• Today’s post picks up where the one from last week left off, with more of the high points covered at the GANA Fall Conference held in Toronto September 23-25.

    Handrails, obviously, are still getting a lot of attention. Being in Toronto, where so much of the news about guardrails is emanating, it seemed only natural to hear how the Canadians are addressing the issue. CSA’s Dwayne Torry, talked about the A500 standard, which is being developed with cross-representation of regulators, suppliers, architects and users (not sure what that means: installers? building owners?). They’re looking to develop a standard to serve as “a consistent baseline for design.” The plan now is for spring 2015 publication. Like the AAMA/WDMA/CSA standards for doors and windows, it might be beneficial for those of us on this side of the border to pay attention.

    Also, testing of handrails was discussed, both in the pre- and post-construction phases. Most exterior guardrails use the exterior cladding wind load, either from wind tunnel testing or by code, to determine the design load for the handrails. Further research is required to determine if that’s realistic, but no one has stepped up to do that, yet. Likewise, there is now additional attention being paid to more stringent post-installation maintenance requirements – everything from checking glass fittings to checking the connection of the guard rails to the structure, etc. If you install handrails, this is certainly worthy of consideration.

    Not a lot is being talked about the causes of the handrail glass breakage, due in large part to the on-going “who’s to blame” game being played on many projects. It’s not only nickel sulfide, but other causes, such as improper installation (e.g., grommets not installed around bolts passing through the glass, posts not installed vertical or in plane with the glass, etc.). The root causes may not be known for years.

    Associated with the handrail discussion were some of the items covered in the GANA Laminating Division meetings. There was some talk about the edges of laminated glass in handrails, and whether they should be finished, pre- or post-laminating. If the architect uses tempered glass, a finished, polished edge is often specified. But, laminated glass complicates that, as most laminators will polish the edges before laminating, and getting the lites in the laminating sandwich to match up is difficult, plus the laminating layer oozes out from between the lites. One possible alternative would be to polish the glass after lamination, but apparently that’s not easily accepted given the budget and schedule constraints of most projects.

    One thing I learned about that I didn’t know before: using a cementitious material to set laminated glass into sill shoe isn’t such a good idea. The cement-based material can damage the laminating layer. I know for the next project where this comes up, a discussion will be warranted between suppliers and glass fabricators.

    The use of laminated glass in doors, and the effects of clamping hardware and/or patch fittings is still being researched, they’re looking for a door manufacturer to lead the testing.

    One issue that’s starting to surface, and it’s really early on, so no immediate cause for alarm, is whether ceramic frit on spandrel glass is causing the glass to loose strength. There’s no data on this, yet, either. What follows is strictly my take on this, not a lot of consensus, and therefore no conclusions were reached. On one hand, some manufacturers talked about applying frits to glass before the glass was heat-strengthened, in which case they report there’s no loss of strength if the glass gets the proper treatment. But, other manufacturers may be applying the frits as a secondary operation after heat treating, and the re-heating may weaken the glass.

    What’s confusing this was two of the leading fabricators are on opposite sides of the question. One insisted that there is no evidence that ceramic frits were causing breakage due to wind loading, that ASTM E1300 still worked with no drop in performance for heat-treated, fritted glass. Another said there was. So, we’ll have to wait and see where this goes.

    A lot covered. A lot to do. Many of the industry manufacturers are well represented at GANA. We’ll look to cover some of this at BEC in the Technical Committee, especially if it rises to the level that the glazing contractors will start being asked about it going forward.

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  • For those of you who couldn’t make it to the GANA Fall Conference, held September 23–25 in Toronto, following are some takeaways, with more to come in next week’s blog.

    Vicente Montes-Amores of CDC made a presentation about solar radiation that was thought-provoking. He noted that we not only need to consider how much solar energy passes through glass, we should also be mindful of what becomes of the reflected energy. Vicente also mentioned that North Carolina’s rule outlawing low-E glass in residential applications has been overturned, for now.

    The GANA Energy Division talked about developing a Glass Information Bulletin (GIB) on how to mitigate the effects of reflectivity, but many people expressed concern about unintentionally implying that reflectivity is a problem, thus opening up the GIB to being more of a reaction vs. action-type message. A video put out by the vinyl siding folks, regarding vinyl melting due to solar reflectivity, clearly laid the problem at the foot of the Low-E glass currently used in new home construction.

    Exxon’s headquarters in Houston, built in the 1960s, may give a great clue for stopping reflected light off a building. If you don’t allow the sunlight to reach the glass, there’s no need to worry about reflectivity. The building’s architect designed sunshades that are approximately 6-foot-wide that protrude from the building at every floor. The sun only reaches the glass early or late in the day, when the energy isn’t as intense. The glass isn’t filmed or insulated—it’s just plain, old quarter-inch clear. But, Exxon hasn’t seen fit to upgrade it, as far as I know. Such indigenous architecture can be instructive on how people dealt with local climate challenges long before mechanical systems and glass wall systems came on line.

    Other innovative designs might be out there, but if the courts ever determine that a new building owes an obligation to not increase the thermal load of their neighbor’s building, the architecture of buildings will have to respond. For example, if a building gets built with all the innovation on the energy front, but a new building that gets built next door causes changes in the original building’s energy performance, due to shading or reflectivity or 100s of other reasons, how is that going to settle out, and what impact will that have on future design and building?

    The GANA Insulating Division is working on a hot-bent glass GIB in which the glass is heated and formed to a specific radius. Once that is developed and published, the group is going to turn its attention to cold-bent insulating glass. Also on track is a GIB for gas-filled IGUs. When asked about whether the gas-filled units lose any gas over the lifetime of the glass, the answer was non-committal: “There’s no empirical data on that at this time.” This is in a sense like testing fading on finishes, in which you put the glass through an aging process or leave it in the sun to see if the values drop over the years. Isn’t someone working on that for IGUs? To the best of my knowledge, there’s nothing out there that says it’s any less of a problem than it was when gas-filled units first came on line.

    Also, a working group was formed to look at butt-glazing insulated glass without a supporting member behind it, much like the practice using monolithic glass and having just a sealant joint between. Point supported insulating glass can do this, so it shouldn’t be much of a reach to allow this in non-point supported applications.

    Just about the time you think the world is a really big place, something happens that smacks down that theory, right quick. It’s pretty surprising what you find out when you talk about something other than glass at any of these types of conventions. Rick Wright has been heavily involved in GANA for much longer than I’ve been, but it wasn’t until I sat next to him last week that I found out he and I went to the same high school within a few years of each other. Rick, Ed McCoy said to say hi!

    On a closing note: Vicente Montes is a real up-and-comer, I expect he’ll be making an impact on the glazing profession for quite some time.

  • When asked if we can solve a problem, most of us in the glass biz try to find a reasonable solution. I was recently told that Bill Lear (of Lear Jet fame) would fire any employee who told him, “that can’t be done.” What I think he was looking for was, “What are the options? Then, we can talk about what is realistic or reasonable from a cost or schedule standpoint.”

    Think back to IBM’s stock answer No. 3 from an earlier blog: “We can do that, but it will come down to how much time and money you want to spend to do it.” I’m not being facetious, but if an owner was willing to pay for gold-plate mullions, we’d do that. Wouldn’t your company do all it could to meet a customer’s expectation, if they were reasonable and were willing to pay the cost?

    Or, to shorten a schedule, we’d air-ship the material to a jobsite. If the cost for that wasn’t in the estimate, then the cost/benefit would have to be weighed:  if we don’t get it there on time, are there penalties incurred that are more severe than the cost of air-freighting the material? That’s an analysis that has to be determined for any given situation.

    Bringing new products to market is like that, too. The people in research and development vet all the processes for the typical applications, come up with all the parts, make sure the production team can actually manufacture the parts, then work with the installation folks to confirm all of those processes work. Then, when introduced to the market, someone is bound to say, “that’s the product we want to use, but can it do this?”

    A hypothetical situation that will bear this out: a customer brings a project to you that has a curved curtainwall. And, “they don’t want it segmented,” which, of course, is everybody’s initial response, right?  The curve can be in plan or in section—it doesn’t matter. They want to use a standard system to do this, say a pressure plate system, out of a really deep mullion section. So, in thinking about this, some of the problems that have to be dealt with include:

    1. Can all of the members be curved? That includes the mullion, pressure plate and cap, and don’t forget the glass. In the case of the cap and pressure plate, will the snap still function after curving?  Or will the bending tolerances be such that snap functionality is lost?
    1. In rolling the mullion, is one of the walls stretched too thin during fabrication that its structural properties are unacceptably reduced?
    1. What is the tolerance of all the parts, including the glass, when it comes time to assemble them? And, how are any tolerance extremes to be handled between any two parts? When one part is to the extreme plus side of its tolerance, and the one next to it is at its extreme minus side, so that when together, they’re as far apart as can reasonably be expected, what happens?

    So, if you can make sense out of all that in theory, do you take on that work? What are the costs? Can you manage all the coordination that will be required? Can you sell it? Does the decision-maker understand that the application can’t be sold for a standard wall price?

    Usually “we can’t do that” is replaced with a response that’s based on experience. Some of these aren’t shared with the customer, but are discussed internally. In the extreme, rare instances, this could include: We choose not to provide that because we tried to do it in the past and lost our shirt trying. Or, based on that past experience, we now know it’s so difficult to do, we don’t want to do it again.

    Explaining to customers those constraints helps them understand the costs associated with proceeding. What have your experiences been in this regard?

    As someone who likes artistic drawings, M.C. Escher has always been a favorite. Just because you can draw it doesn’t mean it can be done. I guess Mr. Escher never worked for Mr. Lear. Sometimes, Mr. Lear, it can’t be done, even if it looks really cool on paper!

    Credits for this blog topic go to Ron Madeley at TGP, for his stories at lunch and the Escher reference. And, happy birthday to No. 1 son, Jeremy, who in the past month became a father himself. Congrats, and hold on, you’re in for a heck of a ride: love every minute of it!

USGlass Magazine

USGlass Magazine