Iconic Danish bathing facility under attack by shipworms

The historic “Den Permanente” bathing complex in Aarhus, renovated just years ago at a cost of 60 million kroner, is already being damaged by shipworms, reports Danish broadcaster DR.

Bo Kræmer, chair of the Jomsborg winter bathing club, discovered the infestation in March while inspecting the wooden support structures. “I was horrified,” he told DR. “Our contractors promised the materials would last 25 to 50 years, so it’s shocking to see damage already—some beams have lost centimeters of wood.”

The facility, co-owned by Jomsborg (with 11,000 members) and Aarhus Municipality, underwent a 19 million kroner municipal renovation in 2019, followed by a 42 million kroner club-funded expansion in 2024. Now, both parties are assessing the extent of the damage.

Nicolaj Kiilerich, head of property management for Aarhus Municipality, confirmed the issue is progressing faster than expected. “Our initial reaction was frustration,” he said. “The piles were supposed to last over 40 years.” While early assessments suggest no immediate safety risk, officials are evaluating long-term structural and financial impacts.

Kræmer warned that shipworms—known for relentlessly consuming wood—could eventually compromise the structure’s integrity. “They never stop eating,” he said. “If the wood loses strength, we’ll have a serious problem.” Potential solutions may require costly replacements, including removing cabins, decks, and pilings, with possible temporary closures for members.

The bathing complex, originally built in 1933, is a landmark in Risskov, Aarhus.