Slip joint
Slip joint: a membrane layer at horizontal junctions between masonry and dissimilar materials, allowing differential movement and preventing moisture transfer.
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A slip joint is a membrane layer installed at horizontal junctions between masonry and panels or elements of different materials, such as a concrete column, steel post, or timber frame panel. Its two purposes are: (1) to allow differential movement between the dissimilar materials, typically due to different thermal expansion and moisture movement coefficients, without cracking the masonry; and (2) to prevent moisture transfer across the junction. The membrane material is typically the same type as used for a damp-proof course, such as embossed polyethylene or bitumen-impregnated material complying with AS/NZS 2904.
Slip joints are specified by the structural engineer where the junction between materials involves significant stiffness or movement differential. They differ from articulation joints (which run vertically through the masonry leaf to absorb in-plane movement) in that slip joints are horizontal membrane layers at structural interfaces.
Also known as: slip membrane, movement joint membrane.
Category: Masonry / movement / waterproofing.
Related
See also
- Articulation joint (glossary)
- Damp-proof course (glossary)
- Masonry veneer (glossary)
- AS/NZS 2904 (glossary)
Last updated: 2026-05-10. Verified: 2026-05-10.