Arch Waterproofing Project

     The Gateway Arch is one of the most recognizable landmark in the country and is one the first images people associate with the city. In 2009 the city decided to make the river front more welcoming, lively and more connected to the downtown area. This direction evolved into a design that will create a seamless connection between the city, the Arch and river.

    A key aspect to this connection between the Arch and City re‐ quires adding a large concrete deck that will span over the high‐ way that presently stands between the two areas. This concrete deck requires a waterproofing system to protect the concrete from water seepage and premature deterioration. Once the waterproofing is applied soil will be added for grass and various landscaping.

     CREATIVE POLYMERS, a St. Louis based manufacturer of epoxy, polyurethane and polyurea coatings and systems, was awarded the contract to supply a specialize Polyurea waterproofing elastomer system. The Geo‐Tek 4950 polyurea system can be applied easily to 100 mils with high tech plural component equipment and cures in less than 15 seconds. This high performance elastomer is a tough and highly flexible system that as a result of the fast cure properties has minimum interruptions to the overall project and a allows a quick turnaround to the next construction stage.



Recap of the system used on this project  


Concrete deck in‐stalled ST. LOUIS ARCH BRIDGE DECK SPECIFICATION UREPRIME 1305: polyurethane primer ‐ designed to cure at lower temperatures and provide beƩer intercoat adhesion between fast set polyureas and polyurethanes. Also, designed to provide adhesions to aged epoxy, polyurethane and poly‐urea substrates.

GEO-Tek 4950: Polyurea system designed as a fast cure system that is tolerant of low temperatures an high moisture.


PLIA-THANE 4975: 2:1 ratio medium cure polyurethane system. A geotextile was incorporated into this system for extra protection to the waterporoofing system during the landscaping progress