Cleaning experts from Kärcher spent 10 days removing accumulated dirt and biological growth from Des Moines’ historic City Hall in 2017 to reveal its original limestone exterior and granite base. (Photo: Kärcher)

Mount Rushmore. St. Peter’s Square in the Vatican City. The Colossi of Memnon in Egypt.

What do these famous sites have in common with Des Moines’ City Hall?

Believe it or not, they’ve all been cleaned by Kärcher, a German-based company that manufactures high-tech cleaning gear. For the past 40 years, the Kärcher team has worked on nearly 180 historic monuments, landmarks and buildings around the world through its cultural sponsorship program.

Kärcher provided free cleaning for the colonnade at St. Peter’s Square in the Vatican City. (Photo: Kärcher).

Kärcher technicians restored the Colossi of Memnon in Egypt’s Valley of the Kings. (Photo: Kärcher)

One of the program’s leaders is a Muscatine native named Rich Barry, who studied architecture and civil engineering at Iowa State University. He’s spent the past 24 years working with America’s three largest stone monuments: Mount Rushmore, of course, plus Stone Mountain, near Atlanta, and the Crazy Horse Memorial in South Dakota’s Black Hills.

A Kärcher technician dangles from President George Washington’s nose while cleaning Mount Rushmore. (Photo: Kärcher)

He attended a National Alliance of Preservation Commissions’ conference two years ago in Mobile, Ala., and met Paula Mohr from the State Historic Preservation Office of Iowa.

Mohr invited Barry to participate in the national group’s following conference, Forum 2018, set for July 18–22 in Des Moines. She also introduced him to Des Moines city officials, who decided to bring Kärcher’s expertise to City Hall and the Police Station.

Built in 1909 and 1910, City Hall was already in the middle of a two-year rehabilitation project when Kärcher’s technicians arrived last October. After an extensive analysis, the team used steam pressure cleaners to gently remove algae, fungi, lichens and deep-seated spores without damaging the building’s limestone exterior and granite base.

“You could see the dirt (just rinse) off the building,” said Jason Van Essen, a senior planner for the city of Des Moines. “It’s nice to have that exterior work tie in with the internal work that was being done.”

In July, Kärcher’s technicians will return to Des Moines to clean the historic Police Station during Forum 2018, when Barry and his colleague from Germany, Nick Heyden, will demonstrate the tricks of their trade — specifically, how to save historic building exteriors from the damaging effects of soil and grime according to federal standards for historic preservation.

“The police station offers a unique opportunity for the attendees to see experts at work cleaning,” Van Essen said. “Most of the time you’re looking at pictures. This time, we’ll discuss it during the session and walk out to the project.”

A Kärcher technician cleans the facade of Des Moines’ City Hall in October 2017. (Photo: Kärcher)

All told, Kärcher’s donated labor on City Hall and the Police Station will save taxpayers about $80,000 in restoration costs.

“The cultural sponsoring program is something we do in the spirit of a good corporate citizen to make a difference,” program leader Barry said over the phone from the Black Hills. “It’s important to us and our customers that all this effort is focused on these historical treasures so they are preserved for future generations.”

— Jeff Morgan, Iowa Department of Cultural Affairs