the regulator (local authority or whoever) need to use certain codes and use certain worst case design conditions such as wind speed, snow load, rain quantities and material properties supplied by vendors. When we do that for this design, the calculations tell us we are above the allowed maximum figure. Now that doesn't mean that the building will collapse, but it says that it is not guaranteed not to collapse in those circumstances. The bottom line here is that the regulator will not approve the design as it stands. We appreciate that the design may well have been used in lots of places and the buildings are still standing, but that's how the system works. Now there is away around this, but this means there needs to be a few modifications in order to get it past the regulator."

Ok a bit long winded, but if you explain things in terms people can understand (basically you and the client against the regulator) then you might just not be fired from the next one?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[phamENG]

LittleInch - spot on. I do have to be a little careful about leaning on the AHJ, because around here the AHJ will often yield to an engineer. "Oh, it has a stamp? No need to review..." And then it comes down to our ethics and integrity, and very few people want to pay more so we can maintain those. But yes, I've found acknowledging the 'fuzziness' of our art goes a long way in breaking down barriers between myself and architects/contractors/owners.

 

[LittleInch]

Comes down to ethics, integrity and the strength of your insurance policy if indeed it did collapse and your stamped design was shown not to conform to the required code it said it did....

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[JAE]

LittleInch - yes a bit longwinded.

How about:
"There's loading and stress that gets to a point where the structure falls down. You don't want that.
There's loading and stress that's less than the fall down load, but more than what the codes say is safe. That's where you are at now.
If we do A, B and C to improve your structure we'll get below the maximum load/stress that the code dictates as safe! Yay!"

Or:
"Who you goin' to believe? We engineers or your lying eyes?"