Willseal Coreseal is a preformed, compressible system that is impermeable to water and when bonded in place provides a watertight seal. It was developed to meet all applicable standards for compressible sealants and performs under extreme conditions such as those found in vertical and horizontal applications including bridge and parking structure type expansion joints. It provides a watertight, dust-proof, airtight, UV stable, chemically resistant, soundproof, and insulated primary seal. Once installed in the joint, the material adapts to the width of the joint and the irregularities of the substrate, provided such profile changes are not sudden or extreme.