Bond breaker
A bond breaker is a material applied at movement joints in wet areas to allow independent substrate movement without tearing the waterproofing membrane.
Ask Chalkline about this →A bond breaker is a flexible material applied at structural junctions (wall-to-wall, wall-to-floor, hob-to-wall) before the waterproofing membrane is applied. It prevents the membrane bonding directly to the substrate at these joints, allowing each substrate to move independently without tearing the membrane.
Bond breakers are mandatory at all wall-to-wall, wall-to-floor, hob-to-wall junctions, and movement joints for bonded membranes in wet areas under NCC 2022 Housing Provisions Part 10.2.27. The material must be compatible with the flexibility class of the membrane as classified under AS/NZS 4858:2004 (R2020). Incompatible combinations cause membrane failure at the joint.
Common failure mode: bond breaker omitted or incompatible product used. Identified at PCI by diagonal tile cracking from junction corners.
Also known as: bond breaking tape, joint filler.
Category: Wet areas.
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Last updated: 2026-05-08. Verified: 2026-05-08. Quarterly review for currency.