Problems with Gypsum Association systems

Almost every set of drawings I look at has discontinued GA systems indicated as wall types. I point this out to the architect and have them select new systems. Even more problems arise when they select systems that are proprietary from different manufacturers. Contractors are going to buy and install products from one manufacturer. I strongly encourage them to pick generic systems, though specialized systems, such as shaft walls, are always proprietary.

How have you handled these issues? Has a building official/inspector ever caught an issue with a gypsum board product being installed that is different from the product noted in the system?

FYI, the latest Fire Resistance Design Manual (GA-600) is the 21st edition 2015. You can order the handbook here https://www.gypsum.org though I usually get mine free from product representatives.

I have scanned discontinued listings from the latest (2015) and previous editions (2012 and 2009). If you send me an email I will sent this scan to you. David (at) AxtConsulting (dot) com

OSHPD is hip to this, and doesnt generally allow the proprietary detail unless its a field revision accompanied by a matching product submittal from the contractor.

One way I try to mitigate this in my office is via training, and showing our younger staff how Table 7C allows adoption is the GA manual as if it was Code, but only for generic assemblies as stated in the Table footnotes.

We had a similar issues with shaftwall because some shaftwall manufacturer’s are more lenient with what direction you can install each layer than others. The installed manufacturer didn’t have anything in writing to back up the actual installed method causing headaches for everyone.

Personally, I have never found the GA Assemblies helpful.

Nathan,

What is Table 7C? Thanks.

David, Chapter 7 of the UBC has tables of listed fire rated assemblies. Table 7C is for walls/partitions. On rare occasions Ill need a non-standard assembly and the AHJ allow the adoption/use of non-proprietary assemblies from the GA manual because its Code!

UBC? What jurisdiction still uses the UBC?

Although the IBC allows the use of “GENERIC” assemblies from GA-600, I always tell people if they want one of the assemblies marked “PROPRIETARY,” then look to see if it has a UL assembly number and then look that up in the UL directory–AHJs have no problem with UL assemblies.

Also, just because GA has published a new manual does not mean it is acceptable. The 2015 IBC references the 2009 GA-600. If the 2018 IBC is adopted, then you can use the 2015 GA-600. AHJs may allow you to use the most current edition, but ask before relying on it.

Yes yes, IBC, not UBC. I was trying hard not to say CBC (Californa Bldg Code), and got the Model Code reference wrong. It happens.

Nathan,

Actually you meant to say “UBC Table 7C”.

In 2015 International Building Code the tables are now:

Table 721.1(1) Minimum Protection of Structural Parts Based on Time Periods for Various Noncombustible Insulating Materials, footnote m.

Table 721.1(2) Rated-Fire Resistance Periods for Various Walls and Partitions, footnote o.

Table 721.1(3) Minimum Protection for Floor and Roof Systems, footnote q.

Those footnotes read as follows:

“Generic fire-resistance ratings (those not designated as PROPRIETARY in the listing) in the GA 600 shall be accepted as if herein listed.”