Retirement reflections #2

I am now mostly retired and doing a lot of traveling to visit my far-flung grandchildren. Most of my days since the last posting in September 2017 (Retirement Reflections https://planetcommercialconstruction.wordpress.com/2017/09/05/retirement-reflections/) have been spent out of the country, but I still am managing a few projects. It is not unusual for folks to get crankier as they get older.  This business gives me plenty of reason to be annoyed as I am regularly interfacing with designers who have a clear concept of what they want in general, in the big picture, but have only limited understanding of either the materials they have specified or how to get them installed and functioning as they envisioned.  To this we have to add the fact that designers have no incentive to get the construction documents exactly right, as they are paid the same either way and contractors will eventually more or less get it all straightened out (if this is not clear to you as a reader, and you want to understand, contact me for elaboration). Another factor helping me to have no regrets about retiring, are bureaucratic resident engineers (RE’s — they do the construction administration on most public works).  Two of my few remaining active projects are public works, and neither involves  architectural precast, though the pieces do have architectural function (this translates to plain gray concrete, smooth form finish).  Each project has had minor bumps on the path from bid to booked job to getting approvals and starting fabrication. Those bumps are a reflection of  the issues discussed above.

The first project is a bunch of large blocks (2’x2’x4 and larger) stacked on the water’s edge, essentially a revetment, similar to large stone blocks that often line a river or coastline. There is a modestly intricate layout, and the contract documents left some (literal) holes, had some mis-counts of quantities (it was a unit price contract), and ignored tolerances (not unusual for designers to think that materials fit together perfectly with 0″ joints and no variation from piece to piece). Also, the documents reflected no understanding of reasonably efficient ways to pin pieces together. Not a big deal, not that unusual. But the documents also had bin blocks as their starting point (but without the keys and keyways that these have) and  called for these to be made of “return”concrete, of what is returned unused to the ready mix plant still in the truck .  Many ready mix companies do make bin blocks out of their returns but making them in different sizes and in a DOT-certified mix is not their cup of tea and so we got the project. Here are the notes from the contract drawing.

We dealt with all the drawing issues and standard submittals. A 4,000 psi mix was specified and we submitted cylinder breaks of 1-day (3500 psi) and 7-day (6500 psi) tests. The response was: “where are the required 28-day breaks” and could only have been uttered by someone who was either very ignorant of concrete (it gets stronger with age and by 7 days had greatly exceeded the specified 28-day strength) or was extremely bureaucratic (I see a box, it must be checked off no matter what) or maybe brain dead (for an engineer). [Side note: clearly  a portion of this person’s job is  ripe for  being handed over to a computer.] Oh well, write a letter and/or break another cylinder, keep them happy, no big deal, but somewhat annoying if you are a  mostly-retired, getting cranky 70-year who still thinks (with no empirical basis) that an industry should improve over time. Luckily, the note and picture below were sufficient to convince a professional engineer that we had met the contractual requirement that at 28 days the concrete had compressive strength of at least 4000 psi.

Another issue resolved. Then the RE (or another party, my communications come via the GC and so I don’t always know who initiates a particular nonsense) asked for a color chart and I had to write them a letter explaining that the contract clearly was based on “return” concrete and no way did that come in a range of color choices.    OK, next they asked for pictures of the concrete so they understood color range. Not 100% unreasonable, but very rookie-ish.  Then they asked for photos of the sand and stone, which makes no sense (if you know a little about concrete) since it is form finish and thus all you see is the cement paste, so the color of the sand and stone are not relevant.   A lot of futzing around for a bunch of blocks.  Maybe we will soon be cut loose to make the stuff.

The other job started with a cut sheet for a standard product – a simple tapered shape for a short bollard  from a precaster far enough away that it was uneconomical to ship, so we got the job.

Looked like the most straight forward item you could get in a plans and specs world .

We submitted a drawing and in return got a revised section showing a large void, with a note stating the new maximum weight of 620 pounds.

The original cut sheet listed the weight and nothing in the contract documents indicated that weight was an issue; you wonder if the designer ignored the weight or if the owner suddenly came up with a new requirement. Either way, what gets the old-cranky-guy juices flowing is when we do the 7th grade math and determine that the revised section they drew will weigh 795 lbs., well over their stated 620 lb. requirement. Why do they bother drawing the revised section if they cannot do the math? They could more easily simply have  given us the weight requirement and both our lives would have been easier.

Then it turns out that they want a stainless steel plate on the very top 8″ x 8″ surface and we are told they want Type 314 Stainless Steel.  My first response: Huh?! What is 314? Second response is to look it up and learn that it has high-temperature oxidation resistance and is “commonly used for furnace equipment, super heater suspensions, enameling grates etc.” My third thoughts: typo (they meant 304, the most common stainless in construction applications) or wacko? No way to tell, write another email and may as well also tell them that their note about gluing it is goofy – would likely result in reduced durability and that 3/8″ thick plate is overkill for a shiny ornament.  Other than being cranky I do not mind; having relevant knowledge is the job of a supplier or subcontractor in this business where the designers are neither required nor able to get to the level of detail needed to actually correctly construct anything. What amazes me is that there are people (they know software but not construction) who think they can easily automate procurement in this industry.

Advertisements

Retirement reflections

I have been learning about this business for 29 years now.  As I transition to retirement I get both reflective and annoyed. Annoyed because certain things do not get better, they may be getting worse, and of course I am crankier than I used to be.   I recently bid some “simple” precast panels for a retaining wall (aka “lagging” panels or “soldier piles”).  I have done a few; therefore I know a little, though not much, about them.

If you are unfamiliar with these structures, here is a primer, created by searching for “lagging panel” (you can try this at home).

The bid documents were created by a very large (well, maybe the largest) multinational design firm.  They showed a detail I had never seen before. Intent was clear: visually cover up the vertical H-beam. But to my limited knowledge the detail smelled of  serious installation/constructability problems and of likely durability problems as well. (If the basis of such thoughts interests you, ask and I will explain).

I called  a GC bidder I knew to be highly experienced with this type of wall.  estimator and he concurred that it was borderline nightmarish.  So I wrote up something for the pre-bid meeting. There were actually 5 separate confusions or errors pertaining to the precast in the bid documents (what about the rest of the project?).  I summarized the main one by asking: Has this use of a slot been fully engineered and is there a known example where it was both successfully installed and durable?

Subsequently, one of the many addenda issued to the bid documents featured a different detail. The revised detail was new to the project and obviously new to the original designers, but is not new to anyone with experience building these piles.

What lessons are implicit in this situation?

Designers sometimes “wing it”

They may have no idea of the best ways to solve a problem and they are under the gun to get the drawings out, so they just take a stab at it. Not uncommon in my experience.

Contractors are designer’s proofreaders and reviewers.

In effect the prebid questions and subsequent RFI’s are people with more knowledge checking and commenting on the work of those actually paid to design but with less knowledge of each specific material.  The cost of all these people-with-relevant-knowledge reviewing the work of those with very limited knowledge  never shows as a design cost; it is included in the overhead of every bidder.

Once-upon-a-time there were “master architects”

Everyone I know who has had to work from historic (100 years or older) drawings is very impressed with the level of detail, precision, and how it generally matches what  was built. There are a multitude of reasons it is no longer possible for an architect to have deep knowledge of what they are designing. Somewhat surprising is how little the process has changed given how much the reality has changed.

Big name implies big size + good marketing, little else.

Small boutique firms often bring much deeper knowledge to the table. In order to stay big, big firms have to be good at getting lots of client work. Owners are not in a position to assess expertise, and particularly the expertise of the people assigned to the project. The firm may have a world-class expert in one of it’s offices, but as in this case, that knowledge never made it to the project. This design firm is considered a leader in “knowledge management”; what must the laggards look like?

This  phenomena is not unique to construction. In custom corporate software, the large consultancies (IBM, PWC,  Accenture, etc.) are always the safe choice (decades ago when I worked in corporate software the mantra was “no one was ever fired for going with IBM).  Many small independents were much better, but not at marketing.

Why IPD is critical to the success of BIM

A model that does not reflect deep, usable, knowledge does not contribute to efficient construction. This was recognized in early experiences with BIM,  and Integrated Project Delivery is all about bringing expertise to the model earlier than design-bid-build does.

 

 

Lessons from small failures – Part II: Designing for durability

If you get to design and build generation after generation of essentially the same structure and you get to study the old problems, then you end up with a mature well-designed product. Over the decades automobiles have clearly become both more reliable and longer-lasting. Not necessarily so with structures, especially when they are not built repetitively, as might be a standardized overpass/bridge over an interstate; but put it in an urban area, jazz it up with architectural features and you may be adding problems. DOT’s have test tracks to learn more about particular pavements. No such luxury applies to anything with even a little bit of novelty. Lest you think the immense challenges of designing for durability apply only to the minor stuff Cary Concrete Products is normally involved with, here are snippets from a recent story.

———————————————————-

After Only Seven Years, New I-35W Bridge in Minneapolis Showing Signs of Age

07/27/2014

Star Tribune (Minneapolis, MN)

July 27 –Cracks emerged in concrete girders. A drainage hole on the bridge deck plugged up. Rust showed above piers. Seven years after the collapse of its predecessor, the new Interstate 35W bridge has been showing its age…Repairs to the system were eventually made under warranty, but not before years of finger-pointing between the state and the lead contractor. Taxpayers also covered some costs.

“Contractors are always very reluctant to give anything,” said Tom Styrbicki, bridge construction and maintenance engineer for the Minnesota Department of Transportation (MnDOT). “They always try to drag MnDOT into it: ‘We did it per your specifications. If it leaks, it leaks.’ ”

[My comments: 1) of course there is finger-pointing. Often problems arise from issues in both design and execution; 2) most contractors eventually fatigue from the battles over specifications that are poorly written (my own experience and informal polls peg error-free specs at 1%) and occasionally enforced to our surprise and detriment. The result of that fatigue is unfortunate but understandable to any subcontractor: ‘We did it per your specifications. If it leaks, it leaks.”]

Full story is at http://www.startribune.com/politics/statelocal/268746561.html or http://enr.construction.com/yb/enr/article.aspx?story_id=id:ZDAtwZvbDEgPAf81w4aA1jHIfPjJuLGNDcMwvg2Pfds8xYrzQnvP5LykSce0mHPo

——————————————————————————————————

Our microcosmic story concerns a minor failure and then thinking in detail what it takes to avoid creating designs with inherent problems. The previous post in this series went into detail about the specific problem we recently analyzed and on how surprised we were by the cause of the failure: https://planetcommercialconstruction.wordpress.com/2014/07/21/lessons-from-small-failures-part-i-searching-for-truth/

To summarize: enough moisture entered an unusually large mortar-filled void. When  frozen it was able to generate enough force to crack concrete.  We say that the piece “failed” but in fact the piece performed exactly as it was designed to perform.  The curbs at the posts in this railing system were not durable because the design did not anticipate what occurred. With hindsight we can easily see what happened.

• The rail assembly sits on the sidewalk (and the sidewalk on the deck)
• Water on the back of the curb flows to a small overhang that is part of the sidewalk
• The sidewalk, including the overhang, slopes to the roadway for drainage.
• Water flows into the mortar that is the bed joint of the curb pieces.
• Moisture in the bed joint moves into the mortar-filled cavity (blockout)
• The mortar gets saturated
• The mortar  gets frozen and expands
• Frozen mortar in the bed joint is not a problem, too small to generate large forces
• Frozen mortar in the block out starts to crack the precast curb
• The crack takes in water, ice forms and enlarges the crack
• Visible large cracks form and the curb piece falls apart.
• In 6 years, about 15% of the pieces at this condition have already  failed.
• All other curb pieces, piers, etc., are in excellent condition.

This is the railing system. It’s on a roadway bridge.

Structural detail from contract drawings.

Architectural detail from contract drawing defines a blockout sized for real-world tolerances.

Early stage of failure.

Visible cracking has occurred in this piece.

Inspecting after removal of cracked pieces and cleaning the blockout. Shows crumbled mortar in foreground.

The foresight to anticipate this is highly improbably. For 25+ years I have been regularly involved with mortar-filled openings, and never before saw a failure of this type. Couldyou reasonably expect someone to anticipate this? Failure required both a large volume of mortar and a large volume of water (and a freezing climate). Rules simply about the size of mortar-filled blockouts would not help. (I am sure such rules exist in <0.05% of architectural firms and <0.5% of engineering firms.)  Avoiding this failure would require you to have imagined this scenario. It only is an issue at the pieces at the posts. If you were using this exact railing on many bridges you would be in a different business and in 5 years or less you would have learned that this particular detail does not work. And you would never use it again.

This can also be a reminder that a BIM with intelligent objects needs both software that can store and apply the knowledge and  an organization that can capture and organize little tidbits like what we learned from this minor failure.  We are not close to doing that in non-repetitive structures.

Lessons from small failures – Part I: Searching for truth

The “failure” here is simply a piece of architectural precast concrete that cracked open much earlier in its life than expected. The piece is part of a system of curbs and railings on a bridge.  Photos were sent to me and I was able to take a good guess as to what was going on. It seemed obvious;  I’d have given odds of at least 8:1 that my guess was right (spoiler: I would have lost the bet).  Here’s what the piece looked like on the plans, in real life, and as a failed piece.

 

The bridge is  7 years old; failures started showing up a few years ago. The problem is only at the intermediate piers; there are no significant problems anywhere else on the railing.

I knew that the steel post had an anchor plate and was bolted to hot-dipped galvanized anchor bolts cast into the bridge deck and that the tube steel post had some sort of serious coating.  The location and pattern of the cracking indicating a lot of force coming from the cavity where the curb piece surrounded the steel post.  My guess was that something was rusting – maybe some non-galvanized bolts were used or the paint on the post had failed or been abraded and was now rusting. In my experience I could imagine nothing else inside the piece that could generate enough force to crack a healthy piece of precast. The precast had epoxy coated bar and the crack did not follow the bar locations, ruling out rusting reinforcement. The Quick-Look report (www.quick-look.us is our service for fast, first-look inspections based on photos sent to us) identified some rusting object, probably the plate,  as the likely cause of failure.

After getting the report based on the photos the owner engaged me to make an in-person inspection. They wanted both a more careful look and some advice on remediation. We went, we looked, and we watched as they opened up one of the cracked curbs. To my surprise, all the metal was clean (the tiny bit of rust on the edge of the bolted-down plate was insignificant).  The mortar that was used to fill the void formed into the precast to go around the plate and bolts was so crumbled that it might have been just coarse damp sand. It was clear that rust was irrelevant and that freeze-thaw action had turned the mortar into a sponge that once saturated could become a large ice cube capable of generating enough force to crack the precast. Once the cracking started, freeze-thaw and chlorides (the piece is on the edge of a bridge that is in the middle of the snow-and-salt-belt) did the precast in.

After cleaning out the mortar fill

After opening and clearing out most of the crumbled mortar

This piece has a barely visible early stage crack.

Lesson One: Sometimes you have to open up a wall to be sure of what’s going on. Sometimes you will get surprises rather than confirmation.  We understand the limits of looking only at what is immediately visible, at what shows up in a photo. True in property inspection and in many other parts of life.  More lessons from this inspection in posts to follow.

Lovely spring day makes everything look better

Today was a lovely spring day and I even got to take a little bike ride. That puts me in a very good mood. So one of those constant screw-ups that occur here on planetcommercialconstruction struck me as funny rather than annoying. Viewing commercial construction as a comedy of errors is not as unreasonable as it might seem.

In other industries people build prototypes to discover problems before they build the real thing. Since we build large-scale prototypes (that is what a new building or road or park is) we are constantly finding new possibilities for errors. Because so little is “standard” in this business, even processes tend to be non-standard. Last month I was surprised when a plant submitted samples of two shades of red, got an order for some mockup pieces with the right mix number attached, and somehow, despite apparent good business process, managed to make and crate up 4 full size gray pieces. I did not laugh when that happened, but it wasn’t yet spring.

Today’s laugh came in the context of a job that is getting overripe. I sent samples to the GC and they took two weeks to get to the designer.  Those were rejected because they had the color and the finish that was specified  (rather than  what was “intended” –  that’s life on planetcommercialconstruction). We have run out of time. So this time I gave the plant a transmittal with the name and address of the designer so samples could go direct and we could get approval and get this into production. This AM I saw an email from Fed Ex saying they had delivered the package. Great!  I sent the designer an email so he would know it was in his mail room. So when I showed up at the office and saw that a carton about the size of two 12″ square samples had been delivered to me I was surprised.

I looked at the label and saw that the plant  (not the same one as switched red and gray) had put the designer’s name on the label, but not his address. I had failed to read and verify everything on the FedEx email; had I done what every sub is contractually obligated to do, which is to read every one of the gazillion pages of paper, email, drawings, etc. that get sent to us in a project and scour them for conflicts, then I would have detected this earlier and avoided the embarrassment of telling a designer the sample had arrived at his office when it was actually at mine.  The good news is that I took a short bike ride today and so it’s just part of the comedy of errors of commercial construction.

Rare pleasant surprise

This posting was inspired by a request for a final waiver. Last summer I took on a tiny job – a single  beam cover (turned out to be 3 pieces when we were done). The job was a poster child for small aggravating jobs that take way too much time in relation to the revenue. It was one of the inspirations for the posting about designers being squeezed. https://planetcommercialconstruction.wordpress.com/2013/10/08/fads-fashions-and-trends-on-planet-commercial-construction/   There was no hostility in the process, just a lot of back and forth and coordination, all way out of proportion to covering a steel beam at a garage door. We were furnish-only and the erector was quite bureaucratic and would not use their normal lifting hardware because of an inconsequential hole size mismatch on a plate. I was so frustrated that I jumped in and ordered eye bolts without waiting for a change order, just hoping that the GC would pay me for the bolts and the fiddling time. (The problem was not mine but I wanted to wash my hands of it and while I normally hate taking risks on extras, it was very <$100). Late in December I was astonished and surprised to find in my mail box a check for the whole contract, including every change order and NO RETENTION. What a pleasant surprise. And this week’s email asking for a final waiver? It only mentioned the base amount.  The contrast between the smooth and rapid payment (at least on my end) and the slow and bumpy process of approvals and coordination was amusing. Ah, the planet of surprises, small and large!

Fads, fashions, and trends on planet commercial construction

 Some planets are static for long periods of time. Some not. One nice thing about Planet Commercial Construction is that it demands attention, so little is routine. Change is rampant.  When the a new or oddball situation repeats, I quickly wonder: is this randomness or a trend?

Three times this year I have been told to ignore the contract drawings.  On a small plaza renovation, my instructions came from the field.  On a decent sized downtown commercial addition, the GC was unable to ever give us a coordinated set of architectural and structural drawings; we were promoted so our shop drawings became the coordination focus. Today on a tiny job (but jam packed with confusion and complexity) where we flagged an A-S elevation conflict for the top of a beam we sat on, the GC said “ignore the contract set, just follow the steel shop drawings.”  Those drawings had followed the unconstructible contract details for supporting our piece and so they showed all sorts of extra plates and angles we did not need. Good bet that it’s a trend. 

What’s going on here? I will speculate.  All were private, CRE-driven work. Overall we (contractors and designers) remain in a depressed industry with low margins. Developers are much better at squeezing and wringing cost out of a project than are public owners and so the architects are working cheap. In turn the fees of they pay engineers are rock bottom. So what were once 80% plans are now “for construction”.  Subs who have to submit shop drawings encounter all sorts of issues but the EOR and maybe even the AOR is not eager to put more effort in.  Sort of implicit design build but under a design-bid-build contract. We keep hoping and expecting that the GC will play a serious coordinating role, but in my experience at best they dabble at it.

This process increases the chance or errors and problems. And despite direction to subs about ignoring the contract drawings, in the event of a serious dispute the GC has a huge ammo chest, since the sub is not likely to be in compliance with the contract drawings.  I find it nerve-wracking.  Am I the only one on the planet witnessing this?