Everyone has seen paint peeling off a surface like layers off an onion. Are you taking the steps to ensure this problem won’t leave you weeping?
Bob Cusumano, president of Coatings Consultants Inc. in Palm Beach Gardens, FL, has encountered many horror stories involving painting and coating failures. In some cases, these can cost building owners and facilities management professionals thousands of dollars. In extreme cases, they can cost folks their jobs.
Two building areas that can be particularly troublesome are exterior facades and exposed ceilings.
Cusumano was called in to determine why the heavy-duty textured coating on the exterior walls of a tilt-up concrete warehouse was failing. After performing 300 adhesion tests, he discovered the reason.
“The concrete was too hard and slick so no mechanical adhesion was obtained,” Cusumano says, adding that all sealants and primers had to be stripped. “It was a much more difficult situation than just doing it right the first time. The painting contractor went out of business over this.”
If the surface had been properly analyzed, prepared, and tested beforehand, Cusumano noted, the problem could have been sidestepped.
Painting professionals stress the importance of utilizing experts to avoid these issues before they happen. Remedial action can be much more expensive and time-consuming, says Karl Schmitt, vice president of research and design at Sherwin-Williams.
“The very, very best process is prevention,” Schmitt says. “When people are doing a painting project, they think about the color, the finished look, or the painting process. But, far and away, the most important part of a sound painting process is proper surface preparation.”
Analyze the Substrate
Preparation begins with study of the surface and how the coating adheres, says Cusumano.
“You need to have that specified well enough in order to get the result you need for longevity. Then do a benchmark sample,” Cusumano added. “Take a small area of the building, and do your surface prep, apply your coatings, allow them to cure, and then do adhesion tests.”
There are a variety of tests Cusumano conducts to determine what materials and application techniques should be used to ensure long-lasting results. If these tests had been performed in one case he saw, it could have saved thousands of dollars.
A new high school gymnasium in a Midwestern community featured interior exposed galvanized metal ceilings, structural steel, ductwork, and piping that were to be painted. Most of this metal was pre-treated to prevent corrosion.
Unfortunately, that treatment can interfere with paint adhesion, Cusumano notes, adding that testing can determine if the treatment is present and whether a special primer should be used.
However, the project team skipped these essential steps.
“The paint was just hanging off like cobwebs,” Cusumano says. “Sometimes when you attempt to save yourself a few dollars, you may cost yourself thousands.”
Execute the Plan
If a team is approaching a project that involves painting an entire building with a variety of surfaces, Schmitt and Cusumano agree that specialists and consultants can offer step-by-step guidance to complete the job. Cusumano’s checklist analyzes the current condition, including existing coatings.
“Many times you see an existing coating that is mostly fine without widespread peeling,” he says, “but when you put on additional coats, the added weight and stress cause delamination. The new coatings adhere to the existing coatings, and they start to lose their adhesion.”
Cusumano’s process also includes repairing or replacing any deteriorated substrate, determining the necessary primer, and using finish systems that provide the service life sought.
“People ask, ‘What’s the best paint?’ There’s no one answer to that,” he says. “You’re looking for different results on different substrates. Ensure the paint system is compatible with the intended use of that surface.”
For example, to avoid discoloration due to exterior leaching, the primary substrate and surrounding structures may require different primers, coatings, and sealants. A careful, professional method should be used.
“People think that anybody can paint. Everybody has painted his or her grandmother’s bedroom or the outside of her house,” Cusumano explains. “I’ve seen large-scale coatings failures with this approach.”
Chris Curtland (firstname.lastname@example.org) is assistant editor of BUILDINGS.