Select the chair height to match the required concrete cover and slab thickness, not just the rebar diameter. Matkel offers options for thin slabs, thick slabs, and heavy-traffic floors, helping maintain proper rebar position and reducing cracking under high Saudi heat.
Choose engineered plastic or metal chairs rated for the slab density and leveling speed. Proper spacers should resist wet concrete pressure without bending, sinking, or breaking. Placing them at regular intervals helps prevent rebar drop and surface cracking after the slab cures.
Spacing depends on the structural element, slab or wall thickness, and rebar bar size. As a practical rule, chairs should contact every rebar line with no unsupported gaps. Use closer spacing in thin walls, narrow columns, or limited cover areas to support load distribution and maintain required concrete cover.
Quality concrete chairs are made from materials resistant to cement chemistry, high humidity, and extreme Saudi heat. Choosing the right type helps prevent weakening, chemical reaction, or loss of support over time, especially in coastal Jeddah projects or high-temperature Riyadh sites, protecting rebar position and slab durability.
The minimum is determined by the structural drawings, slab type, and rebar layout. Use enough chairs to support the full rebar mesh without loose, unsupported bars. Light slabs may need fewer, while heavy-duty industrial floors or high-load slabs need more chairs to prevent rebar dropping and protect the concrete cover.