Forming a Curved Concrete Walkway: Flexible Form Materials and Techniques

A 31-ft curved walkway (4 ft wide, 4" thick) requires forms that bend smoothly. Several materials work, each with trade-offs.

Forming Options

• Masonite (1/4" hardboard): Rip into 4"×8' strips. Cheap, bends easily. Screw to stakes (hard to nail). Degrades after 1-2 uses when wet.
• HardiBacker / Cement Board: More durable. Pre-wet for flexibility. Screw to stakes. Reusable many times.
• Kerfed 1×4 Lumber: Cut 1/4" deep slots 1/2" apart on back. Bends well, strong, reusable. Labor-intensive to kerf.
• Vinyl Trim Forms (2", 4", 6"): Professional, reusable indefinitely, easy to bend. Expensive ($2-4/ft).

Layout Technique

1. Use garden hose to design curve on ground.
2. Drive stakes every 2-3 ft along curve.
3. Attach form material, checking with level for consistent height.
4. Brace outside of curve with extra stakes—concrete pressure pushes out.

Pouring Tips

• Order concrete with 3/8" pea gravel for easier placement in curves.
• Use a 2×4 screed on form tops.
• Bull float, then broom finish with handle extensions.
• Cure 7 days (wet burlap or curing compound).

For a one-time project, Masonite or kerfed lumber balances cost and performance.