• Field Notes 13.05.2015 2 Comments

    Have you seen the new acronym “BECx” – building envelope commissioning? No, it has nothing to do with GANA’s BEC. I’m still trying to get straight in my head why this is needed. After talking to a former colleague, it seems like this is NFRC all over again, with another set of players trying to get their noses under the building envelope tent. Just last week, I saw the first set of specs that required a Building Envelope Commissioning Agent (BECxA – funny how the acronyms all run closely to and with each other, isn’t it?).

    Basically, building envelope commissioning includes another player on the design team – during design development or schematic design – whose primary role is to confirm that the specifications adequately address the building envelope’s various performance requirements. That means everything, not just glass and glazing, but also brick, panel, precast and other wall assemblies, will all have to meet the same performance standards we in the glass/glazing biz have come to know and love, such as ASTM E283, E330, E331, AAMA 501.1 thru .6, etc. The building commissioning standard, ASTM E2813, is meant to address energy, environment, safety, security, durability, sustainability, and operation (Section 1.6) issues, but as of this writing it doesn’t include verification or checks for structural issues, such as seismic, deflections. Why not? I couldn’t get an answer.

    The building envelop commissioning agent frequently weighs in on the design, checking envelope wall submittals, helping spec correct materials/wall systems/constructions, and then testing either with pre-construction mockup testing and/or post-construction field testing. The people making the argument for commissioning say the commissioning protocol confirms that the architect’s specs actually get delivered. Really? Doesn’t the architect or their consultant already do field checks?

    I’ve yet to see a project in which there’s a wholesale change to different materials (system, glass, etc.) after field testing is completed, or after shop drawings are approved, have you? The proponents seem to think that a major switch-out for cost savings by the GC or glazing sub is “done all the time.” I certainly don’t know any architect or owner who would approve a pay request IF that were done.

    For smaller scale projects where the schedule and cost of conducting a performance mockup is not justified, the frame and glass manufacturers, along with NFRC certification, provide validation for the system as a whole in previously conducted air, water, and performance testing. Field testing for air/water integrity isn’t increased or lessened over typical specifications. Unless the building commissioning agent makes them test all over again to confirm the same performance before approval of the product for a given project, the validation comes in field testing of that existing product line. Doing thermal testing in the lab is hard enough; doing it on-site is much more difficult. Isn’t NRFC certification enough to confirm thermal performance? Why go through the trouble of conducting another thermal test if it’s not?

    So, the unanswered questions for me are:

    1. Who is advocating this?
    2. What value does it add to the project that justifies the additional costs over what’s now typically required?
    3. Is the owner willing to pay the costs of another consultant on the design team or added costs to install the walls?

    Plus, the standard covering the commissioning agent certification (E2813), calls for competencies that in practice will limit the qualified people to those with more than 20+ years in the business, and who have worked for a GC or exterior wall subcontractor delivering these goods. Naturally, the more experienced the person is, the more expensive the cost of providing commissioning services will be.

    For large projects, we all know mockups can prove structural, air and water performance, as well as some thermal validation. Field testing does the same, with or without a pre-construction mockup. Thermal can be proved prior to construction, notably if an NFRC-certified set of products (glass, spacer, and framing) is furnished. Does the owner really want to pay to do air, water, thermal and structural testing in the field on an installed wall if a pre-construction mockup wasn’t done? And, do we really need another player whose hand needs to be held to prove what we’re doing is what we said we’d do? Or, is it that the other wall systems (not glass and glazing) need to be validated?

    Maybe the other wall systems haven’t been held to the same standard as we in the glass and glazing biz have been, and that this is the way to catch them up to our world? I’m not sure; no one’s ever explained it to me. This scenario opens up a whole ‘nother can of worms I’ll hold for a future blog.

    Please, I’m slow on the pickup: just why is another player required? And what value do they add to the project? I’m not seeing the need – not yet, anyway. I’d love to hear from the advocates for building envelop commissioning.

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  • ENR’s annual construction photos issue is out, and a glazing-related photo made the cut (see slide 19). Congrats to Jeremy Takada Balden at Morrison-Hershfield, the consulting outfit. It was a picture of one of his co-workers leaning over the 39th floor edge of what looks to be a unitized curtainwall, with the cityscape below him—nice shot!

    There’s also a shot of the workers rappelling down from the installation of the glazing panels at the new Anaheim Regional Transportation Center, which features an arch structure about 100 by 400 feet long, with LARGE diamond-shaped openings between the steel members that look to be glazed in ETFE panels. I saw a presentation last April at Enclos’ Facades+ Conference in NYC about this project. Talk about complexity–there weren’t many repeating lites. What was also interesting was the glaziers have to use mountain-climbing techniques from inside the structure to get to the glass surfaces. No small task that, and I know a lot of glazing pros not up to that effort, myself included. Maybe about 100 pounds ago …

    Another cool one: a hanging stage over the NYC skyline, in which the wire ropes and safety lines are the only visible means of support in the photo, taken when the stage appears to be 80 stories up. Nothing else underneath it.

    The ENR editors pointed out the judges included one safety expert who disqualified any picture that included obvious safety violations. In the M-H photo mentioned above, the full body harness and lanyard tied back into the building are obvious. With the Anaheim guys, you can see their safety lines. And, the winning photo for the first time this year was taken with a smart phone.

    Deb Levy and staff at USGlass: maybe there’s an idea here for an all glass/glazing/fabrication photo contest? If nothing else, with all the smart phones out there, I’ll bet there’d be some pretty dynamic pictures.

    BEC is approaching, so I hope you’ll attend. GANA’s annual meeting the preceding three days also looms. I’ll be covering some of the tech issues the other GANA divisions are working on in a later blog.

    Speaking of photos, my Navy son sent this one from the decks of the USS Whidbey Island, LSD-41. Collin is about to give up sea duty for a recruiting gig here in Kansas. Needless to say, his mother thinks that’s more spectacular than the heavens and stars seen here. You be the judge …

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  • 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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