The KERDI-KERS is a pre-formed foam corner seal for KERDI waterproofing — it fills the 90° angle at inside corners (wall-to-wall, wall-to-floor) before the KERDI membrane goes over it, creating a stronger, more reliable corner waterproof seal.

Unlike the flat KERDI-KERECK corner pieces that just bridge the angle, the KERDI-KERS actually fills the corner with a triangular foam strip. This prevents the KERDI membrane from bridging air space at the corner, which is the #1 cause of membrane damage at inside corners during tile installation.

• Pre-formed foam corner seal for KERDI inside corners
• Fills the 90° angle so KERDI membrane has full mortar support
• Prevents air bridging — the most common cause of corner membrane failure
• KERDI membrane and KERDI-BAND go OVER the KERS after installation

Pro Tip: This is the upgrade most DIYers miss. When KERDI spans an inside corner without backing, pressing tile into the corner during installation can push through and puncture the membrane. KERDI-KERS eliminates that risk. If you're doing your own shower, add these to your order.