Making the Grade: Mock-Up Testing Helps Ensure a Quality Project

By Ellen Rogers

Mock-up testing serves a distinct and important purpose: validating that the glazing systems will perform the way they’re designed. Not all mock-ups are the same, however. “There’s lab testing and mock-up testing and then there’s field testing,” says Mark Baker, president of IBA Consultants Inc. in Miami. “People often think they’re the same, but it’s important to highlight the fact that mock-up testing in the lab is to validate the design of the glazing or cladding system. You’re establishing that the designed-as-intended system is capable of meeting certain performance levels—air, water, structural—and that can get deeper and deeper.”

Jobsite testing, Baker says, validates the workmanship of the assembled and installed glazing products and field work.

“Some people think they don’t need one if they’re doing the other, but these tests have two very distinct and important roles.”

John Runkle, vice president of building science solutions/building and construction, with Intertek, adds, “From a quality assurance perspective, it’s hard to point to another step that’s more important than a tested mock-up. There are other important steps, but a tested mock-up is the first time to really evaluate the true performance of a project that’s specified, designed and installed by the actual technicians working on the project, using the material specified.”

He continues, “A performance mock-up should simulate the actual as-built building as much as possible; you don’t want to introduce conditions that don’t exist in real life … You also want to try and include as many systems as you can. Roof, foundation, façade, etc. … you want to have as many of those interfaces on the mock-up.”

When to Do a Mock-Up

While some types of testing can occur during construction, performance mockups are done before that begins.

“Sometimes the owner will require it, especially on high-end healthcare, institutional or university projects,” says Tony Cinnamon, associate principal at Wiss, Janey, Elstner in Chicago. “Architects will often define in the spec what test procedures [they want] for that mock-up. Air, water, structural—those are baseline, but then you can get into vertical and horizontal movement, thermal testing, dynamic water testing, etc., and all of that is typically in the spec.”

It wasn’t that long ago that mock-ups were mostly done on high-end, custom
jobs. That’s changed a lot.

“They aren’t necessarily just for $100 million projects; we also see them on $15-20 million projects,” says Runkle.

Baker adds that full-scale mock-up testing is critical on custom systems that have never been manufactured or built.

“If it’s a one-of-kind system, it’s absolutely critical that performance testing is done, because that will confirm the system is capable of meeting the required criteria. It’s necessary and worth the investment,” he says.

On the other hand, Baker says that mass produced/off-the-shelf systems have already been tested and validated. He adds, though, that as manufacturers refine their systems over time and material changes are made then they would require a mock-up.

There’s also an exception to the rule. “If a typical system will be used in a unique or complicated way, we sometimes will recommend a mock-up,” says Baker.

Visual Mock-Ups

Some projects may also call for a visual mock-up. According to Cinnamon, a mockup that’s for visual purposes only is infrequent.

“There are a few cases in larger projects where there will be a separate visual mockup, and a lot of times that’s for the glass,” says Cinnamon. “Color-wise, you can see if there are any issues and how it will look together. These are done early on in the project.” He says the visual mock-up can also establish glass flatness, such as roller-wave distortion, anisotropy, etc.

Design Assurance

Performance mock-ups are an essential step to ensuring the building will perform as it’s intended, and can help save both time and money. However, in some cases mock-ups will be value-engineered out.

“We tell our clients [having a mock-up is] in their best interest because it can solve a lot of problems later on,” Cinnamon says. “This is not where you want to cut costs.”

“Embrace the concept, because if a design is flawed, the sooner you find out the better you can save money and cause less headaches,” adds Baker.

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