Forms & Formwork

How to choose within forms & formwork

Formwork carries real hydraulic pressure while the concrete is fluid, and the pressure rises with pour height and rate. A form that looks adequate empty can bow or blow out under a full head, which is why bracing and staking are sized for the pour rather than for the geometry.

Material follows reuse. Dimensional lumber and plywood suit one-off residential work. Steel and aluminium systems — Symons and similar — are for repeated use and hold tighter tolerances. Column tubes form round piers and are sized by diameter; form liners impress texture into the finished face.

Release agent goes on before placement, never after, and the wrong one stains the finished surface or interferes with a coating later. Stripping time depends on what the form supports: flatwork edge forms commonly come off at 24 to 48 hours once the concrete holds its own edge, while vertical and structural forms hold considerably longer.

What this category covers

• Wood and plywood forms
• Steel and aluminium systems
• Column tubes
• Form liners
• Release agents
• Ties, stakes and brackets
• Expansion and control joint materials