Liz's entry is not a project spec, but rather a public school district's tech guide that architects and specifiers are required to follow. So the bad spec is propagated by the owner and may be unknowingly perpetuated by the design team. Then when the contractor tries to bid or build, the RFIs will surely follow. Fortunately, Liz is an experienced Certified Construction Specifier and able to spot the problems to keep her clients out of trouble and avoid the RFI response mode.
Here are the conflicting items within the spec that Liz points out. To help identify the portions of the spec Liz discusses, the text related to each issue is highlighted with the same color.
1. Under C "Glass Products" it tells us: "Tint Color: As selected by Architect from manufacturer's full range. Review with ... District prior to final selection." But then under D "Recommended Classroom Glazing Schedule" it recommends green tinted glass.And one more that I saw, Interior Glass is specified using ASTM C1036 with the Class as scheduled. However, only the Kind (fully tempered) is scheduled. Heat strengthened glass, including tempered, is governed by ASTM C1048. Classes designate clear or tinted glass, not tempering.
2. Seeing Libbey Owens Ford as a manufacturer in a brand new owner tech guide is always fun. (Why do I say "always"? Because this is not the first hot-off-the-presses tech guide from a school district that has included it.) Wikipedia tells me the name stopped being used in 2006 when Nippon bought Pilkington.
3. Kalwall is listed as a manufacturer, too, but Kalwall doesn't make any of the types of glazing mentioned in this section.
4. D "Recommended Classroom Glazing Schedule" tells us to match GL-2, GL-3, and GL-4, but these GL's aren't defined anywhere in the tech guide.
5. C "Glass Products" tells us that "Insulating glass shall be factory double sealed units with ½" minimum air space." But D "Recommended Classroom Glazing Schedule" number 3 tells us "Overall Unit Thickness and Thickness of Each Lite: 1 inch overall (25.2 mm) and 1/4 inch exterior lite (6.0 mm) and 3/8 inch interior lite (8 mm)."
6. Class 2 designates tinted glass and Class 1 designates clear glass, but all the glass in D "Recommended Classroom Glazing Schedule" that is supposed to be tinted green is also supposed to be Class 1.
7. D "Recommended Classroom Glazing Schedule" number 3 tells us to specify that they should laminate a piece of sandblasted glass to another piece of glass, with Arctic Snow frosted PVB in between them. It seems redundant.
Liz offers the following observations. What do you think? Post your comments below.
What I'm saying is that sometimes the design professional who produces the truly horrible specs that contractors, subcontractors, and product suppliers have to deal with isn't the only one to blame. I am not saying it's not his responsibility - it is still the responsibility of the design professional to produce a good project spec, no matter what junk he's given to sort through by the owner.
The sad thing is that this school district hired an architecture firm to produce this tech guide. The architecture firm must not know enough to know it's bad. The school district doesn't know enough to know it's bad. Some of the architect consultants that the school district will hire for projects will not know enough to know it's bad. Some of the specifications consultants that some of the architects may hire may not know enough to know it's bad. It snowballs. Bad project specs get issued. Taxpayer dollars get wasted on safe enough bids to cover all the unknowns. And apparently nobody knows it's bad.
I want people to see this and take away with them the lesson that owner's tech guides aren't always correct. And despite that, the design professional is absolutely required to get the project specs correct. I have higher fees on school district projects because I know I'm going to have to wade through all this junk to get it correct, and in the process, for many school districts, I'm obligated to request permission to deviate from their tech guides. (I do - I send my justifications in writing, and they never, ever, fix their tech guides. More taxpayer dollars wasted.)
I want architects to realize that they need to independently verify every single thing in an owner's tech guide. It's their responsibility, and yes, it's absolutely a lot of extra work. I have tried to figure out how I can get the message to the school districts that their tech guides are no good, and that they keep publishing new, no good tech guides, but I haven't figured out how to communicate to them yet.