Installation details may explain Lincoln Memorial Reflecting Pool problems

Investigative Photojournalist

WASHINGTON —

A $14 million taxpayer mystery has been unfolding at the Lincoln Memorial Reflecting Pool, as questions continue to grow over why its newly installed waterproof coating is already peeling.

President Donald Trump has blamed vandals with knives, which has resulted in criminal investigations, while a former Olympian was indicted Thursday for allegedly using his hands to forcefully cause damage. Others have suggested hydrogen peroxide used to combat algae damaged the coating. Some questioned whether the presidential motorcade that crossed the pool after construction caused the failures, while others argued the waterproofing material itself was the wrong product.

Hearst Television’s National Investigative Unit asked two waterproofing experts to review project documents, contract specifications, photographs and video from the project.

Kyle Flanagan, president and founder of Freedom Chemical Corp., and Aidan Bradley, the company’s vice president and co-owner, have nearly 60 years of combined experience designing, developing and installing the same material used during the reflecting pool’s recent renovation.

Their opinions are based solely on the material they reviewed. Both experts arrived at many of the same conclusions.

The coating isn’t paint

One of the biggest misconceptions surrounding the reflecting pool is what visitors are actually seeing floating in the water.

“What people are calling paint chips are not paint,” Flanagan said.

The material is a spray polyurea — or spray polyurea hybrid — a specialized waterproof coating designed to protect concrete that remains underwater.

Unlike ordinary paint, this coating is about one-eighth of an inch thick, making it far more durable than a typical coat of paint.

“They’re thick-film elastomeric coatings,” Flanagan said.

Bradley said polyurea has become a trusted waterproofing material because it cures quickly, remains flexible and has been successfully used for decades in fountains, reflecting pools and other water features.

“The technology is absolutely the right technology to choose,” Bradley said.

Reflecting pool renovation timeline

The material itself may not be the problem

Because sections of the polyurea have detached from the pool floor, some have questioned whether the wrong product was used.

Neither expert believes that’s the case.

“Absolutely not,” Flanagan said when asked whether polyurea was the wrong choice for the project.

He said similar coatings have remained in service for nearly two decades on other projects, demonstrating that the product itself has a long track record when installed correctly.

“There are lots of polyureas out there,” Bradley said. “Different types, different elongation, different cure times.”

“But the technology is absolutely the right technology to choose.”

The experts also rejected the idea that using a hybrid polyurea rather than a pure polyurea caused the failures.

“I don’t think it’s the product selection here,” Flanagan said.

Bradley pointed to a job he did at New York City’s Lincoln Center roughly 16 years ago that used a polyurea hybrid. He said it continues to perform successfully.

Where the experts focused their attention

Instead of focusing on the coating itself, both experts zeroed in on how it was installed.

Based on the photographs and video they reviewed, neither expert saw signs that the coating was separating from the concrete underneath it.

“There doesn’t seem to be a problem with surface preparation and coating coming up from the concrete,” Flanagan said. “So far what we see are tie-in detail problems where there’s some lifting and potentially some issues at the expansion joints.”

Why tie-ins could be important

Projects the size of the Lincoln Memorial Reflecting Pool are not sprayed in a single day.

Instead, contractors complete the work in sections, creating what the industry calls “tie-ins” — locations where one day’s work meets the next, creating a seam.

Those seams have to be completed within about six hours so the new coating properly bonds to the previous day’s work. If too much time passes, installers have to prepare the surface before applying more material.

Based on the photographs, Bradley said some of those tie-ins appear to have been feather-edged — gradually sprayed thinner near the seam, likely to hide the transition from one day’s work to the next.

“The reason they do that is to hide that line,” Flanagan said. “It becomes an aesthetic thing.”

While spraying the coating thinner at the edges may improve its appearance, both experts said it can create problems in underwater applications.

“We don’t advocate feather edging,” Bradley said. “You want to keep that thickness all the time.”

If installers returned after the recommended six-hour window without properly preparing the existing coating, Bradley said the two layers may not stick together properly.

“If you don’t do that, it’s not gonna stick,” he said. “Which is why you might be seeing this flapping effect and people lifting up the feathering.”

Flanagan said some of the peeled pieces appear thin enough to see light through.

“If I can see through it,” he said, “that means it’s not at the proper thickness.”

Questions remain about the expansion joints

The second area both experts highlighted involves the pool’s expansion joints.

Expansion joints are built into large concrete structures so they can naturally expand and contract as temperatures change throughout the year.

Based on the photographs they reviewed, Bradley said it appears the joints may have been sprayed over, although he cautioned that the images alone are not enough to confirm that.

“It looks like it,” Bradley said, “but we can’t be definitive.”

If the joints were coated directly, Flanagan said repeated movement could eventually crack the waterproof coating.

“It’s going to crack,” he said. “It’s going to let water into the joint, and it’s going to let water underneath the polyurea.”

Once that happens, the experts say the reflecting pool could begin leaking.

Bradley said the full effects might not become apparent until the pool experiences a complete cycle of seasonal temperature changes.

“You need to go through 12 months of extreme heat and extreme cold,” he said. “Then you’ll have a better idea.”

Debunking several popular theories

Several explanations for the peeling coating have circulated publicly. Based on the information they reviewed, the experts said many are unlikely.

Hydrogen peroxide

Both experts said hydrogen peroxide used to treat algae is unlikely to explain why the coating began peeling so quickly.

While highly concentrated chemicals should never be poured directly onto any waterproof coating, Flanagan said hydrogen peroxide would quickly mix with the large volume of water in the reflecting pool.

“It’s unlikely,” he said, explaining that if the chemical were going to damage the coating, it would most likely happen gradually over time — not almost overnight.

The presidential motorcade

Bradley also dismissed speculation that the presidential motorcade damaged the coating.

He said this type of waterproof coating is commonly used beneath bridges and roadways designed to support traffic much heavier than presidential vehicles.

“The only caveat,” Bradley said, would be if a heavy vehicle crossed directly over a soft expansion joint. “But even then I’d say it’s unlikely.”

Vandalism

President Trump has suggested vandals armed with knives damaged the pool.

Bradley said someone with a knife could damage a small area if the coating was stretched over an expansion joint where there was open space underneath.

However, he said cutting through coating that is firmly attached to concrete would be extremely difficult.

“You could localize it,” Bradley said. “But where the polyurea is bonded to concrete, that’d be very difficult to do.”

Looking ahead

The National Park Service has said the reflecting pool will be drained after Fourth of July festivities so crews can make repairs.

Both experts said that will provide the first real opportunity to inspect the areas they identified and determine whether installation details contributed to the peeling coating.

If they were inspecting the project themselves, both said they would begin with the tie-ins and expansion joints.

Flanagan said repairs would likely begin by removing loose sections of the coating before cleaning and preparing the remaining surface and carefully applying new material.

Bradley said his company also routinely requires an independent third-party inspector on projects. While he said that is not an industry standard, he believes it provides an extra layer of quality control by identifying small issues before they become larger issues.

For both experts, the problems appear to reinforce a simple point: even the best products rely on proper installation.

“The devil’s in the details,” Bradley said. “There’s obviously a couple of things here that have gone amiss.”

Hearst’s National Investigative Unit requested comment from the contractor that performed the waterproofing work on the reflecting pool. The company has not responded.