What Concrete Troweling Is and How to Do It

No one wants an uneven, rough concrete surface, and that’s why it’s so important to trowel finish concrete. Troweling ensures a smooth, sleek appearance on your concrete slab that’s free from imperfections. It can also prevent the likelihood of needing to sand concrete surfaces or otherwise repair them down the road. In this guide, you’ll learn the importance of concrete troweling and how to do it properly.

What Is Concrete Troweling?

Concrete troweling is the process of using a hand trowel (a flat or curved handheld tool) or a power trowel to manipulate the surface of the poured concrete. It’s done after the initial setting of the concrete to create a smooth, dense, and visually appealing finish. After troweling, the surface can dry up before the concrete is sealed.

Troweling involves smoothing out ridges, filling voids, and compacting the concrete, resulting in a level and even surface. This is a crucial step in the concrete finishing process. It not only enhances the aesthetics of the surface but also improves the material’s durability and resistance to wear and tear. A trowel finish ultimately helps to prevent future damage and manage the overall cost of polished concrete floors.

When to Trowel Concrete

The timing of troweling is critical to achieving that perfectly smooth surface. It's important to allow the concrete to reach the proper stage of hardness before starting the troweling process.

Concrete’s setting time varies based on factors like temperature, humidity level, and the type of concrete mix. A general rule of thumb is that concrete is ready for troweling when it is firm enough to support the weight of the troweling equipment but still pliable and not fully cured. This often occurs between the first few hours and a day after pouring the concrete, depending on the conditions.

Concrete should be at the correct consistency, referred to as the "plastic state," which allows it to be troweled without causing excessive bleeding or surface damage. Perform a thumbprint test or look at the surface moisture to determine when the concrete is ready for troweling. 

Factors like ambient temperature, wind, and humidity can also affect the troweling window. It's important to strike a balance between timing and weather conditions to achieve the perfect concrete trowel finish.

Trowel Finish vs. Float Finish Concrete

While concrete troweling and floating are often used interchangeably, they are actually separate and distinct processes. Concrete floating is performed earlier in the curing process and involves using a float. This tool is one that is flat or rounded, and it’s used to level and compact the concrete surface. Floating prepares the concrete for troweling by reducing surface imperfections and closing the surface pores. 

Troweling is performed after floating and focuses on achieving a final smooth finish. It also delivers the additional compaction needed for strength.

Benefits of Concrete Troweling

A crucial step in the concrete construction process, troweling is extremely beneficial. To ensure durability, aesthetics, and easy future maintenance, a trowel finish isn’t something you’ll want to cut in your concrete project. Here are just a few benefits of concrete troweling:

• Ensures the longevity and performance of your concrete surface 

• Minimizes the potential for cracking

• Improves resistance to moisture penetration

• Helps eliminate surface imperfections, such as air voids and bug holes

• Makes a surface that’s easier to clean and maintain

Drawbacks of Concrete Troweling

Before you go ahead and move forward with concrete troweling, you should consider its drawbacks, including the following:

• It can be difficult to find the right balance between weather and timing to ensure the ideal concrete trowel finish.

• For the best results, you must use proper techniques and pay meticulous attention to detail. 

• Paper trowels can be expensive to buy or rent, and hand trowels require a significant amount of manual effort.

• A large-scale concrete troweling project may be unrealistic to do yourself and might warrant the help of a professional.

Hand Trowel vs. Power Trowel: Which Should Be Used?

When it comes to troweling, you have the option of using a hand trowel or a power trowel. Both have their benefits and drawbacks.

As you can see, the choice between a hand trowel and a power trowel depends on the scale of your project, your comfort level with finishing concrete, and possibly even your budget.

How to Trowel Finish Concrete

Having an aesthetic and durable trowel finish will certainly help manage the overall cost of a concrete slab. However, achieving this requires proper technique and attention to detail. Here is a step-by-step guide to help you through the process:

1. Gather all the tools and safety equipment you’ll need for troweling. This includes steel hand trowels, gloves, kneeboards, and safety gear if you’re using a power trowel. 

2. Be sure that the wet concrete surface is cleared of any debris.

3. Hold the trowel at a slight angle and start troweling at one end of the concrete slab.

4. Apply pressure consistently and evenly and push the trowel forward with a smooth motion.

5. Slightly overlap each pass of your trowel for an even finish.

6. Adjust the angle of the trowel as you work to ensure the desired smoothness.

7. Keep the trowel clean by periodically wiping off any excess concrete buildup.

8. Repeat the troweling process, gradually reducing the pressure and angle of your passes as the concrete sets.

9. Avoid over-troweling, as it can cause surface defects and weaken the concrete.

10. Regularly check the concrete surface for any imperfections throughout the troweling process and correct them right away.

DIY vs. Hiring a Pro to Trowel Concrete

While troweling concrete can be a DIY project, there are instances where hiring a professional is recommended. Consider calling in your local concrete finishing professional in the following situations:

• Large-scale projects that require extensive troweling and expertise

• Complex designs or decorative finishes that demand precision and skill

• Limited experience or lack of confidence in handling troweling equipment

• Time constraints or the need for faster completion

• A flawless finish is crucial for aesthetic or functional reasons

Veronica Sparks contributed to this piece.