• From the “Be on Time for Meetings” School of Hard Knocks (or in other words, College of Experience), consider the following hypothetical (maybe so, maybe not) conversation between a glass supplier and several building project team members. Before the glazing subcontractor (the glass supplier’s client), architect, and building owner arrived, the supplier and GC chatted a bit.

    The second question out of the GC’s mouth was: “Now, how much extra glass do we have?” The supplier’s response was classic: “I don’t know; how much attic stock did you buy? Because that’s how much you’ll have. If you bought none, you’ll have none, at least that’s how it works where I’m from.” The GC laughed.

    The glazier showed up soon after, and in front of the GC asked: “How much extra glass do we have?”  The supplier glanced at the GC and smiled, then said: “I don’t know; how much attic stock did you buy?  Because that’s how much you’ll have. If you bought none, you’ll have none, at least that’s how it works where I’m from.” The GC laughed harder.

    Finally, the architect showed up, and in front of the GC asked, “How much extra glass do we have?” The supplier responded: “I don’t know; how much attic stock did you specify for the GC to buy? Because that’s how much you’ll have. If you bought none, you’ll have none, at least that’s how it works where I’m from.”

    The GC said: “He got me and the glazier with that earlier!” and they all laughed. The answer is “I promise, you’ll have enough arrive unbroken at delivery to complete the work without having to call me in a panic saying ‘We don’t have enough to complete the job!’”

    When I first read this, I wanted to know if a follow-up question was asked: “OK, so we have enough to start and possibly finish, but if any is broken on site, how long do replacement glass orders take to arrive?”

    Obviously, the GC, glazier, and architect had discussed attic stock previously, but no one covered this with the glass supplier. Naturally (maybe not?) the glazier would know what he bought, or at least checked with purchasing and / or estimating to know how much they had carried in the budget. It’s easy to look beyond the GC or architect not knowing, but the glazier? At the very least, it’s one thing he would have checked with the glass supplier prior to the meeting, so he’d know the answer when asked.

    Being in the framing end of things, it’s been a while since l’ve last looked at a glazing spec. I can’t remember seeing an attic stock requirement in the framing spec sections I’ve recently reviewed. But, if you’re a glazier, you probably have the response to this question down cold if you’ve familiarized yourself either with your company’s estimate, the specification, and / or your purchase order to your supplier.

    I most appreciate that the supplier had pretty much the same answer each time, except for the dig at the architect about what the specs said – the question didn’t change, irrespective of who was asking it. And, there’s a beauty in the consistency of the response – a lesson for no matter when the questions are asked, whether five minutes / hours / days / weeks apart.

    One also has to give kudos to the GC for not letting on about already having been asked that question. The classic lawyer’s response I would have given the second time the question was asked would have been: “asked and answered.” But, that would have taken all the fun out of it.

    Tags: , , , ,

  • There’s always so much to learn at GANA conferences. If you missed the Fall Conference, or didn’t make it to all the sessions you wanted to, here’s a recap of highlights to supplement my last two posts. Of course, for specific coverage, GANA’s website offers members the opportunity to access the meeting minutes from each of the divisions.

    In the Insulating Division, Jon Kimberlain reported about cold forming insulating glass units, and what possible stress the glass and/or the glass edge seal would be under if the glass were, for lack of a better term, warped when placed in the frame. They looked at a full size glass lite first in a computer-generated model called finite structural analysis, seeing if there were any flaws when loaded to 100 psf when bending the glass in 2-inch increments. They then physically tested a specimen to validate the finite model analysis. They took the physical testing to 8-inch deflection of one corner of the insulated glass without showing any stress in the edge seal under accelerated weather seal testing.

    GANA’s going to join up with Insulated Glass Manufacturers Association (IGMA) to work on any changes to glazing insulating glass units that are only supported on two edges. Presently, most of the fabricators require all four edges to be supported by framing. We’re seeing instances where architects and consultants are allowing construction without framing on two edges. This has implications for how that glass is supported for dead load (and where the setting blocks are located) when the architect wants the glass supported only on the vertical edges. The GANA Annual Meeting next spring will be in conjunction with IGMA, so there should be more developments to report on at that time.

    PIB (polyisobutylene) sealant migration is on-going issue. There was no consensus yet about the cause.  Is it a chemical failure of the primary seal of the spacer? Or, if it’s a squeeze-out issue, is the tried-and-true rule of 4-10 psi edge pressure to affect gasket sealing in captured glazing up for discussion, possibly fine tuning it if the pressure put on the edge of the glass is found to be the cause?

    The reflected energy issues, most notably those concerning building materials in close proximity to coated glass (think North Carolina’s recent restrictions on the use of Low-E glass) will lead to a GIB to address those issues.

    The Tempering Division continues to discuss how to measure wave distortion. Using the dioptric measuring system (it’s what ophthalmologists use to write prescriptions for glasses) may be a more accurate form of measurement than the one presently used. The amount of distortion that’s acceptable depends on the distance and angle of incidence – varying those factors changes the perceived distortion. Software now can filter or indicate the amount of distortion that might be visible, but the settings can lead to misleading projections of the predictable distortion. If one sets the limits too low, you might see a lot of distortion, or conversely, if they’re set too high, no distortion might be indicated. Working with the fabricators for predicting distortion is still a wise strategy.

    Ceramic frit weakening glass for wind load is still out there as an ongoing open issue.  But, no consensus is forming whether this is something the industry is taking a serious look at or not. Megan Headley at USGlass Magazine is looking for input if you have examples of where this has occurred on projects. As would the folks at ASTM E1300 subcommittees that are looking into this.

    The certification of the industry is still in its infancy, but seems to be gaining some traction.  Two strategies appear to be forming.  First, the NACC folks seem to be approaching certification of companies, which takes the tack of looking into their performance practices, safety record, financial stability, quality control processes, administration (contract compliance, communication, etc.).  The other approach is to certify individuals through vehicles such as AAMA’s “Fenestration Masters” program.  GANA is considering joining with that program to add a glass component, adding GANA manuals (Glass, Sealant, PM, and Estimating Manuals) to the core curriculum.

    Laminam, a fabricator of porcelain panels made a presentation of their materials. They’ve glazed large panels (63-by-126 inches) into structural silicone and captured glazing, with geometric or natural material patterns impregnated into the surface, creating a product with a 35-year warranty on color fade. It’s a thinner alternative to stone, which might have some merit.

    Apologies for not wrapping up the report for GANA Fall Conference last week. There was this little parade in Downtown K.C. with 800,000 other Royals fans. My luck has never been to be in town when the local team won a championship trophy, but that’s another story for another time. So, I wasn’t going to miss this one. Even better was me making off with some of Paul Bieber’s money. I haven’t heard from Lyle Hill yet if he wants the same bet for next year after he predicted his Cubbies would be there. Lyle?

    Finally, thanks to the folks at the Washington Glass Association for allowing a review of Fall Conference at their meeting last month. Good crowd, nice reception. Just one comment:  Rick Wakefield should work on his introductions a bit. The liberties he took…I’ll let him explain, but no permanent harm came from it; all in good fun. It was great having a chance to review the conference with those who use the manuals, GIBs and standards GANA’s various divisions develop. Lots of good feedback; thanks WGA!

    Tags: , , , , , ,

  • As I mentioned last week, a lot of ground was covered during the GANA Fall Conference. This is Part 2 in a series whose final length I know not. If you’ll bear with me, I’ll try to wrap up the Laminated Division meeting this week. If time and space permits, I’ll get into the Energy Division.

    To pick up where we left off in Part 1, the laminated folks are also concerned with the long-term exposure of the edge of the laminated glass lite in most typical handrail applications. Of special note: What effect does grout in exposed exterior handrail base shoes do to laminated glass? There’s no recently completed or in-process testing that indicates whether or not the grout and interlayer will play nice with each other. Anybody out there developing a “dry” system with extruded shoes will be ahead of the curve.

    From a development standpoint, it appears there’s also interest in making laminated glass with lites that aren’t necessarily the same thickness. This raises a number of questions. What happens to glass strength if a ¼-inch and 3/8-inch lite are laminated together? Is it twice as strong, or 2.5 times as strong? When different thicknesses are laminated, is there an impact to energy or sound transmittance and the glass’ overall performance?

    And, that’s just the starting point. Let’s go beyond different thicknesses of glass. What happens when you combine glass in laminations that aren’t all glass? For instance, what happens when you laminate glass to metal panels or composites? This naturally leads into a discussion about strength and ASTM E1300. How does laminated glass perform in combination with other products? With all the attention that putting fabric, patterns or pre-printed screens into laminated glass is getting, no one knows how to account for the overall strength of the laminated glass after it’s been fabricated with these “ingredients.”

    In the Energy Division, Tom Culp reported that Climate Zone Borders are being fine-tuned to reflect more recent historical climatological data. The climate zones impact everything about energy performance for a building, not just the glass and glazing. While U-values are trending down between 8 and 14 percent, SHGCs are remaining steady (with some minor shifts) in upcoming code updates. Tom categorized these changes as “fair and reasonable.”

    Learning to identify how products work in combination with each other to achieve the desired thermal performance is going to be a criteria of window and frame selection going forward. For example, when you pick a low-E glass, the zone the project is in may dictate whether or not the glass has to have argon in it, whether the frame has to be higher- or lower-performing, or whether a warm-edge spacer is required, etc., before finalizing a total product selection. Think of it in terms of a “cafeteria plan.” If you pick Option 1 for glass, then you have to do one or several other options, be it A, B, or C. But, if you pick Option 2 for glass and the location is in a different zone, then you may have to select from an entirely new set of options.

    On a separate note, the NFRC’s recent changes haven’t cleared up where that program is going. They’ve made some fundamental software changes that allow faster responses from the CMA program, but their “reaching out to partner with the industry” claim hasn’t been clarified yet. There was some talk of AAMA and NFRC merging their certification efforts. That remains to be seen.

    Also, if you’re not familiar with the LCA/PCR/ EPD/HPD acronyms, you might want to be. The analogy that they are “food labels” for building materials isn’t so much about what’s actually in the product, as it is about how much energy goes into using them in the building, and what their carbon footprint is over the course of the product’s life cycle. For example, they take into account the energy that goes into refining raw materials and getting raw material (stock lengths, for example in aluminum, or glass sheets prior to fabrication) delivered to fabricators, the energy it takes for manufacturers to make materials suitable for installation, the long-term operation or energy cost of the glazing or wall components after installation, and the cost to recycle them (if any). The terms, “cradle to gate” (from the raw material to the fabricator) and “cradle to grave,” (includes cradle to gate and through operation and recycling) are going to become more prominent.

    Tracy Rogers of Quanex reported on a unique glazing approach for retrofit of an existing, monolithic glazed curtainwall that didn’t require any teardown or replacement of the existing window system, nor did it require a relocation of existing tenants. They employed a Quanex spacer applied to the cleaned interior surface of the existing glass, which remained in the existing frame. They then mounted an IGU on the back of that spacer into a Berkowitz designed interior glazing stop system applied inboard of the IGU, fastened to the existing window system. The completed installation resulted in a triple-glazed window, which obviously increased the energy and thermal performance of the glass. The net decrease resulted in 35 to 40 percent energy costs of what they had previously been, at 54 percent of the cost of what a tear out and replace budget might have been. While the frame performance wasn’t altered, some gain in thermal and energy performance was better than none. It was classic out-of-the-box thinking, which hopefully we’ll see more of as time goes on.

    Enough for now … next week, I’ll recap the Flat Glass and Insulating Division. Between this week and last, we’ve only made it through about half of my notes. Please holler if you have any questions about any of the topics I recapped. There are certainly people in GANA a lot smarter than me on the details of these updates (and on any and all other matters) that you can be directed to for answers.

    And, in the meantime, Blue Flu Pennant Fever has taken over Kansas City again, everyone’s going crazy and absolutely going gaga about the run the Royals are on again this year.   All I can say about Game 6 last Friday night is (to use a phrase we haven’t heard of a lot of this year): “that what speed do.” Hey, Paul Bieber, challenge accepted! Go Royals, TAKE THE CROWN!!! (Full disclosure: You’re reading this on Thursday; this is being written before Game 1 on Tuesday.)

    Tags: , ,

USGlass Magazine

USGlass Magazine