• Happy New Year, one and all!  Even though the Eagles lost, the year’s not a complete loss, yet!  And, 2014 seems to be looking especially busy for insurers and lawyers in the architecture industry. Here’s the latest on several high-profile projects they’re engaged in that will impact the glass biz.

    The Nasher Museum’s battle with sunlight reflecting off the nearby Museum Tower is still in the news.  The tower’s owner asked the Dallas City Council to broker an agreement for a fix, but there has been no apparent progress, according to ENR.

    As you’ll recall, there have been several other buildings with reflective “death rays “in the news: one reportedly melting cars in London and the Vdara in Las Vegas roasting sunbathers.  These cases bear watching as they could set legal precedent for designs that cause reflective “hardship” on neighboring properties.

    The Harmon demolition in Las Vegas was in the news again, recently. A judge pulled the demolition approval so the construction insurer can complete its in-house investigation.  The insurance policy is the owner’s, and could impact the pending lawsuits, as the investigation will “…impact the case by adding expert testimony,” ENR reports.   While not party to the lawsuits themselves, the insurer is obviously an interested party, so it remains to be seen if it can be objective.

    The construction contract required the owner, MGM, to pursue insurance relief before suing GC Tudor-Perini.  The insurance company thinks it has discovered “new issues” that haven’t been part of the lawsuits to this point, and that could impact the case or bring future action.  Again, this probably will take years to go through the courts, but the outcome is worth watching for the precedents it sets.

    Beyond the lawyers and insurers, tech continues to chug along and will affect the architecture biz in huge new ways. Notably, 3D printing is moving from prototype/part development to actually constructing buildings.  NASA is looking at it as a way of using materials on the moon to make a form of concrete, with which to 3D print buildings on site.

    A USC professor is already doing this with small-scale structures, and has offered it as a way of building economical low-income housing in developing countries.  One of the attractions is the reduced need for skilled trades to build the structure.

    Can you see the day when a curtainwall contractor further develops a BIM or other 3D model, wraps the actual jobsite in a hi-tech scaffold that has a continuous track running the full perimeter, and on that track, a 3D printer produces the building’s wall?  A few questions to ponder: Would anchors already be in place, or would they be printed separately, with a stronger material?  Would they be welded or fastened to the structure?  Would there be one printer for the framing system (with integral finish/color), including gaskets, and another for the infill, be it glass, metal panels, etc.?  Just think about all the technical issues we deal with every day, and how to automate all the various factors into a printed wall.

    And, who’s to say the building structure itself wouldn’t be built using a large 3D printer.  One question if using concrete:  if the concrete can be set WITHOUT formwork, wouldn’t that be enough of an attraction for a general contractor? I think the answer would be yes.

    Like the learning process most glazing contractors went through in the past, maybe the way to develop these systems is to start with simple storefront wall assemblies, and apply that knowledge to the next type of system, say stick curtainwall, then on to high-rise, high-performance curtainwall.

    As is always the case, experience of past events (Nasher, Harmon) teaches us how to move forward or to incorporate other criteria in design or development of new projects.  Somewhere there is someone who dreams, who takes new technologies and applies them to a new way of doing something that we take for granted can only be done the “old way.”  3D printing may be that, or it may lead to a new or different way that nobody’s thought of yet.  As smart as Leonardo De Vinci was, did he foresee that his self-propelled air screws would one day turn into helicopters?  I doubt the Wright Brothers could see, just 110 years ago, that 747s and Concordes would one day be possible.

    Someone’s going to push the building envelope “envelope” (curtainwall construction)?  Where do you see it going?

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  • Robots build your car and computer, and now they’re laying out interior walls. What are the implications for other building components, including curtainwalls? Read on, or be assimilated …

    We’ve all seen interior partition subs marking floors with chalk lines for metal stud and gypsum walls.  The 4/22/13 issue of ENR had an article about a robot used to lay these out to an accuracy of +/- 1/8”.  The CAD or BIM information is entered into the “laybot” robot, which then moves around the floor at 1.8 – 2.2 feet/minute, even around corners, laying out curved or straight walls.  I wonder if it can be adapted for layout of curtainwall? Some challenges come to mind.

    In any curtainwall job, one of the first tasks the field crews undertake is layout of the wall in relation to the structure.  On taller buildings, the forming of the upper floors is proceeding above, while the curtainwall layout, starting on the first floor, has to predict where the building is going to be long before it’s completed.

    The biggest challenge is that a continuous, full-height curtainwall is not on the slab, it’s off the slab, hanging out in thin air.  So, putting a layout line where the wall will be is not feasible (after all this isn’t drywall we’re talking about) except maybe at the base of the wall.   But curbs and overhanging walls can complicate that.  Additionally, perimeter columns get in the way of putting the layout lines right at the edge of the floor.  That location is further complicated as slab edges  often are not straight.

    So, layout crews tend to “cheat” the line to miss the columns, moving back in on the floor slab to miss the columns.  One of the things the field crews usually discuss with the GC when they first hit the job is:  How much room are we going to need for layout and material storage around the perimeter of the floor?

    Layout in plan is one facet of this, but the layout crew also has to deal with vertical tolerance.  If you’ve ever stood at the base of a tall curtainwall and looked up, it’s surprising to see how straight the wall is (it’s a perspective you can’t get when standing away from the building, taking in the whole of it).  The in/out plumb of the wall can only be seen from that vantage point, or possibly from the other end, on the roof looking down.  It’s a sign of how good the layout crew was.  Specifications often limit plumb deviations to less than 1/8 inch per floor.  That’s a lot.

    It’s always been a minor miracle to me that more buildings and curtainwalls don’t crash into each other.  BIM can help model this prior to start of the work, but when the building actually starts, theory becomes reality, or should, anyway.  Granted, tolerances and designed-in allowances accommodate that, but when a steel structure is erected with tolerances of +/-2” or more, and curtainwalls being built to +/-1/32”, why don’t they bump into each other more often?

    And concrete’s even more challenging than steel in this regard.  At least with steel, you can work from fixed dimensions every time, but concrete’s formwork is repeated over and over again for the height of the building, allowing just a small mistake to have serious repercussions.

    And the horror stories about having to chip concrete to allow a mullion to go by are out there.  In one project I heard about, crews had to chip the concrete floor beam so far back, they had to cut through the rebar, also.  I’ll bet the project structural engineer loved hearing that.

    Typically the 1 ½- to 2-inch tolerance between face of slab and back of wall system is cheap insurance.  It gives the general contractor (GC) some flexibility with the edge of the slab, and allows the curtainwall to accommodate any variance without having to notch slabs.  Anything smaller than 1 ½” ends up with notching requirements later.   Architects don’t like it, as they don’t like to think about how to close off the gap.  But it’s a necessary “evil” which permits an easier installation of the wall.

    Having the discussion with the GC prior to work starting, usually as part of the pre-installation conference, is a good place to get all this figured out.  For example, what the structure erection tolerances are, what the curtainwall anchors can reasonably expect to accommodate for the structure tolerance, and what to do when the inevitable clash occurs.  It may be beneficial to have this discussion as soon as possible after contract award so that everyone, GC, framing sub and glazing sub all get off on the right foot, knowing where everybody’s supposed to be when the wall starts to go up.

    It will be interesting to see who among the curtainwall subs will be the first to set up a robot to do layout work…

    Answer to previous trivia:  CCNY, 1950. They beat the same school both times, and since I know some Bradley grads, I won’t mention who it was that lost both tourney championship games in the same year.    

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  • Field Notes 03.04.2013 2 Comments

    The Glass Association of North America’s (GANA) Building Envelope Contractors (BEC) Conference has come and gone, with some good ground covered. A high point was when Guardian’s Scott Thomsen gave a strong call to action for our industry in his presentation the “Battle for the Wall.”  The key takeaway was if we don’t fight for the role of glass in energy-efficient construction (thermal performance and daylighting), then ASHRAE will force us to the sidelines. Do you want to go to work for the stud wall, stucco and masonry contractors, because ASHRAE’s current emphasis is to greatly downsize the percentage of glass in exterior walls?

    We as a glazing industry should be showing architects  there are many glazing products that WILL increase thermal performance.  Architects will help us win this war, but only if we get smarter about educating them on the newest, most innovative glass and framing products now available.

    We should also be assertive with noting the other construction types have as many problems, as well, that are now coming to light in this energy-conscious age.  As ATI’s John Runkle noted in his presentation on building commissioning, these are things the glazing industry has dealt with for years.

    Notably, when the surrounding wall systems – cavity walls behind masonry or panels, precast panels, or whatever construction –  have to start meeting the same water and air penetration requirements as windows and curtainwall presently do on a regular basis, then that bodes well for the exterior skin, as a whole.

    But there are some down-sides, too.  For example, testing the weatherproofing/air barrier to the AAMA and ASTM standards for water penetration  aren’t  realistic since it never sees that amount of rain in the finished condition if a brick or panel wall is placed over it.  Air test it, yes. But a full-blown, 5-gallon/hour/square-foot water test ON THAT SURFACE isn’t real-world.  Some of this is still in the developmental stage, but I expect it will catch on in one form or another.

    Does commissioning make sense for a total glass curtainwall? Probably not with the current regimen of pre-construction and in-field testing required in curtainwall and window specifications.  There are some that would argue the call for increased testing is an effort by the labs to create more work for themselves.  Yes, I can see that, but what good is it having an air- and water-tight window or curtainwall if the wall around it doesn’t perform equally as well?

    Another high point at BEC was the presentation on Chinese tariffs. Some of the USGNN.com newsfeed had comments from the Chinese manufacturers’ side of the fence that felt the presentation didn’t accurately present both sides of the argument.  That wasn’t likely to occur given the fact the person making the presentation was the plaintiff’s attorney.  When’s the last time a lawyer led a fair, objective and balanced viewpoint on something his clients were paying him to have just the opposite opinion on in order to properly argue their case?  But, the tariff issue is going to be in the news quite a bit going forward.

    One last note:  Having turned the odometer over on my age this year, my brother bought me opening day tickets in Philly next Friday.  And, my no. 1 son bought us Final Four tickets.  Only one drawback to the venue:  basketball was not meant to be played in a football arena, unless they put the court in the end zone.  When watching the game, the Philly Phanatic sitting down the right field line in the KU garb, or in the corner of the end zone in Atlanta with the biggest pair of binoculars known to man will be yours truly.  This is one thing I’ll be able to cross off the ol’ bucket list.  As I review this blog post one last time Monday morning, I hope Wichita can shock the world.

    Here’s hoping the Easter season, with the accompanying onset of spring weather, brings renewal of faith, hope and charity to you and yours.

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