Roof of the world’s deepest diving pool waterproofed with UltraPly TPO

The Deepspot scuba diving pool, located about 50 km from Warsaw (Poland), is currently the world’s deepest multi-zone diving pool, with a depth of 45.4 m. The pool contains 8,000 m³ of water, which is as much as 3 and a half Olympic swimming pools. The water is kept at 32-34 °C, providing perfect diving conditions. Open to the public since December 2020, Deepspot welcomes divers of all levels.

Project ID

Mszczonów, Poland

Project type

New build

Building type

Recreational building


1,400 m² TPO + 800 m² EPDM


Elevate UltraPly TPO 1.5 mm (gray) + Elevate RubberGard EPDM 1.1 mm


Mechanically attached

Construction works for the main building housing the diving pool started back in 2018 and roofing works began in January 2020. Because of the high humidity levels inside the pool, vapor resistance was a critical requirement for the roof. Elevate’s V-Gard vapor control layer was installed on the corrugated steel roof deck, followed by PIR insulation boards. About 1,400 m² of Elevate’s 1. 5 mm thick, gray UltraPly TPO roofing membrane were mechanically attached on top of the thermal insulation layer using stainless steel fasteners, which provide better resistance to humidity. In addition, each fastener was covered from the bottom and secured with an Ejot tread protection sleeve to further minimize vapor transmission through the roofing system.

The section of the roof above the lockers, showers, offices and reception desk consisted of a concrete deck covered with a PE vapor control layer, followed by EPS insulation boards and about 800 m² of Elevate’s 1.1 mm RubberGard EPDM waterproofing membrane, secured in place using ballast.