Under cover: P1 Plumbing Project Helps Secure Art for Future Generations

The terrain is uneven. The drainage is critical. The installation is challenging.And the collection is priceless.

In early 2026, an interior and exterior maintenance project began at The Nelson-Atkins Museum of Art's Bloch Building to ensure the structure protecting its art is secured for future generations.

According to Steve Waterman, Vice President and Chief Campus Officer at the Nelson-Atkins, aging roof components and other environmental factors that could lead to the damage of priceless materials prompted the need to take steps to upgrade the existing roofing system.

P1 was awarded the plumbing scope of the project by McCownGordon. The new system involves installing hundreds of feet of trench drain to ensure water that could leak into the museum is routed properly away from green roof areas.

"We are replacing original elements of the Bloch Building's green roof and making state-of-the-art advancements," Steve said. "These updates will preserve the museum's iconic architecture, ensure the art is protected, improve the guest experience, and lay a strong foundation for the future."

P1 Plumbing Foreman Clay Anderson explained how some of the museum's collections live under a green roof area, which can be vulnerable to water.

"One of the most critical updates for the buildings is replacing the original waterproofing membrane with a new, modern system that includes slot trenches installed by P1," Clay said.

Credit: The Nelson-Atkins Museum of Art in Kansas City, MO. Photographer Eric Berndt
Left: Looking from an aerial view, the upper roof on the Bloch Building is called the "Lenses". Next to it is green space where guests can walk, and which also covers parts of the museum. Right: P1 is installing approximately 426 ft. of slot trench drain, 102 ft. of grated trench drains, and 35 ft. of curved slot/trench

"The building's green roof will also get a full replacement of its soil, grass, and native plants, as well as hardscaping, using decomposed granite for some parts."

Decomposed granite, or DG, is a cost-effective alternative for asphalt or concrete, and creates softer, natural-looking walkways.

P1 was awarded the plumbing scope of the project by McCownGordon. The new system requires hundreds of feet of trench drain to ensure water that could leak into the museum is routed properly away from green roof areas.

This is done using slot and grated trench drains along with a new drainage mat under the soil and walkway bricks.

Water rolls off the mat into the trench drains and is routed to the proper drainage location to avoid sitting and seeping into the green roof.

The project included multiple partners, including Kansas City-based Sioux Chief Manufacturing.

"Sioux Chief was instrumental in making the specialty curved trench drains," Project Manager Jack Kobe explained. "Their pre-fab advice allowed our field staff to more easily make adjustments to the height of the trench drain. It also made it much easier to move the 20 ft. section of trench drains to the roof."

Clay says the varying height of the terrain across the green roof spaces presented a challenge.

"It's not a normal work site. It's somewhat treacherous terrain as it's not flat or smooth," he said.

"The layers of foam along the paths are so different in contour it's not a simple measurement, and it was difficult to anchor anything," Clay explained. "We had to learn from our first efforts to make it more successful when trying again, but we got there."

According to Kyle Meagher, Specification Sales with Sioux Chief, the main challenge was to figure out a way to get the trench drain to fit within the roof thickness above the waterproofing membrane.

"The green roof had roughly eight inches of thickness where the trench drain would need to fit," he said. "The design team was looking for a certain style slot grate that ends up being hidden along the paver walkway."

"The green roof is not flat, even though the walkway will finish mostly flat. The membrane below and the surface the channels are mounted on have a slope. Mounting the trench drain had to be adjusted before being encased in concrete," Kyle explained.

The mitered areas were another challenge.

"There are a couple sections that curve, so Sioux Chief traced it out to fabricate special curved slot drains to match them," Jack noted.

Left: Challenging terrain along the pathways and small shafts (visible to the left); Center: A look at how Sioux Chief started mapping out the potential ways to build a curve; the Nelson is reusing the angle iron holding the paver walkway together so the curved slot grate will match the curve of the existing angle iron. (photo courtesy of Sioux Chief); Right: Slot drain clean-out , the box holds the pavers and is removed for cleaning out the trench drains.

"The shallow trench drain channel, FastTrack™, is made of HDPE. After mitering the six-inch wide channels to create a curve, we welded the HDPE channels back together," Kyle said.

"The stainless steel slot grate that is hidden along the edge of the paver walkway was fabricated with a curve. The curved stainless steel slot grate then sits on the mitered six-inch-wide HDPE channels."

Jack added that some of the work also entailed tricky maneuvers into narrow shafts and manholes straight down into the building space without much room to move around.

"P1 Safety came out on multiple occasions to make sure we have the right tools, including air packs and retrieval systems," he said.

Even with the challenges, Jack says it's been a good partnership with McCownGordon and Sioux Chief. P1 has pivoted to succeed in true P1 fashion, bringing the facilities, trusted partnerships, and communities we serve to life!

QUICK FACTS:

GC: McCownGordon
Architect: BNIM
Engineers: PLAID Collaborative, SK Design Group, Structural Engineering Associates, JBC, GDS Engineering
Building Envelope Engineer: Walter P. Moore
P1 Project Manager: Jack Kobe
P1 Plumbing Foreman: Clay Anderson
426 Feet of Slot/Trench Drain
102 Feet of Grated Trench Drains
35 Feet of Curved Slot/Trench Drains specially designed for this project by Sioux Chief Manufacturing
Prefabrication of 20 ft. of trench drain sections
Est. Completion: December, 2026