How do you identify when to perform the first trowel pass?

• A. When the surface is still very wet
• B. When the surface has stiffened and will not drag or smear easily
• C. Immediately after screed
• D. After bleed water has completely evaporated and the surface is hard

Answer: (B)

The moment you perform the first trowel pass is when the surface has stiffened enough to support the trowel without dragging or smearing. At this point the concrete has started to set and bleed water has subsided, so the surface is firm enough to smooth without pushing excess water or laitance around. If you trowel while it’s still very wet, you’ll smear water and fine materials, creating a weak, dusty finish and often needing rework. If you wait too long and the surface becomes too hard, a trowel pass won’t produce a smooth, dense finish and may leave noticeable tool marks. So the best moment is when the surface is stiff but still workable, not dragging or smearing under the trowel.