4 Myths About Construction Debunked

Construction is something you probably either love  or hate, depending on your commute or profession.   Obviously, as a civil engineer, it’s something  I think a lot about, and over the past 6 years   of reading emails and comments from people  who watch Practical Engineering, I know that   parts of heavy construction are consistently  misunderstood. Also, I talk a lot about failures   and engineering mistakes in my videos because  I think those stories are worth discussing,   but if that’s all you ever hear about the  civil engineering and construction industries,   you can be forgiven for having an incomplete  perspective of how things really work.   So I combed through YouTube comments  and emails over the past few years   and pulled together a few of the most  common misconceptions. I’m Grady and this   is Practical Engineering. In today’s episode  we’re debunking some myths about construction. This video is sponsored by Brilliant,   the best way to learn math and science  through problem solving. More on them later. If you’re one of those people who hate  construction, this is probably a frustrating   image: one guy running the excavator and  everyone else just standing around just watching.   It seems like a familiar scene, especially  when the project’s schedule is dragging along.   But, looks can be deceiving. Think of it this  way: contractors are running an extremely   risky business on relatively thin margins. In  most cases, they already know how much money   they’ll be paid for a project, so the only way  to make a profit is to carefully manage expenses.   And what’s their biggest expense? Labor! A  worker standing around with nothing to do   is the first thing to get cut from a project.  Individual laborers might be paid hourly, but   their employers are paid by the contract and have  every incentive to get the job done as quickly   and efficiently as possible. So why do we see  workers standing around? There are a few reasons. Firstly, construction is complicated. Honestly,  it’s a logistical nightmare to get materials,   subcontractors, tools, equipment, and  workers in the right place at the right   time. Almost every task is sequential, which  means anything that doesn’t line up perfectly   affects the schedule of everything else.  Construction is a hurry-up-and-wait operation,   and the waiting is often easier to spot  than the hurrying. Most of the folks you   see on a construction site, whether they’re  standing around or not, have been or will be   hustling for most of the day, which leads me  to my second point: construction is hard work. Anyone working in the trades will tell  you that it’s a physically demanding job.   You can’t just show up at 6AM, run a shovel for 10  hours, go home, and do it again the next day. You   need breaks if you’re working hard. Standing  around is often as simple as that: workers   resting from a difficult task. Plus a person with  a shovel isn’t that useful when you have a tracked   excavator on site that can do the work of 20.  So, the laborers you see outside of machines are   often doing jobs that are adjacent to the actual  work like running tools, directing traffic, or   documenting. That leads me to my third point: not  everyone on a construction site is a tradesperson. Keeping an eye on things is an actual job,  and in some cases it is more than one.   Inspectors are often on site to make sure a  contractor doesn’t misinterpret a design or   build something incorrectly. An engineer may be  on site to answer questions or check on progress.   And trust me, you don’t want us anywhere  near the cab of a crane or excavator.   Safety spotters are sometimes required to  keep workers out of dangerous situations.   Plus, foremen and supervisors are on site  to direct their crews. These folks are doing   necessary jobs that might look just like standing  around if you’re not familiar with the roles. Lastly, construction is often out  in the open unlike many other jobs.   Confirmation bias makes it easy to pass by  a construction site in a car and notice the   people who aren’t actively performing a task while  ignoring the ones who are. If those construction   workers stepped into any office building, they  might see you hanging around the water cooler   talking about your favorite YouTube channels and  start a rumor that office workers are so lazy. I made an entire video comparing “Roman concrete”  to its modern equivalent, but I still get emails   and comments all the time about the arcane secrets  possessed by the ancient Romans that have since   been lost to the sands of time. It’s not true,  really. I mean, the ancient Roman concrete used in   some structures did have some interesting  and innovative properties, and the Romans   did invest significantly in the durability of  their streets and roads. But, I think a Roman   engineer would be astounded to learn that most  modern highways handle hundreds of thousands of   trucks that can weigh upwards of 80,000 pounds  before being replaced. And, I think a Roman   engineer might wet their toga if they were to see  a modern concrete-framed skyscraper. There are a   few reasons why it seems that the Romans had us  outclassed when it comes to structural longevity. First there’s survivor bias. We only see the  structures that lasted these past 2,000 years   and not the vast majority  of buildings and facilities,   which were destroyed in one way or  another. Second, there's the climate.   I haven’t personally been to the parts of  the world surrounding the Mediterranean Sea,   but I hear most of them are quite nice. Cycles of  freezing and thawing are absolutely devastating to   almost every part of the constructed environment.  The ancient Romans were in an area particularly   well-suited to making long-lasting concrete  structures, especially compared to the frozen   wastelands that some other of Earth’s denizens  call home. Finally, there’s just a difference   in society and government. Ancient Rome was wildly  different from modern countries in a lot of ways,   but particularly in how much they were willing  to spend on infrastructure and how they were   willing to treat laborers. Modern concrete mixes  and roadway designs are far superior to those of   ancient Rome, but our collective willingness to  spend money on infrastructure is different too. I think a lot of the feedback I get on Roman  construction is based on the extremely pervasive   sentiment that “we just don’t build stuff like we  used to.” It’s an easy shortcut to equate quality   with longevity, especially for infrastructure  projects where we aren’t directly involved in   managing the costs. I regularly have people tell  me that we shouldn’t use reinforcing steel in   concrete, because when it corrodes, it decreases  the lifespan (which is completely true). But also,   unreinforced concrete is essentially  just brick. And not to disparage masonry,   but there’s a lot it can’t  do in structural engineering. A lot of people even go so far as to accuse  engineers of using planned obsolescence - the   idea that we design things with an intentionally  limited useful life. And I don’t know anything   about consumer goods or devices, but at least in  civil engineering, those people are exactly right.   We always think about and make conscious decisions  regarding lifespan during the design of a project.   But it’s not to be nefarious or create artificial  job security. It’s because, in simplistic terms,   the capital cost of a construction project and  its lifespan exist on either side of a spectrum,   and engineers (by necessity) have to choose  where a project sits between the two.   Will you build a bridge that’s inexpensive,  but will have to be replaced in 25 years,   or will you spend twice the money for more  concrete and more steel to make it last for 50?   We make this decision constantly when  we pay for things in our own lives,   choosing between alternatives that have  various costs and benefits. But it’s   much more complicated to draw that line as the  steward of tax dollars for an entire population. That’s why engineering exists in the first place.  With an unlimited budget, my 2-year-old could   design a bridge that carries monster trucks  over the English channel for a million years.   Engineers compare the relative costs and benefits  of design decisions from start to finish to meet   project requirements, protect public safety, and  do so with the limited available resources. Part   of that is evaluating alternatives like the cheap  bridge versus the expensive bridge, plus their   long-term maintenance and replacement costs to  see which one can best meet the project goals. In   that case, planned obsolescence means being a good  steward of public money (which is always limited),   by not gold-plating where it’s not necessary so  that funds can be used where they’re needed most. There’s a story about legendary astronaut John  Glenn being asked by a reporter about what it felt   like to be inside the Mercury capsule on top of an  Atlas LV-3B rocket before takeoff. He reportedly   said he felt exactly how one would feel sitting on  top of two million parts - all built by the lowest   bidder on a government contract. And indeed, most  construction projects are contracted using bids,   and regulations require that public entities award  the contract to the lowest bidder. Those rules are   in place to make sure that the taxpayer is getting  the most value for their money. But, it doesn’t   necessarily mean that our infrastructure  projects suffer in quality as a result. Most construction projects are bid using a  set of drawings and a book of specifications   that include all the detail necessary  to build them. An engineer, architect,   or both has gone to great lengths to draw and  specify exactly what a contractor should build,   often to the tiniest details about products,  testing, and procedures. You can see for yourself;   just google your city or state, plus  “standard specifications,” and scroll   through what you find to get a sense of  how detailed contract documents can be.   We go to that level of detail in defining the  project before construction so that it can be   let for bidding with the confidence that  an owner will end up with essentially the   same product at the end of construction,  no matter which contractor wins the job. Bidding on contracts is a tough way to win  work, by the way. Imagine if on January 1st,   your employer gave you a list of all the tasks  that needed to be complete by the end of the year,   and you had to guess how many hours it would take.  And, if you guessed a higher number than your   coworker, you got fired. And if you guessed lower  than the actual number of hours it took, too bad,   you only got paid for the hours you guessed. It  might incentivize you to look for innovative ways   to get your job done more efficiently, but  (admittedly) it might also encourage you to   cut corners and ignore opportunities to add  value where it’s not explicitly required. Many public entities are moving away from  contracting using the lowest bidder model   for types of procurement that allow them to  recognize and award other measures of value   than just cost like innovation, schedule, and past  experience. These alternative delivery methods can   help foster a more collaborative relationship  between the owner, contractor, and designer,   making the construction process smoother  and more efficient. But, the lowest bidder   model is still used around the world because it  generally rewards efficient use of public funds.   After all, John Glenn did make it safely to space,  became the first American to orbit the earth,   and came back with no issues on those two  million parts provided by the lowest bidders. If you’ve ever played minecraft, you know  that at a certain depth below the ground,   you reach an impenetrable layer of  voxels called bedrock. And indeed,   in most parts of the world, geologic layers do get  firmer and more stable, the farther down you go.   Engineers often take advantage of this fact to  secure tall buildings and major structures using   deep foundation systems like driven or drilled  piles. “Bedrock” is such a familiar concept   that it’s easy to look at the world through  minecraft-colored glasses and assume there’s   (always and everywhere) some firm layer below -  but not too far from - the surface of the earth,   and all tall buildings and structures must sit  atop it. But, the real world is a little more   complicated than that. Different geologic layers  may be considered bedrock, depending on whether   you’re a well driller, foundation designer, pile  driver, or geology textbook author. There’s no   strict definition of bedrock, and there are  vast spectrums of soil and rock properties   that might make stable foundations depending  on the loading and environmental conditions. In engineering especially, there doesn’t always  exist a firm geologic layer at a reasonable depth   below the surface of the earth our buildings and  structures can be attached to. And even if there   is, that may not be the most cost-effective way  to meet design requirements. There may be shallow   foundation concepts that are appropriate (and much  cheaper) depending on the situation. There’s a   famous parable about a wise man who built his  house on the rock, but not every wise man can   afford a piece of property on the rocky side of  town, especially in today’s real estate market.   Civil engineers don’t always have the luxury  of founding structures on the most stable of   subgrades, so we’ve come up with foundations that  keep structures secure on sand, silt, clay, and   even floating on water. When the rain comes down,  and the streams rise, and the winds blow and beat   against our structures, they almost always remain  standing no matter what the geology is below. Building infrastructure is such a cool  confluence of technical fields, combining   engineering, public administration, construction  management, and a whole lot of skilled trades. I   think one of the easiest shortcuts to success in  school, your career, or just life in general is   finding opportunities to mix and match areas of  expertise like this. In niches, there are riches,   as they say. But it’s hard to gain technical  knowledge in outside industries. That’s why I’m   thankful for Brilliant, the sponsor of today's  video, for providing interactive courses in   topics that interest me, like this one about using  logic to debunk false information. Sound familiar?   My videos give a thousand foot overview of  many parts of engineering, but maybe you’re   watching one of my videos and thinking, “This  is for me. This is what I’m interested in.”   Brilliant gives you the ability to dive into  math and science topics so you can really learn   them and get ahead in your studies or your  career. The website is beautifully designed,   and they’ve put a ton of effort into finding the  best ways to help you gain technical knowledge   and skills. Learn to think like a scientist,  engineer, or construction manager completely free   at brilliant.org/PracticalEngineering. You don’t  pay anything to sign up, and the first 200 people   that use the link will get 20% off an annual  premium subscription. Again, it’s completely free   to sign up. That link is in the description. Thank  you for watching, and let me know what you think.

Channel: Practical Engineering

Views: 1,780,191

Keywords: Myths, Debunked, Construction, lazy, hurry-up-and-wait, tracked excavator, Safety spotters, Roman concrete, lowest bidder model, Bedrock, durability, survivor bias, Mediterranean Sea, freezing and thawing, concrete mix, reinforcing steel, minecraft

Id: 22W5tRWbUVI

Length: 14min 36sec (876 seconds)

Published: Tue Jun 21 2022

Reddit Comments

[u/Thorusss]

Practical Engineering videos are always well researched, surprising and entertaining.

I am sure this will be as well.

Edit: it is!

[u/crappyroads]

Highway Engineer checking in. This guy is 100% spot on on everything. With respect to low bid contracts, he mentions that bids are starting to get scored on technical and innovation as well as price and that's absolutely true, it's a major feature of most consulting contracts that are released by agencies (State DOT's). The don't just blindly award the lowest bidder.

That being said, not all players operate strictly above board. I've certainly been privy to some contractors who's MO is to basically look for holes in the job specifications and then exploit them to make their money in change orders once they win the contract at low bid.

That's why it's important for us engineers to write mountains of basically legal technical documents that accompany every project we design, even though we might not always be 100% successful, it helps to prevent that kind of behavior.

edit: Oh yeah, I did want to say one thing about foundations. Geotechnical engineering is sort of the dark arts corner of civil engineering. Geotechs have to take sample information from cores and borings that represents like 1 millionth/billionth of the volume of the soil impacted by the project and produce a design from it on which the entire projects integrity depends. It doesn't always go perfectly. The current Millennium Tower settlement issue is the latest big example. They tried the shallow strategy but it turns out that the soils aren't behaving that way they though they would so they're now rescuing it with the deeper foundations to solid rock. I definitely don't envy the geotechs in their work, even if it's pretty cool.

[u/outtyn1nja]

One of the problems I have with projects that go to the lowest bidder is that they always go way over budget. Does this not defeat the whole purpose of a lowest bid?

[u/Mission_Flight_1902]

Rebar is bad for building most buildings. The building will not last much more than a century. A brick or stone building will easily last centuries and spending a bit more to get a much longer lasting building is better. If my house had been built of rebar it would have been torn down.