pet peeve with contractors

huangyhg

pet peeve with contractors
you know, it always baffels me that contractors always think they know more about engineering than the engineer themselves.  common beliefs are....
a) the engineer always over does the design.  if they call out (5) #5 bars then it probably only really needs (2) #4 bars to work.
b) engineers love to dream up really complex methods to do things.  we never consider how the contractor will have to do something.
c) the only reason their are #6 bars and larger is for skyscrapers and monster bridges.  there is never a requirement for that size bar other than that.
d) if the contractor has never "seen" it done that way before than it must be wrong, even if the contractor has never installed anything like it before.
i could probably go on and on like this but it just gets on my nerves how people think we are all just idiots.  i mean i have even worked in construction pouring concrete and setting steel when i was younger so i have a pretty good feel what they have to deal with.  it's just interesting that someone will trust their intuitive judgement without any formal training in basic force transfer and design over what someone with formal training in engineering recommends.
any thoughts on this?
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i totally agree with you. i got three as-built plans to do, which will take longer and more work to do than the original design did. i got a hugh 4 pump septic field screw up, a 350 foot long tightrope slope paving mess and a property line 10 foot high retaining wall dug out along the property line with no survey ever done to actually locate the line. all three of these jobs had stop work orders issued by the boro officials in the past 2 weeks, and now they require as-builts for the jobs to continue.i think it mainly all comes down to 1)saving money and 2)cutting a corner if possible. as far as engineering the job by themselves, its a distant 3rd in my book.
aggman,
i can empathize with you.  i've been in engineering for over 25 years now and constantly have to fight this battle with construction contractors.  i caught one guy putting in twice as much temperature steel on a one-way slab because he thought it would make it stronger.  if you try and explain the engineering principles involved, you get that "deer in the headlights" look and then they go off and do whatever the heck they want anyway.  if it doesn't adversely affect the structure and doesn't cost us more money, i'll let them do whatever.  most of my experiences have been with contractors adding more 'cause it just don't "look" strong enough to them.  however, i just recently had an incident where we told the contractor he had to wait 28 days before driving his concrete trucks over new airfield pavement.  he ignored us and started driving around at 7 days because he thought he knew better.
when i was a young engineer of about 5 years experience, i had a construction guy tell me that he wasn't going to let some college punk tell him what to do.  i really don't know how you're suppose to overcome an attitude like that.  i guess the old "blue collar vs. white collar" thing is still around.  it would make an interesting psychological study.
i run into the too light thing a lot too.  it just seems that no matter what i come up with it's not what they think it should be.  i once designed this big crusher support that was 26' up in the air.  i designed a post tensioned foundation into rock and a steel support structure with x-braced frames to support this 150,000# crusher.  i sized everything up adequatly and used like w8x24 x bracing and w10x49 columns.  (six columns with all panels fully x-braced).  the erector comes snorting into the office one morning and tells me there is no way it will work because my columns were too light.  he expected that it would take w12x96 columns to do the job.  i asked him how he came about that number and he says, "lots of experience fixing ones that didn't work!"  he said it would sway back and forth because the columns were so small.  i said well if your concern is sway then to fix that we should beef up the bracing, not the columns.  (i didn't want to change anything because it was already fabricated.)  he said the bracing looked fine but the columns were too light.  after more bantering he storms out saying that when it failed i could call him to show me how to do it.  a few months later the thing starts up and runs really well, just like my calcs predicted and still is 4 years later.  never once did the guy say anything to me about it.
its just interesting to watch everyones personality isn't it?
quote: "i mean i have even worked in construction pouring concrete and setting steel when i was younger so i have a pretty good feel what they have to deal with.
that makes all the difference.
i spent >8 yrs in a state dot. there were a significant number of designers that had little or no field experience. they would often design things that had constructability or traffic control plan problems. this is probably what causes contractors to not trust engineers.
i quickly decided that the best designers had some construction, maintenance or traffic engineering experience.
ps to vmirat: so, what happened to the airfield?
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construction types have a mind of their own.  i kind of like the "deer in the headlights" analogy.  sometimes people's egos' exceed their intelligence.  on the other side i've worked with construction types that came up with excellent ideas or were very good at implementing projects as designed the best they could.  like anything else people should be judged on an individual basis.  best we can do as engineers is to cover our tail and make sure whatever is done under our cognizance is done properly.
"never wrestle a pig.  you both get dirty and the pig likes it."
bagman2524,
i agree with you in that each person must be judged on an individual basis.  i also look to those guys to help determine what is the best way to do something.  they should be consulted with on installation and fabrication aspects because they do know more about that then us.  what i don't like is them telling me beam sizes and rebar sizes because they "know" it will work.
thanks for your input guys.  i am just feeling the need to vent today!
aggman, i've been there many times.  when the contractor argues with me and is belligerent about it, i've learned to ask them to show me their calcs so we can compare notes.  when they refuse to go by the drawings, i tell them i can't make them follow the drawings.  but they need to check with their boss before making an unapproved change because if they are wrong, it's their fault if it fails.  i really don't like it that owners and building officials expect me to check the contractor's work, either.  
i had one contractor who wanted me to pay for the extra concrete used for spread footings, which he overexcavated.  i made a site visit prior to the concrete pour, he asked if i saw anything wrong.  i told him no except the footings looked too big.  i noted in my field report that the footings exceeded the drawing requirements but would be acceptable and submitted a copy to the architect who forwarded a copy to the owner and contractor.  since the footings were larger than what i asked for on the drawings, he poured more concrete than needed and felt i should pay the difference since i failed to point it out.  he shut up when reminded about the field report and the owner told him it was his fault for over excavating.
i totally agree about engineers getting practical experience in constructability.  not sure what the venue should be for that:  college or on-the-job.  i've done a fair share of construction work and visited enough job sites to see how things work...or don't work.  i also try to give the construction guy the benefit of the doubt because, as bagman2424 said, we should judge on an individual basis.  unfortuntely, my experience has been predominately negative.
the military has a similar problem between enlisted and officer (ex-captain here).  brand new second lieutenants have to earn the respect of their troops.  rank can carry you only so far.  interestingly enough, the german military requires that everyone start out as enlisted and work their way up to officer from there.  don't know if that's practical in the construction world, but definitely think engineers of all kinds should spend some time in the field.
actrafficengr:  at this point in time, we are discussing the airfield pavement issue with the contractor.  another example of not knowing engineering.  the contractor claims that the cylinder tests were right on target for strength so they were not concerned.  i had to explain that the cylinder tests are laboratory controlled.  the concrete in the field has been curing in 45-50 degree temperatures, so its strength is not going to match that in the lab.  and, oh by the way, you're suppose to be doing beam breaks for airfield pavements!  i suspect the concrete is ok (12 inches), but that's not the issue.  the contractor went against my directives.
my #1 pet peeve is contractors who think they know just about everything there is to know about just about everything.
most recent example:  i design a rectangular two story building, approximately 7,000 square feet with the second story walls inset from the first story walls on each side.  the building is ~100' x ~55'.  it is mostly conventional wood framing, but a little complicated.  one of the long second story walls doesn't line up with a wall below, and i'm forced to use steel posts and beams under that wall as well as design the 2nd floor shear walls for the additional torsional load.  one of the short 2nd floor walls that does line up with a 1st story wall can't have a continuous shear wall from foundation to roof due to windows in the 2nd story and doors / openings in the 1st story wall.  i had to have shear walls in that 2nd story wall and so i added a beam in between the 2 stories that could handle the moment created by the 2nd floor shear wall.
to cut a long story short, he came into my office and protested / argued everything from need for shearwalls at all to use to squash blocks at tji joists.  all of my explanations were lost on him, including the lateral wind bracing, etc, etc, etc, etc, etc.  after what i thought was convincing him to build it to the drawings, i did an inspection 6 months later to find out that he built it just as he wanted to.  no shear walls at all, you name it.
i called a month later after i gave him repairs / fixes for everything (some major changes were needed, mostly shear walls, and the beam in the wall) to see if they were done fixing the building so i could re-inspect, and he says yeah, they're done, but i don't need to come out again do i?  i go out again and re-inspect of course, and it looks essentially the same, of course.  after his best attempts to convince me of its worthiness (due to his many years of experience and the fact that he has done this before), he says ok, he'll fix it.  he calls a week later saying he got another engineer to sign the letter, but that he really enjoyed working with me, and that together, we built a really good building, and that he couldnt wait to work with us again.  
aggieyank, if contractors were held to the same liabilities we are as engineers, they would not be so willing to change from what is shown on the cd's.  i hear repeatedly, "i'm not responsible for anything after the first year of occupancy."  they just want to build it and move on, leaving us with the liability.  nuts.