Darby

Definition

A Darby is a hand-manipulated straightedge, usually 3 to 8 feet long, used in the initial leveling of wet concrete or plaster surfaces.

Purpose

The purpose of a Darby is to achieve a smooth, level surface during the early stages of concrete or plaster application. It helps eliminate high spots and fill in low areas, providing a uniform surface before further finishing processes.

Examples of Use

1. Concrete Flooring: Using a Darby to level freshly poured concrete for a floor slab, ensuring an even base before troweling.
2. Plaster Walls: Applying a Darby to smooth out wet plaster on walls, creating a flat and uniform surface for finishing.
3. Swimming Pools: Leveling the wet concrete of a pool's interior surface with a Darby before applying the final smooth finish.

Related Terms

• Float: A tool used for smoothing and finishing the surface of wet concrete or plaster.
• Trowel: A flat-bladed hand tool used to apply, spread, and smooth materials like concrete and plaster.
• Screed: A tool or machine used to level and smooth freshly poured concrete.

Notes

• Proper technique in using a Darby is essential to avoid overworking the material, which can lead to defects.
• Darbying is typically followed by floating and troweling for a fine finish.
• Different materials, such as wood or metal, can be used for Darbies, each with specific benefits.