Koster KSK SY 15 consists of a highly tear resistant, 2-layer cross laminated polyethylene foil with a plastic bitumen / rubber adhesive and sealing compound. It is cold applied and therefore no hot air or propane gas welding is required for application. Due to its high ductility it can easily be applied to difficult details. The sealing membrane is highly flexible, immediately waterproof, resistant to driving rain, and crack bridging. Koster KSK SY 15 is also radon proof.