When Should You Finish Concrete?

You should finish concrete after the bleed water is all gone. This is the critical stage to begin the final finishing process.

Understanding the Concrete Finishing Timeline

Finishing concrete isn't a single step but a process that happens at different stages as the concrete cures. However, the crucial final finishing steps, often done with tools like a steel finishing trowel, should only commence once specific conditions are met.

The Importance of Waiting

Immediately after concrete is placed and screeded, a process called "bleeding" occurs. During bleeding, heavier solid particles settle, forcing excess water to rise to the surface. This water is known as bleed water.

Reference Insight: As the provided reference states, you must "Allow all of the water to disappear before you do anything else."

Attempting to finish the surface while bleed water is still present can cause significant problems, such as:

• Weakening the surface layer
• Creating a dusty or scaling surface
• Reducing durability

When is the Right Time?

The precise moment to begin final finishing is directly tied to the disappearance of this surface water.

Reference Insight: The reference explicitly says, "After the bleed water is all gone you can get out your steel finishing trowel and put on the final touches."

The time it takes for bleed water to disappear varies greatly depending on several factors:

• Temperature: Warmer temperatures typically speed up drying.
• Humidity: High humidity slows evaporation.
• Wind: Wind increases evaporation rates.

Reference Insight: This variation is highlighted in the reference: "This can take 20 minutes or 4 hours depending on the temperature, humidity and how hard the wind is blowing."

Therefore, the timing isn't fixed but is determined by observation of the concrete surface itself.

How to Check for Bleed Water

Checking is simple:

1. Visually inspect the entire surface for any standing water or a wet sheen.
2. If unsure, gently press your finger onto the surface in an inconspicuous spot. If water wells up around your finger, bleed water is still present.

Wait until the surface appears dull and firm enough to withstand finishing tools without excessive displacement.

Summary of Finishing Stages

While waiting for bleed water, initial steps like screeding and bull floating are performed. The finishing stages typically follow this sequence:

• Screeding: Leveling the concrete surface immediately after placing.
• Bull Floating/Darbying: Pushing down aggregate and filling voids while the concrete is still wet.
• Waiting for Bleed Water to Disappear: The crucial holding period.
• Edging & Grooving: Cutting control joints and finishing edges once the concrete can support the tools.
• Troweling (Floating & Final Troweling): Smoothing and compacting the surface. This often starts after bleed water is gone (floating) and is completed with steel troweling for a smooth, hard finish (final troweling).

In conclusion, the transition from initial preparation to final troweling depends entirely on the concrete losing its surface bleed water.