​WS Block Filler

A one-component, water-based block filler based on Silica Fortified Rubber™ chemistry. WS BLOCK FILLER is specifically designed for use with BASF air/water-resistive barrier products.


WS BLOCK FILLER is designed to prepare rough, porous concrete / masonry substrates for subsequent application of BASF fluid applied air/water-resistive barrier products.
WS BLOCK FILLER is also designed to promote adhesion of BASF WS FLASH self-adhesive membrane to rough CMU surfaces. It can be used to create tight, seamless expansion joints and to facilitate adhesion of through wall flashing systems.