Which condition indicates that floating is appropriate to begin finishing?

Which condition indicates that floating is appropriate to begin finishing?

• A. Paste on surface
• B. Bleed water sheen present
• C. Bleed water sheen gone
• D. Surface is cold

Answer: (C)

Finishing should begin when the surface has begun to set enough that there is no free water on top. The presence of bleed water and a visible sheen means the surface is still too wet and finishing tools would push water and cement paste around, creating laitance and a weak, washed finish. When the bleed water sheen has disappeared, the surface has shed most of that excess water, allowing the concrete to be compacted and leveled properly without dragging moisture to the surface. At that point you can achieve a smooth, uniform finish. If you see paste on the surface, that indicates excess cement paste or laitance, which isn’t ideal for finishing now, and finishing at that moment can trap or smooth over the laitance. A surface that’s cold doesn’t reliably indicate readiness for finishing, since temperature alone doesn’t reflect surface moisture or set.

Finishing should begin when the surface has begun to set enough that there is no free water on top. The presence of bleed water and a visible sheen means the surface is still too wet and finishing tools would push water and cement paste around, creating laitance and a weak, washed finish. When the bleed water sheen has disappeared, the surface has shed most of that excess water, allowing the concrete to be compacted and leveled properly without dragging moisture to the surface. At that point you can achieve a smooth, uniform finish.

If you see paste on the surface, that indicates excess cement paste or laitance, which isn’t ideal for finishing now, and finishing at that moment can trap or smooth over the laitance. A surface that’s cold doesn’t reliably indicate readiness for finishing, since temperature alone doesn’t reflect surface moisture or set.