Finishing concrete requires patience and perfection and that is what stops us from doing it. But trust me it is the most satisfying thing to do. In this article, we’ll show you the tools and techniques needed to achieve a smooth, durable finish on concrete. We’ll also show you how to tell when to prepare the concrete for each stage of the finishing process. Whether you’re pouring a small sliver of concrete, like a pad for your trash can, or a large slab for the patio, these steps will introduce you to the process.
Tools required on how to smooth concrete:
- Rubber gloves
- Magnesium float
- Safety glasses
- Steel trowel
A trowel compacts the surface of the concrete, giving it a smooth appearance. Creating a smooth, durable finish on concrete is a skill you can master only with the right set of tools and practice. We’ll show you the tools and how to use them for each step of the concrete finishing process. And just as important, we’ll help you determine when the concrete is ready for the next finishing step.
Each step of the process must be done with a different tool. You can make a ruler and darby out of scrap wood. The rest you will have to rent or buy. You’ll need a magnesium trowel ($15 to $25), an edger ($5 to $20), a grooving tool ($10 to $30), and a steel trowel ($8 to $40). Professionals buy high-quality, expensive tools that will stand up to the rigors of everyday use, but less expensive versions are available at home and hardware stores and will work just fine for occasional home use.
Concrete is a mixture of Portland cement, sand, aggregate (gravel), and water that hardens when mixed. While there are additives that can slow or speed up the process and special mixtures in bags that harden quickly, in general, the speed of the process is highly dependent on temperature and humidity.
Hot, dry weather speeds up the hardening process, sometimes so much that it is nearly impossible to complete all finishing steps in a timely manner. If possible, work while your project is in the shadows. On cold days, you can spend a long time waiting for the concrete to reach the next stage.
Step1: Screed and darby the concrete right away
Push or pull the screw plate through the forms in a back-and-forth cutting motion. Push the concrete into the low spots on the front of the screed plate. Repeat to remove excess concrete.
Step2: Darby the concrete
Slide the darby over the concrete in overlapping arcs to level the surface, push down any lumps and fill in any blanks. Raise the leading edge slightly but keep Darby level with the surface. Make two passes.
Step 3: Wait for the surface water to disappear
Water will appear on the surface. Wait until this “blood” water and shine is completely gone before profiling, bonding, or smoothing the concrete. Screeding flattens the concrete along the top of the forms and begins the process of forcing large aggregates under the surface.
Your goal is to level the marks and fill in the little holes left by the ruler. In the process, it will force large aggregates down, leaving a solution of cement and sand to fill the surface.
Step4: Edge, groove and float the slab when the sheen is gone
Using the border of the form as a guide, move the border tool from side to side. Raise the front edge slightly. Use long strokes, working overall until you have smooth, rounded edges.
Step5: Create grooves in the concrete
Lay a straight board down with the predetermined markings for the control joints. Roll the router along the straight edge until the tool bed hits the surface of the concrete. After smoothing the slab with Darby, the water will “bleed” off the concrete and settle on the surface. It will soon be re-condensed into concrete. However, it is necessary to wait until it disappears.
Step6: Float and trowel the surface to smooth and compact it
Raise the leading edge slightly when running the magnesium concrete hand trowel over the concrete in large arcs to compact the surface. Blend marks left by Edgar and Grover edges.
Step7: Trowel the surface
Smooth the surface with a steel trowel after it has partially hardened. Hold the pedal almost flat and twist it in large, overlapping arcs while applying pressure. Float the concrete when you are finished grooving and edging. The floating removes edge marks and brings the surface one step closer to the finish. You may need to push the float if the concrete begins to harden. You’ll be surprised that, with enough scrubbing, you’ll be able to get grout even on the surface of a fairly tough slab.
If you are satisfied with the appearance of your floating slab, no further finishing is necessary. Repeat the edging and groove steps after smoothing to refine the grooves and edges. For the decorative effect shown in the inset of Photo 4, run the edger around each section of the slab after the last brush finish.
Step 8: Broom finish for better footing
Drag a broom over the concrete after it floats with a magnesium trowel to create a non-slip surface. Adjust the pressure down to create the desired amount of texture.
Dragging a broom over partially hardened concrete produces a rough texture that provides better traction in slippery conditions Special concrete brooms are available, but a regular push broom will also work.
It can be hard to believe that concrete can be dangerous. But the strong alkalinity of cement can cause chemical burns like a strong acid. By the time you realize you are getting burned, your skin may already be damaged. This is why it is essential to avoid prolonged skin contact with wet concrete.
And why you should be very careful so as not to get the concrete wet in your eyes. Wear rubber gloves, a long-sleeved shirt, long pants, and safety glasses. Wear rubber boots if you must go through concrete. Immediately wash the wet concrete off your skin and remove clothing saturated with concrete.
For a dried concrete finish for an attractive finish check out ways how to sand the concrete perfectly.