Wall tie
A wall tie connects the outer brick leaf to the inner leaf or stud frame. Type and spacing under AS 3700 and NCC Part 5.6 by wind class. Light, medium, heavy duty.
Ask Chalkline about this →A wall tie is a metal or polymer connector that bridges a cavity in masonry construction, mechanically linking the outer leaf (the visible brick or block) to the inner structural element (a second masonry leaf in cavity construction, or a timber or steel stud frame in brick veneer). The tie transfers lateral wind load from the outer leaf to the inner backup while allowing limited differential movement between the two leaves.
Type and material under AS/NZS 2699.1:
| Duty | Where to use | Common materials |
|---|---|---|
| Light duty | Wind class N1 and N2 (most inland and low-wind metro builds). | Hot-dip-galvanised steel, polymer (some areas). |
| Medium duty | Wind class N3 (most coastal and exposed metro builds). | Heavier-gauge HDG steel, stainless 304. |
| Heavy duty | Wind class N4, C1, and above (cyclonic regions, coastal exposure). | Stainless 316, heavy-gauge HDG. |
Material grade matters with exposure. In coastal or saline locations, stainless steel ties are mandatory because galvanised ties corrode within 5 to 15 years in marine atmosphere. The corrosion failure is invisible from outside; the first sign is brick veneer leaning out or coming away from the frame.
Spacing under NCC 2022 Housing Provisions Part 5.6.
- Brick veneer to timber/steel frame: typical spacing is 600 mm vertically × 600 mm horizontally for N1/N2 walls; tighter at openings, corners, and articulation joints.
- Cavity masonry: similar spacing in the body of the wall, with extra ties at openings (jambs, sills, lintels).
- At openings: typically 1 tie per 300 mm of opening jamb height within 200 mm of the opening edge.
- At control joints: paired ties either side of the joint.
Fixing on brick veneer:
- Timber frame: the tie has a fold-out or screw-fix arm that nails or screws into the stud face. A flexible knuckle accommodates differential movement.
- Steel frame: clip-on or self-drilling tie variants.
- Masonry cavity: the tie is laid into the mortar bed joints on both sides of the cavity. Embedment minimum 50 mm into mortar.
Common defects:
- Missed ties at openings (jamb stack and lintel-bearing): the most common cause of veneer cracking around windows after wind events.
- Bent ties when stacking bricks before mortar sets: the cured tie has a permanent kink and reduced load capacity.
- Reverse-slope drip: ties laid sloping inward toward the cavity collect water and corrode faster. The drip should slope outward (away from the frame) so water sheds.
- Wrong material in coastal exposure: HDG ties used within 1 km of surf where stainless is required. Discovered when the brick leaf starts moving 10 years later; rectification means re-tying through the wall.
For builders. Confirm the wind class for the lot at quote stage. The frame designer specifies the tie type on the structural drawings; the brickie carries them out. Sight ties laid into bed joints at the brickwork-frame interface during framing inspection; missing ties at this stage are still cheap to remediate.
Also known as: brick tie, cavity tie, veneer tie.
Category: Materials / masonry / fixings.
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Last updated: 2026-05-14. Verified: 2026-05-14.