Bloomfield, New Jersey
finished deck coating

Parette Somjen Architects reached out to Sika to seek a solution to waterproof the split slab deck at Demarest Elementary School. The existing waterproofing system between the two decks failed, and it leaked for decades into the unused coal cellar. With a re-functioning and modernization of the coal tar cellar, a reliable waterproofing system was important to prevent leakage and consequential damages in the new construction.

deck before repair
waterproofing system
deck in progress


The Sikalastic RoofPro 20 system has been evaluated as the best option, as its unique features addressed all critical points. Movement joints and cracks were sealed and waterproofed with Sika Flexitape Heavy at the early phase before winter to protect the structure from further water ingress during the cold months. The final Sikalastic RoofPro 20 was installed the following spring with slip resistance finish that allows direct pedestrian traffic. Together with the installer, Sika provided a 20 year single source NDL warranty for the installed system.


  • Engineer: Parette Somjen Architects, NJ
  • General Contractor: Drill Construction, West Orange, NJ
  • Contractor: East Coast Masonry, NJ