Burt Olhiser – June 21, 2012
The following is the first installment of a two-part discussion of a number of failure-analysis projects that involve an industry standard that itself has failed to some degree, though perhaps through no fault of the intent of the standard or the undoubted good intentions of its authors.
In reality, the blame has to be assigned in part to materials that have changed since the guidance document’s origination some 20-plus years ago. Other factors also are at play, which we’ll get to shortly.
These projects are of interest because they all had one common denominator: the finishes specified for the drywall system were “smooth wall” or “Level IV” finishes.
I should add right at the start that the opinions expressed here are not just my own, but are shared by another coating consultant whom I have previously worked alongside and for whom I have the utmost respect, but who must, for now anyway, remain anonymous.
To understand this fully we must go back to 1990, when the Association of Wall and Ceiling Industries International (AWCI), the Ceilings and Interior Systems Construction Association (CISCA), the Gypsum Association (GA), and the Painting and Decorating Contractors of America (PDCA), presented a consensus document, “Levels of Gypsum Board Finish.”
There was considerable confusion at that time in the industry, which was why this document was necessary in providing a precise description of the desired finish of walls and ceilings prior to final decoration.
Paint failures and finger-pointing
Over the past seven to eight years this author and other contributors of information for the discussion I offer here have seen an increase in the number of paint-failure complaints involving drywall. The problems generally arise during the construction phase when outlet penetrations or other modifications are being made to the wall system. In other cases, so-called “coating failures” occur when painters’ tape (blue and others) is applied and then removed from a painted wall, pulling the paint off with it.
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Photo courtesy of CertainTeed |
| High-level visuals: Level 4 and Level 5 drywall finishing methods produce appearance qualities prized by architects, designers and owners. |
Historically, when such problems have been investigated, an outbreak of finger-pointing ensues between the drywall contractor and the painter. The drywall contractor, with the assistance of the joint-compound manufacturer, usually claims that the painter (1) did not properly dust the walls off prior to painting, (2) omitted the primer, (3) used the wrong primer, and (4) did not apply enough paint. The painter generally counters with a frank statement that the joint compound seemed “funny.”
After a period of high-decibel yelling and screaming and generally with only a small amount of forensic work performed on the failure, an agreement is generally reached, the walls are touched up and the project is turned over to the owner. Frequently, this resolution is acceptable, since once the project is completed, very little stress (like what occurs when applying and removing tape) is imposed on the wall system and so the walls serve their function.
While the exact reason for this uptick in the frequency of failures is not totally understood, I believe it can be attributed to a number of different changes in the drywall construction industry that include:
1. a change in the demographics of the drywall industry,
2. a change in the formulation of joint compound, and
3. wider use of the relatively new standards for drywall finishing.
With this discussion, we endeavor to examine the impacts of these industry changes on drywall systems and failure reports, and review a vast forensic investigation of the problem, carried out recently at a large university dormitory complex in California.
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Photo by Emilio Collavino; courtesy of New World Center |
| A view of the atrium of the New World Center in Miami, designed by Frank Gehry. |
The forensic evidence is supported by identical findings at other large projects, including a 600-unit condo job in San Francisco, on plaster walls at a prison, and other lower-profile locations that the author has been involved with in one way or another. We are excluding specific details of these lower-profile projects at the request of the property owners.
Changes in drywall ‘demographics’ and the industry
For many years the drywall industry was populated by crafts people who received much of their training in the plastering industry prior to large-scale use of gypsum-board (drywall) construction. The application of plaster required much more skill than drywall finishing, and plasterers developed their craft into an art form.
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Gypsum Association |
| GA 214, Recommended Levels of Gypsum Board Finish, offers details on these various finishes along with the requirements for each. |
The author has also been involved in some plaster failures over the years, and has observed the difference in skill levels between the “old timers” and younger plaster applicators. One experience involved a recent project where a curved plaster wall was being erected. To create this wall, it was necessary to summon a specialty plastering firm of European-trained professionals to finish the job, because the young local plasterers did not possess the requisite skills to do so.
In concert with the change in crafts people and their training, changes in the makeup of the plaster/drywall manufacturing companies has occurred. Small manufacturers were absorbed by major corporations that now control the majority of the market. The result of this consolidation was greater emphasis on production and profit margins. This, in turn, led to the development of products that promised application shortcuts to add speed and ease to the drywall process. The product feature most germane to the discussion here was the development of “easy sanding” toping “muds.”
Finally, industry groups developed standards that encouraged the use of these new materials to create various gypsum-board finishes. Specifically, the Association of Wall and Ceiling Industry (AWCI), the Gypsum Association, the Ceiling and Interior Systems Construction Association (CISCA), and the Painting and Decorators Contractors of America (PDCA) in 1990 developed, GA-214-90, Recommended Levels of Gypsum Board Finish.
The document offers details on these various finishes along with the requirements for each. Of particular interest are the Level 4 and 5 finishes, which are essentially the same except that a Level 5 finish requires a final skim coating of the entire gypsum-board surface with a joint-compound material. Level 4 and 5 finishes, commonly known as “smooth-wall” treatments, have been greeted with enthusiasm by many architects because these finishes are able to produce a wall very near in appearance to plaster.
Since their introduction the popularity of these finish systems has grown, and are used widely.
Unfortunately, however, this has led to the drywall painting problems that are the subject of this two-part discussion.
In addition to specifying levels of finish, recommendations were included in the GA-214 standard for the application of a drywall primer that was to be applied directly to the finished gypsum board prior to the application of the paint system. The document, however, does not define what a drywall primer is. This has frequently sparked an argument, with the drywall industry stating that the material is a high-solids primer to be used where final appearance is critical, where it helps minimize appearance issues in final decorating.
The painting industry’s reply is that the material is a low-solids, low-cost primer/sealer known as a PVA product (based on polyvinyl acetate resin). Needless to say, it has been the author’s experience that considerable confusion exists in the industry regarding these conflicting interpretations.
So with all of these industry improvements, how then could there be an increase in the number of failures on painted drywall. We’ll attempt an explanation in the second installment of this discussion.