Description
Our Bar Chairs (frequently referred to as rebar spacers, mesh supports, or concrete chairs) are essential structural accessories designed to elevate reinforcing bar (rebar) and steel mesh during concrete placement. Maintaining exact concrete cover, the depth of concrete surrounding embedded steel, is a fundamental requirement in residential, commercial, and civil construction.
Without proper clearance, exposed or poorly positioned steel reinforcement is vulnerable to moisture ingress, leading to concrete cancer, structural cracking, and long-term failure. Installing durable, high-density plastic bar chairs guarantees that your reinforcement sits precisely where engineered, protecting your investment and ensuring full compliance with Australian Building Standards (AS 3600 and AS 2870).
Key Features & Operational Benefits
- Secure Clip-On Locking System: Features a specialized top clip that snaps directly onto rebar or trench mesh wire. This tight fit prevents reinforcement from shifting, sliding, or dislodging during intensive concrete pours, heavy foot traffic, or mechanical vibration.
- Dual-Height Versatility: Engineered with a reversible design offering two cover heights per unit (e.g., flip between 25mm and 40mm). This dual functionality simplifies site ordering, reduces material waste, and gives builders immediate flexibility on-site for varying slab depths.
- Heavy-Duty Construction: Manufactured from high-impact, non-corrosive plastic designed to withstand high point-loads without bending, cracking, or collapsing under heavy reinforcement mesh or worker weight.
- Corrosion & Rustproof Guarantee: Unlike metal supports that can rust over time and bleed through the slab surface, plastic chairs remain inert inside cured concrete, ensuring a clean finish and rust-free durability.
- Broad Surface Base: Designed with wide stable feet to distribute weight evenly, preventing the chairs from sinking into sand, crushed rock, or plastic vapor barriers beneath the slab.
Available Cover Heights & Sizing Options
- We stock a full range of dual-height plastic bar chairs to suit various slab thicknesses and engineering specifications:
- 25mm / 40mm Bar Chairs: Standard choice for thin slabs, residential footings, driveways, and garden pathways.
- 40mm / 50mm Bar Chairs: Common for suspended slabs, reinforced driveways, and light commercial ground slabs.
- 50mm / 65mm Bar Chairs: Suitable for heavy vehicle driveways, commercial foundations, and industrial floors.
- 75mm / 90mm Bar Chairs: Ideal for deep footings, heavy structural slabs, and civil engineering projects.
- 85mm / 100mm Bar Chairs: Designed for high-cover structural elements, retaining walls, and mass concrete placements.
Applications & Ideal Uses
- Plastic bar chairs are suitable for a wide variety of concreting applications:
- Residential house slabs, strip footings, and waffle pods
- Concrete driveways, crossovers, pathways, and patios
- Precast concrete panels, tilt-slab constructions, and retaining walls
- Swimming pool concrete shells and civil infrastructure projects
- Works seamlessly with SL62, SL72, SL82 reinforcing mesh, and N12/N16 rebar bars
Installation Guidelines
- Prepare the Sub-Base: Ensure your crushed rock, sand, or moisture membrane (under-slab plastic sheeting) is level and compacted prior to placing reinforcement.
- Space Correctly: Position bar chairs in a grid pattern under the reinforcing mesh or rebar. For optimal support, space chairs approximately 700mm to 1000mm apart (or roughly 1 to 1.5 chairs per square meter) to eliminate sag.
- Clip into Place: Align the mesh wire or rebar with the clip head at the desired height setting and push down firmly until it snaps into position.
- Inspect Before Pouring: Walk the slab prior to pouring concrete to verify that no chairs have been knocked over or dislodged during steel fixing.
